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Capillary water, serving as a crucial intermediary between groundwater and crop root layer moisture, is important for both soil retention and crop utilization. To investigate the effect of mulched drip irrigation (MDI) on upward capillary water in cotton fields with different application years (0, 10, 14, 18, 20, and 24 years) in the saline–sodic region of Northwest China, an indoor soil column test (one-dimensional capillary water rise experiment) was conducted. The results showed that the wetting front transport law, capillary water recharge, and wetting front transport rate over time exhibited an increasing trend in the early stages of MDI application (10 and 14 years), peaking at 18 years of application, followed by a decreasing trend. The relationship between the capillary water recharge and rising height was fitted based on the Green–Ampt model, and their slopes reveal that 14 and 18 years of MDI application required the largest amount of water per unit distance, indicating an excellent water-holding capacity beneficial for plant growth. Conversely, 0 years required the smallest amount of water per unit distance. Based on the movement characteristics of upper capillary water, we confirmed that the MDI application years (0–18 years) improves soil infiltration capacity, while the long-term application years (18–24 years) reduces groundwater replenishment to the soil. Furthermore, the HYDRUS-1D model was employed to simulate the capillary water rise process and soil moisture distribution under different MDl application years. The results showed an excellent consistency with the soil column experiments, confirming the accuracy of HYDRUS-1D in simulating the capillary water dynamics in saline–sodic areas. The results would provide suggestions to achieve the sustainable development of long-term drip-irrigated cotton fields. [ABSTRACT FROM AUTHOR]

Mulching is a widely used agricultural water conservation measure in the semiarid regions of Northwest China. In order to explore the response process of different film mulching methods to soil microorganisms, we characterized the effect of different film mulching methods on soil microbial diversity and community structure characteristics in the root zone of drip-irrigated maize during the heading and maturity stages using high-throughput sequencing of 16SrDNA and ITS amplicons combined with bioinformatics analysis. Full mulching (FM) was contrasted to controls of no mulching (NM) and half-mulching (HM), yielding an order of microbial diversity, abundance, and evenness scores of HM > FM > NM. The HM and FM treatments reduced the relative abundance of Proteobacteria and Actinobacteria (the most abundant bacteria) in the bacterial community structure but increased that of Acidobacteria and Chloroflexi. In the fungal community structure, HM decreased the abundance of Sordariomycetes but increased that of Eurotiomycetes (the most abundant fungi). The abundance and community structure of bacteria were significantly correlated with soil temperature and those of fungi with pH. HM improved network complexity and competitive relationships among bacteria, while FM increased the relationship between fungal groups and the symbiosis of fungal communities. HM significantly increased maize yield (20.37% and 6.01% above NM and FM, respectively). In summary, full mulching was more favorable than no mulching for soil microbial diversity and community structure composition, but soil microbial diversity and yield responded better to half-mulching. These results provide a background for improving the yield of drip-irrigated maize and protecting the microbial ecosystems of farmland soils. [ABSTRACT FROM AUTHOR]

To seek the optimal combination of water–air for drip irrigation processing tomatoes in Northern Xinjiang, China, field experiments consisted of four irrigation levels, and two types of gas-filling methods were proposed. Throughout the whole growth period, the water consumption by physical aeration and chemical aeration increased by 13.65% and 9.27%, respectively compared with the nonaerated treatment. Under the conditions of physical aeration, the processing tomato fruit yield and irrigation water use efficiency (IWUE) increased by 8.14% and 4.74%; while by chemical aeration, they increased by 7.91% and 4.61%, respectively. Physical aeration had the most prominent role in increasing the contents of organic acid, soluble solids, soluble sugar, lycopene, and VC in processing tomatoes. The presented indicators show that the effect of physical aeration was better than that of chemical aeration. Physical aeration in combination with different irrigation levels, the 4,950 m3·hm−2 irrigation level gave the highest yield of processing tomato, whereas the highest IWUE was obtained in the 4,500 m3·hm−2 irrigation treatment, and the quality parameters of processing tomatoes at the 4,500 m3·hm−2 irrigation level performed better than those at the 4,950 m3·hm−2 irrigation level. To take into account the requirements of processing tomatoes for maximum IWUE and fruit yield and quality, the entropy weight method was used to determine that the irrigation water volume of 4,500 m3·hm−2 under the conditions of physical aeration can be used as a suitable water and air combination pattern for processing tomatoes in drip irrigation in Northern Xinjiang. [ABSTRACT FROM AUTHOR]

The evaluation of soil particle composition and salt dynamics is essential for promoting the sustainable development of oasis agriculture in arid regions under long-term mulched drip irrigation (MDI). In this study, we employed the space-for-time substitution method to investigate the long-term effects of MDI on soil particle composition and salinity. Additionally, seven fields, with MDI durations ranging from 0 to 16 years, were selected to represent the primary successional sequence though time in Northwest China. Soil samples were collected from three soil depths (0–30 cm, 30–60 cm, and 60–100 cm) and then analyzed in the laboratory for soil particle composition and salt content. Our findings demonstrated that influenced by the depth of mechanical cultivation and the maximum wetting front depth, the long-term application of MDI significantly altered both the structure of soil layers and the composition of soil particles after 8 years. Soil sand content and soil salinity gradually decreased, whereas the content of soil silt and clay increased with increasing MDI duration throughout 0–100 cm soil depth. Furthermore, the rates of soil desalination stabilized after 10 years of MDI application, with desalination levels exceeding 90% in the 0–100 cm soil layer. Additionally, the soil mass fractal dimension (Dm) exhibited an upward trend across 0–100 cm soil depth. The changes in soil particle composition indirectly influenced the variations in Dm and salt content. Our study demonstrated that long-term application of MDI effectively mitigated soil salinity, changed soil structure, and ultimately enhanced soil quality and cotton yield. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cotton (Gossypium hirsutum L.) is the fiber crop most widely cultivated globally and one of the most important commercial crops in China, irrigation is closely related to the growth of cotton. A water temperature for irrigation that is too low or too high inhibits cotton growth. Poor irrigation timing results in water and nutrient deficiencies that reduce cotton yield. Therefore, it is necessary to determine the appropriate irrigation timing and water temperature. METHOD: We conducted an experiment in an arid region of north‐western China to assess the effects of irrigation timing and water temperature on soil temperature and the photosynthetic characteristics, biomass, total nitrogen (N), and seed cotton yield. Two irrigation times (daytime and nighttime) and four water temperatures (15, 20, 25, and 30 °C) were combined into eight treatments. RESULTS: Our results showed that water warming and nighttime irrigation improved the photosynthesis, biomass, N concentration (the proportion of total N weight in the plant biomass, in g kg−1), N content (the mass of total N, in g plant−1), and cotton yield. The optimal water temperature range for photosynthesis was 25.7–28.7 °C. Water warming also boosted the biomass allocation to the stem and increased the N allocation to the stem and leaf. Nighttime irrigation enhanced these phenomena. Water warming also increased the number of bolls per plant but reduced the single boll weight, increasing the seed cotton yield by 5.88–11.46%. At the same water temperature, irrigation during the night increased the number of bolls per plant and the single boll weight, improving the seed cotton yield by 2.95–4.31%. Among them, NI25 (nighttime irrigation with 25 °C water temperature) increased the yield by 14.13–14.90% compared with CK (daytime irrigation with 15 °C water temperature), which offers the best combination for increasing the yield. CONCLUSION: Our study clarifies the optimal irrigation timing and water temperature for cotton production under drip irrigation with film mulching, providing valuable information for improving the cotton yield in arid areas with temperate continental climate. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Xinjiang is short on freshwater resources and rich in ones. The unregulated use of brackish water for agriculture leads to the aggravation of secondary salinization in soil; however, magnetization can improve the quality of brackish water. To evaluate the effects of magnetized brackish water drip irrigation on the water and salt transport characteristics of sandy soil in southern Xinjiang, China, a field plot experiment was carried out in which irrigation water was treated using one or two water magnetization events at different magnetization intensities. Water was treated at five magnetization intensities: 1000, 2000, 3000, 4000, or 5000 Gs, while unmagnetized water was used as the control. The results showed that the magnetization of brackish water used in drip irrigation decreased the water transport rate and increased the water holding capacity of the root layer soil. Magnetized irrigation water enhanced the leaching of soil salt and reduced the rate of salt accumulation. Compared with the control, the salt content of the magnetized water-irrigated soil decreased by 15.0%~33.7%, and the salt storage in the magnetized water-irrigated soil decreased by 44.99%~86.78%. The lowest rate of salt accumulation (4.96%) was observed at a magnetization intensity of 3000 Gs. Magnetized water irrigation changed the composition and proportions of soil ions, and Na+, Cl−, and SO42− leaching from the soil increased. The effect of magnetizing the irrigation water twice was greater than that of one magnetization event. Magnetizing the water twice at an intensity of 3000 Gs led to the largest decrease in the relative percentage contents of Na+ and Cl−, which were 80.90% and 82.36%, respectively. The magnetization intensity had a significant effect on the soil carbon and nitrogen contents, which showed a trend of first increasing and then decreasing as the magnetization intensity rose. The total carbon content after irrigation with magnetized water increased by 13.48%~63.35%, and the total nitrogen content increased by 11.73%~147.96%. The magnetization treatment of irrigation water can therefore reduce the risk of soil salinization and reduce salinity stress on crops in arid regions, providing a new method for alleviating the shortage of freshwater resources in Xinjiang and a means to use brackish water safely while improving salinized soil. [ABSTRACT FROM AUTHOR]

To improve the irrigation quality and anti-clogging performance of the emitter, it is necessary to design and optimize its flow channel structure. The shunt-hedging drip irrigation emitter (SHDIE) flow channel is a new type of flow channel. Using computational fluid dynamics, by setting different conditions (such as particle size and injection position), the motion trajectory of sand particles and flow field distribution characteristics of the shunt-hedging flow channel were simulated. According to the simulation results, a new anti-clogging structural optimization scheme was proposed, and physical experiments verified its feasibility. The results showed that the flow index of the original flow channel (SHDIE1) and optimized flow channel (SHDIE2) were 0.479 and 0.486, respectively, which mainly relied on the shunting and hedging of water flow to energy dissipation. For sand particles with diameters of 0.05, 0.10, and 0.15 mm, the average values of the velocity amplitude ratio, η, were 0.9998, 0.9994, and 0.9991, respectively; the average values of the velocity phase difference, β, were −0.143°, −0.320°, and −0.409°, respectively. A larger sand particle diameter led to worse followability and a higher risk of blocking the channel. When the sand particles collided with the sensitive region of the flow channel, their movement direction would suddenly change, entering the vortex area. After colliding with the sensitive region of edge A, the maximum probability of sand particles entering the vortex area was increased to 87.5%, and then they stayed in the vortex area under the effect of the sensitive regions of edges B and C. After the sensitive regions were removed, the motion trajectories of sand particles became regular and smooth. The optimized flow channel's (SHDIE2) anti-clogging performance was greatly improved by 60%, with a 1.46% loss of hydraulic performance. This study can provide theoretical support for designing the high anti-clogging emitter. [ABSTRACT FROM AUTHOR]

Biochar as an organic soil conditioner has colossal application potential. Many recent studies revealed the influence of biochar on the soil during the crop growth period. However, few studies considered the effect of seasonal freeze-thaw on biochar's improvement effect. Therefore, we conducted a field experiment to observe the impact of biochar on soil and cotton (Gossypium hirsutum L.). We used four biochar application rates (0.33%, 0.66%, 1.00%, and 1.33% of soil mass fraction) and applied biochar in the cotton field before and after seasonal freeze-thaw, respectively. The results showed that applying biochar after freeze-thaw was more effective on soil water storage and soil temperature preservation during the cotton growth period. Moreover, applying biochar with 0.66% soil mass fraction after freeze-thaw improved the cotton biomass by 5.31~36.13%, leaf area index by −10.82~32.52%, and seed cotton yield by 3.88~21.98%. Based on the principal component analysis of cotton fiber quality, we found that 0.66% biochar application after freeze-thaw improved cotton fiber most significantly. In total, applying biochar at 0.66% soil mass fraction after freeze-thaw was the most optimal application mode for improving soil hydrothermal conditions, cotton growth, and fiber quality. Our study can provide a scientific reference for applying biochar in northern Xinjiang, China. [ABSTRACT FROM AUTHOR]

The sustainable development and utilization of saline-alkali land are closely related to holding fast the minimum cultivated land area of China. The change of soil salt in cotton field under long-term mulched drip irrigation (MDI) is connected with the development of the national cotton industry. From 2015 to 2019, five cotton fields with different applying years of MDI, which were reclaimed in 2004, 2008, 2010, 2012 and 2015 respectively and were saline-alkali wasteland before, were monitored continuously in the Manas River irrigation area of Xinjiang. By means of continuous location monitoring and spatial–temporal variability (For example, the monitoring data of cotton fields under MDI in 2004, 2008, 2010, 2012 and 2015, and in the year of 2015 were counted as 12, 8, 6, 4 and 1 years, respectively), the spatial–temporal variations of soil salt and ions in cotton field with 1-16a MDI technology were presented. The cotton growth characteristics and its main influencing factors were also analyzed in the study. The results showed that saline-alkali cotton field experienced changed from intensive saline soil to moderate saline soil and finally to non-saline soil under long-term MDI. The change of soil salt and the response of cotton growth to soil salt were divided into three typical stages. Firstly, soil desalinated rapidly in 1-4a MDI cotton field, which the annual average desalination rate was 24.93% in 0–100 cm soil layer (root zone). Additionally, the survival rate of cotton rocketed from 1.48% to 42.04%, and yield increased sharply from 72.43 kg ha−1 to 3075.90 kg ha−1. Soil desalination was lower in 5-11a MDI cotton field, which the annual average desalination rate was 10.92% at the root zone. The annual survival rate and yield of cotton increased by 6.26% and 5.18%, respectively. After 12a MDI, the soil salt in cotton field tended to be generally constant, which the average salt content in root zone was less than 2.49 g kg−1. The survival rate of cotton was stable above 90.39%, and the yield per unit area exceeded 5401.32 kg ha−1. Ions, sodium absorption ratio and Cl− and SO42− equivalent ratio (CSER) in cotton soil also decreased with the extension of MDI. Salt composition changed year by year, but the type of intensive saline soil had always been chloride-sulphate solonchak (0.2 < CSER < 1). In practice, with a higher irrigation quota and ideal irrigation water quality, the soil salt environment of saline-alkali soil MDI cotton field had developed in favor of cotton growth in an oasis irrigation area. However, this management practice caused between 124.21–143.61 mm of water resources waste. Therefore, we should further enhanced the consciousness of water-saving and implemented quota management in practice. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Four biodegradable films were tested to replace PE films in cotton fields under mulched drip irrigation. • Film degradation, soil salinity, residue film accumulation, yield, and WUE were compared. • Degradation process and accumulation of residual film were different between tested films. • Thicker PBAT films and PE films performed similarly in improving cotton yield. • Due to the least accumulation of residual film and highest yield, thicker PBAT films were recommended. To alleviate soil pollution caused by mulching polyethylene (PE) films that are non-degradable and non-recoverable, we evaluated different biodegradable (BD) films (starch-polymer, polybutyrate adipate terephthalate or PBAT, and butylene succinate-co-butylene adipate or PBSA) as alternatives to PE films for mulched drip irrigation in a cotton (Gossypium hirsutum L.) field in Xinjiang, the largest cotton-planting region in China. Film degradation, soil salinity, residue film accumulation, cotton yield, and water use efficiency (WUE) were compared between BD and PE films in two consecutive years (2015–2016). We found that the accumulation of residual film was significantly stronger in plots covered by PE films than by BD films. At the early stage of cotton growth, BD and PE films performed similarly in conserving water in topsoil (0–40 cm depth). Degradation of BD films initiated 40–60 days after sowing. Thus, at the late stage of cotton growth, PE films remained intact and were more effective than BD films in wetting the soil. Due to the drier soil, soil salinity in plots covered by BD films was higher than those by PE films. PBAT films showed a slower degradation process than PBSA and starch films under the mulching condition but degraded more completely after buried in soil. After mulched drip irrigation was managed for two years, cotton yield showed no significant difference between plots with PE films (5722 kg ha−1) and those with thicker PBAT films (5699 kg ha−1). However, mulching PE films resulted in a significantly higher WUE than BD films. Therefore, we suggest thicker PBAT films (with the highest yield and WUE and the lowest accumulation of residual film) as potential alternatives to PE films to improve cotton yield and control soil pollution under mulched drip irrigation. [ABSTRACT FROM AUTHOR]

Highlights • Biodegradable and plastic mulches were compared in drip irrigated cotton fields. • All mulches were effective in soil water and heat conservation and increasing yield. • Two biodegradable mulches performed similarly to plastic mulch in enhancing WUE. • Commercially available biodegradable mulch can be an alternative to plastic mulch. Abstract Biodegradable mulches are advocated as an alternative to plastic mulches. Here, we carried out an experiment in Xinjiang, an arid region in China, to demonstrate the effects of mulching biodegradable films under drip irrigation on soil conditions and cotton (Gossypium hirsutum L.) yield in 2015 (with less precipitation) and 2016 (with more precipitation). Plastic mulch made from polyethylene (PE) and four types of biodegradable mulch were compared, namely, BD1 to BD4, with different levels of thickness and induction periods. Our results indicated that PE mulch was the most efficient in soil water and heat conservation. Biodegradable mulches performed similarly in warming the soil in both years, which increased topsoil (5–20 cm depth) temperature than no mulching in the cropping season by 0.66 °C and 0.61 °C in 2015 and 2016, respectively. The effect of mulching on increasing soil water storage was stronger in the wet year. The increased soil water storage (0–100 cm depth) by biodegradable mulches than no mulching was 113 mm and 194 mm in 2015 and 2016, respectively. Earlier onset of the phenological events of cotton growth was similar between PE mulch and biodegradable mulches. Mulching shortened the number of days from sowing to cotton maturity by 4 days and 10 days in 2015 and 2016, respectively. Compared with no mulching, biodegradable mulches achieved better performance in enhancing cotton yield and water use efficiency (WUE) in the dry year (916 kg ha−1; 1.85 kg ha−1 mm−1) than in the wet year (568 kg ha−1; 1.22 kg ha−1 mm−1). Although PE mulch resulted in the highest yield, there was no significant difference in WUE between PE mulch and BD1 or BD2. Therefore, some of the commercially available biodegradable mulches can be used as a competitive alternative to plastic mulch to enhance crop yield and control soil pollution. [ABSTRACT FROM AUTHOR]

Without an efficient mulch film recovery, the residual plastic film (RPF) causes pollution hazards to agronomic systems and natural environments. Here, we examined the distribution characteristics of RPF in the topsoils (0–40 cm) in an oasis agroecosystem in Northwest China. After cotton harvest in 2016, we collected 2304 soil samples from six cotton fields with different years of continuous mulching management (5, 9, 11, 13, 15 and 19 a). A total of 2471 pieces of RPF were separated and weighted. The weight of each RPF fragment was calibrated by its size measured in digital images. Our results showed that the amount of RPF ranged from 121.85 to 352.38 kg ha –1 across the six fields, remarkably exceeding the national standard of China (75 kg ha –1 ). The occurrence frequency of RPF fragments maximized at 5–15 cm depth. With the increase in soil depth, RPF fragments became smaller, and their total mass decreased linearly. After the constant mulching practice, RPF accumulated at an annual rate of 15.69 kg ha −1 , mainly occurring at 0–30 cm depth. The accumulation of the larger RPF fragments (>25 mg per piece) primarily took place from 5 to 15 years after mulching started. It took over 15 years for the larger RPF fragments to degrade into smaller ones (<25 mg per piece), which accounted for 65% of the total number of RPF fragments in the field with 19-year of mulching. RPF fragments with a weight larger than 100 mg mostly concentrated at the surface (0–10 cm), whereas, the other smaller RPF fragments showed an evident downward migration. That said, with the constant mulching management, RPF pieces became more fragmented and distributed deeper, making mulch film recovery more challenging. To the best of our knowledge, this is the first time that the dynamics of RPF distribution in the soil profile after long-term mulching have been characterized. If the current mulching method continues, the accumulated RPF is going to cause severe soil pollution and risk the sustainability of the oasis agroecosystem. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

When crop roots are in a low oxygen environment for a long time, it will lead to a series of problems. To improve soil oxygen conditions, a method of oxygenation irrigation is increasing the dissolved oxygen (DO) concentration in irrigation water. However, its application effect in a mulched drip irrigation system is not clear. In this study, a field experiment was conducted in Xinjiang to investigate the actual effect of oxygenation irrigation in field planting. We set up mechanical oxygenation (AO), venturi oxygenation (VO), and four chemical oxygenations with different DO concentrations (CO1–4). The results showed that physical oxygenation (AO, VO) was limited by the saturated DO of irrigation water. Compared with venturi oxygenation, mechanical oxygenation could reach the saturated DO faster and had higher stability of DO concentration during single irrigation. The chemical oxygenation was not limited by the saturated DO. The maximum DO in irrigation water would also increase with the increase in the amount of oxygen enhancer, but it needed more reaction time than the physical oxygen to reach a stable state. The oxygenated water would be affected by water temperature and delivery distance in the mulched drip irrigation system, resulting in the continuous decline of DO during the irrigation process. For those oxygenated water with saturated DO under different oxygenation methods (AO, VO, and CO1), when they entered the soil, there was no significant difference in the changing trend of DO. In an irrigation process, with the increase of DO, the actual oxygenation efficiency in the soil also increased. The DO concentration of irrigation water was increased from 3.9 mg L−1 to 9.1 mg L−1, and 10 times of irrigation was carried out during the crop growth period, then soil oxygen could be increased by an average of 6.72∼6.89%. By increasing the DO of irrigation water, the soil oxygen condition of mulched drip irrigation can be improved. Under the condition of saturated DO, each oxygenation irrigation had no significant impact on the soil physical and chemical properties. After two years of irrigation, the chemical oxygenation using sodium percarbonate had increased the soil EC, pH, and Na+ content, which means slightly intensified the soil salinization. • The DO concentration of water in drip irrigation tube is inversely proportional to conveyance distance and water temperature. • The DO concentration of water increases from 3.9 mg L−1 to 9.1 mg L−1, the soil oxygen can be average increased by 6.7–6.9%. • Chemical oxygenation irrigation has the risk of aggravating soil salinization. [ABSTRACT FROM AUTHOR]

Biodegradable films are considered an environmentally-friendly alternative to traditional polyethylene (PE) film mulches, as they effectively reduce film pollution in the farmland when using mulched drip irrigation. However, the effects of different degradable films on soil micro-climate and maize growth have not been examined, especially under different irrigation amounts, which are critical considerations for oasis agriculture in arid areas. Therefore, we conducted a field study in 2019–2020 on maize farmland using two biodegradable films, one with an 80-day induction period (M 80) and the other with a 100-day induction period (M 100), and compared them with traditional PE film (M PE). Four irrigation amounts (4875, 5250, 5625, and 6000 m3 ha−1) were tested. Our results showed that weight loss rates of M 80 and M 100 were 7.21 times and 9.63 times higher than that of M PE , and this degradation process was slowed down with increased irrigation amounts. We attribute this mitigation to changes in soil moisture and the physiological characteristics of the crop. Using film of higher resilience together with higher irrigation amount resulted in more active photosynthesis and fluorescence, especially at the later maize growth stage, and improved maize yield compared to the other degradable film. In addition, the reduction in maize yield caused by the use of biodegradable films could be largely compensated for by applying higher irrigation amounts. Our findings recommend using M 100 with an irrigation amount of 5625 m3 ha−1 for maintaining maize yields while reducing plastic pollution. [Display omitted] • Biodegradable films significantly reduce film residuals in maize field. • Mulching with films and irrigation amounts together control maize growth. • Yield reduction by using biodegradable films was compensated by higher irrigation. [ABSTRACT FROM AUTHOR]

Preferential flow in soil has a potential impact on the maintenance of the agricultural ecosystem. The aim of this study was to quantify and evaluate the characteristics of preferential flow in drip irrigation cotton fields in Xinjiang. We applied the dye tracer method, addressed the variability in stained images, collected soil samples in the excavated soil profile, and calculated the fractal parameters in four key growth stages of cotton in 2021. According to the dyeing mode, the dyed area ratio tended to keep decreasing from the soil surface; a down movement of points which drastically dropped to zero appeared at pace with the growth of the cotton (from −10 cm to −30 cm). Statistics obtained from the staining images showed that the preferential flow degree was highest at the boll opening stage; no significant difference in non-uniformity emerged from different treatments at the same growing stage (p > 0.05). Conversely, the fractal feature parameters in the active region model probed that the preferential flow degree was developed at the flowering & bolling stage in treatments with opaque oxidation-biodegradable film mulching (B,W), and at boll opening stage with plastic film mulching (P). During the same growth period, a significant difference (p < 0.05) existed between different groups. In comparison, the fractal feature parameter was found more adequate and effective in evaluating the characteristics of preferential flow in drip irrigation cotton fields. This research will provide practical information for the local department to adjust some agronomic measures to reduce the risk of low irrigation water utilization efficiency. • Dyed area ratio had a tendency of keeping decreasing from soil surface. • Finger flow mainly appeared in the soil at the early cotton growth stage. • Macropore flow primarily developed with the maturing stages of the cotton. • Fractal feature parameter was comparatively effective to evaluate the preferential flow. [ABSTRACT FROM AUTHOR]

Drip irrigation frequency has important impacts on crop growth, soil moisture, nutrient, salinity and substances' accumulation in the irrigation system as well as drip irrigation emitter clogging. However, previous studies on reasonable drip irrigation frequency merely focused on crop yield and quality, soil water and salinity transporting, neglecting its impact on the high-efficiency operation of the drip irrigation system. Studies on reasonable reclaimed water drip irrigation frequency were more insufficient. Therefore, the drip irrigation emitter clogging experiment using reclaimed water was accomplished in the wastewater treatment plant, and then, the effects of different irrigation frequencies, including once/2 days (IF), once/4 days (IF), once/8 days (IF) and once/16 days (IF), on dynamic emitters' outflows and biofilms' growth were studied. The results showed that emitter clogging degrees increased with shorter drip irrigation interval, mainly because that discharge ratio variation (Dra) and Christiansen uniformity coefficient (CU) both decreased. After the system accumulatively run 540 h, the smallest Dra and CU were observed in high-frequency drip irrigation treatment (IF) as 30.98 and 31.97 %, respectively, along with the highest proportion of more serious clogged emitters, due to the effects of drip irrigation frequencies on the comprehensive biofilm growth and detachment inside emitters. The dry weights (DWs), extracellular polymeric substances (EPS) and phospholipid fatty acids (PLFAs) of biofilms all increased with shorter irrigation interval, and showed logarithmic relationships ( R > 0.92). The max DW, EPS and PLFAs of biofilms in IF reached 0.124 g, 1459.80 and 96.07 μg, respectively, after 540 h. Combined these with previous studying results, irrigated between once/8 days and once/4 days was believed to be appropriate for planting maize in North China Plain using reclaimed water drip irrigation. [ABSTRACT FROM AUTHOR]

In order to alleviate the shortage of water resources for cotton (Gossypium hirsutum L.) planting in Xinjiang of China, a reasonable amount of nitrogen application under brackish water irrigation was sought. A two-year field experiment was conducted to investigate the effects of nitrogen application rate and irrigation water salinity on seed cotton yield, nitrogen partial factor productivity and fiber quality in Xinjiang under mulched drip irrigation in 2019 and 2020. In this study, we selected four nitrogen application rates (i.e., 100, 200, 300, and 400 kg N ha−1, respectively) and three irrigation water salinity (i.e., 1, 3, and 5 g L−1, respectively). Our results showed that nitrogen application rates and irrigation water salinity significantly affected the seed cotton yield, nitrogen partial factor productivity, micronaire, fiber length, fiber strength, uniformity index and elongation. As the salinity of irrigation water increased, seed cotton yield and nitrogen partial factor productivity increased first and then decreased, micronaire decreased, but fiber length, fiber strength, uniformity index and elongation increased. Moreover, seed cotton yield, micronaire, fiber length, fiber strength, uniformity index and elongation increased first and then decreased, and nitrogen partial factor productivity decreased with the amount of nitrogen application. The optimal combination of nitrogen application rate and irrigation water salinity were 200 kg N ha−1 and 5 g L−1 by principal component analysis. We concluded that the normalized relative value of seed cotton yield and comprehensive evaluation value was 0.85, when the nitrogen application rate and the irrigation water salinity were 197.04 ⁓ 237.94 kg N ha−1 and 3.60 ⁓ 3.88 g L−1, respectively. • Irrigation salinity affected yield and quality of cotton. • Cotton yield increased first and then decreased with increasing irrigation salinity. • There was no difference among micronaire, fiber length, strength, uniformity and elongation. • Yield and quality of cotton reached the maximum together as affected by irrigation salinity. [ABSTRACT FROM AUTHOR]

Jujube tree yields in dryland saline soils are restricted by water shortages and soil salinity. Converting traditional flood irrigation to drip irrigation would solve water deficit and salt stress. The root distribution reacts primarily to the availability of water and nutrients. However, there is little information about the response of jujube roots to the change from flood irrigation to drip irrigation. In this context, a two–year experiment was carried out to reveal the effects of the change from long–term flood irrigation to drip irrigation on soil water, root distribution, fruit yield, and water use efficiency (WUE) of jujube trees. In this study, drip irrigation amounts were designed with three levels, i.e., 880 mm (W1), 660 mm (W2), 440 mm (W3), and the flood irrigation of 1100 mm was designed as the control (CK). The results showed that replacing flood irrigation with drip irrigation significantly altered soil water distribution and increased soil moisture in the topsoil (0–40 cm). In the drip irrigation treatments with high levels, soil water storage in the 0–60 cm soil layer at the flowering and fruit setting, and fruit swelling stages of jujube trees increased significantly compared with the flood irrigation. After two consecutive years of drip irrigation, the treatments with higher irrigation levels increased root length density (RLD) in 0–60 cm soil depth but decreased that in the 60–100 cm depth. In the horizontal direction, higher irrigation levels increased RLD in the distance of 0–50 cm, while reducing RLD in the distance of 50–100 cm. However, the opposite conclusion was obtained in W3 treatment. Additionally, in the second year of drip irrigation, W2 treatment (660 mm) significantly improved yield and WUE, with an increasing of 7.6% for yield and 60.3% for WUE compared to the flood irrigation. In summary, converting flood irrigation to drip irrigation is useful in regulating root distribution and improving WUE, which would be a promising method in jujube cultivation in arid regions. [ABSTRACT FROM AUTHOR]

The lowering of salt content in the field, especially in arid areas, after consecutive application of mulched drip irrigation (MDI) is of vital importance for sustainable cotton plantation. To elucidate the effects of long-term MDI on soil properties and cotton growth, this paper systematically monitored the soil salinity, ion concentrations and the yield of cotton in the field using MDI consecutively for six years in a typical oasis in Xinjiang, China. The results showed that MDI could significantly change salt distribution in the cotton field. During the six years tested, the soil salt content using MDI declined fast at first, and then the decline rate gradually decreased. In the 1st and 2nd year, the average salt content within 0–100 cm soil layer was larger than 20 g kg−1, which belonging to the saline soil. Then the salt content decreased to 10–20 g kg−1 in the 3rd and 4th year, and the cotton field declined to heavily saline soil. After 5 years of MDI, the soil turned to non-salinized. The Cl− and SO42− equivalence ratio (CSER) also decreased with the increase of application years of MDI. Saline-alkaline land developed from chloride-sulphate solonchak (0.2 < CSER < 1) into sulphate solonchak (CSER < 0.2) after 6 years of MDI. The survival rate of the cotton increased from 1.48% (1 year of MDI) to 76.3% (6 years of MDI), and the yield increased from 72.43 kg ha−1 to 4515.48 kg ha−1. When the average CSER, SAR and the soil salinity in 0–140 cm soil layer decreased to 0.60, 0.98 (mol kg−1)0.5 and 6.25 g kg−1, farmers can achieve a balance between income and expenditure. Moreover, when CSER, SAR, and the soil salinity continuously decreased to 0.44, 0.69 (mol kg−1)0.5 and 0.77 g kg−1, the cotton yield will exceed the average production level of cotton in Xinjiang. Under the current irrigation schedule in the oasis irrigation area, the soil salinity and groundwater level after applying MDI could be conducive to cotton growth. However, this situation had also caused a waste of nearly 200 mm of water resources. Therefore, authors suggested that further research on water-saving irrigation systems suitable for different soil conditions should be carried out, and also the differential quota management in production practice should be adopted. [ABSTRACT FROM AUTHOR]

Integrated with deep learning algorithms, machine vision techniques have emerged as a robust method for the swift and non-destructive assessment of crop moisture status across extensive agricultural landscapes. Within the agricultural sector, where water serves as a crucial resource, especially for cash crops such as cotton, precise monitoring of water status in fields is paramount. This study presents a novel approach for the evaluation of thermal imagery of cotton crops to predict their water status. The research focused on the application of a methodology that harnesses deep learning architectures in tandem with extant local irrigation practices. A considerable dataset, comprising approximately 5200 images, was collected under conditions of submembrane drip irrigation conditions. Cross-validation was employed to evaluate five deep learning models: VGG16, ResNet-18, MobilenetV3, DenseNet-201, and CSPdarknet53 for training and testing purposes. Experimental outcomes indicated that the MobilenetV3 model outperformed other deep learning architectures. It demonstrated exceptional capability in identifying cotton water stress classes, achieving an F1 value of 0.9990, with an average processing time of 44.85 ms. These results underscore the effectiveness of utilizing deep learning algorithms for accurately assessing water stress in cotton under mulched drip irrigation. This establishes a foundational basis for the development of a precise, cost-effective, and real-time monitoring system for the management of water in cotton fields. • The effects of five CNN models for cotton water deficit recognition were compared. • The identification of cotton water deficit under real conditions was realized. • The analysis obtained the most suitable CNN model for actual field use. • This study is helpful to develop a precise irrigation system by machine vision. [ABSTRACT FROM AUTHOR]

Mulched drip irrigation is regarded as an effective water-saving irrigation technique that is adopted widely in dryland regions. However, due to the lack of efficient mulch film recovery, residual plastic film fragments accumulating in soil nowadays pose a risk to agricultural production sustainability. To mitigate the pollution result from polyethylene (PE) film mulching and demonstrate the relationship between soil microenvironment, photosynthetic capacity, yield, and water use efficiency of cotton (Gossypium hirsutum L.) in various mulching practices, a two-year field experiment was carried out to test five mulching practices (sprayable degradable film mulching; biodegradable transparent film with an 80-day induction period mulching; biodegradable transparent film with a 100-day induction period mulching; conventional transparent polyethylene film mulching; no film mulching) in Xinjiang, Northwest China. The results showed that mulching significantly increased soil water content and temperature by 23.83% and 15.01% (average on two years) in topsoil compared to the bare soil surface, associated with a higher plant height, leaf area index, photosynthetic rate and aboveground biomass accumulation. Soil moisture, temperature, and crop height all significantly influenced cotton leaf photosynthetic rate, and soil moisture had the most significant impact (the direct path coefficient was 0.450). The highest cotton yield and WUE were observed in PE film mulching (5480.59 kg ha−1 and 1.35 kg m−3, respectively, average on two years) and the biodegradable transparent film with a 100-day induction period was comparable with PE film in yield increased and reduction of water loss (yield and WUE was 5357.51 kg ha−1 and 1.29 kg m−3, respectively, average on two years). The sprayable biodegradable film also had good wetting and warming effects on soil, but notably, sprayable film performances were still weaker than that in solid films. Compared to solid degradable films mulching, soil moisture, soil temperature, photosynthetic rate, yield, and WUE in sprayable film mulching was decreased by 5.55%, 7.19%, 31.41%, 5.31%, and 8.58% on average, respectively. In general, biodegradable transparent film with a 100-day induction period could significantly improve soil water-heat status, enhance cotton development, reduce water evaporation, increase cotton yield and WUE, which provides a cotton-cultivation option to control residual PE fragments pollution and maintained cotton yield. • Degradable films mulching increased irrigation water availability in Northwest China. • Soil moisture had the greatest impact to cotton leaf photosynthetic rate. • Sprayable biodegradable had a good wetting and warming effects on soil. • The compatibility of water-heat conservation of sprayable film was weaker than solid films. [ABSTRACT FROM AUTHOR]

Drip irrigation has become an application trend of water-saving irrigation technology due to its excellent water-use efficiency. However, the energy dissipation form of the commonly used labyrinth channel is relatively simple, and the corresponding energy dissipation mechanism research is inadequate. This article proposes a new kind of channel structure of drip irrigation emitters based on the structure of scalariform perforation plates in plant xylem vessels. We establish a total of 16 sets of orthogonal structure schemes. Using numerical simulation and physical experiments, the hydraulic performance and energy dissipation mechanism of the perforated drip irrigation emitters (PDIE) are studied. The results show that the flow index of PDIE is 0.4665–0.5266. The hydraulic performance of PDIE in the high-pressure zone is the best, and the flow index is 0.4665–0.5046. As the pressure increases, the velocity of the flow of the upper perforation increases rapidly, the flow ratio decreases, the flow index decreases, and the hydraulic performance improves. To further verify the energy dissipation mechanism, a lower flow ratio and a better hydraulic performance were obtained through appropriately expanding the upper part of the upper perforation inlet to the channel boundary. The research sheds new insights for optimizing the hydraulic performance of PDIE. Results reported here provide a theoretical basis for the structural design of drip irrigation emitters and the energy dissipation mechanism research. [ABSTRACT FROM AUTHOR]

• Cotton yields were significantly increased by drip irrigation with plastic mulching in oasis region. • Drip irrigation with plastic mulching significantly increased soil moisture and temperature. • Drip irrigation with plastic mulching significantly increased soil CO 2 emissions. • Total CO 2 emissions in narrow rows near drip tape were highest, followed by wide rows and bare land. As the second carbon storage pool, soil is easily influenced by human activities. Mulched drip irrigation is a water-saving irrigation technique used widely in arid and semi-arid regions. However, information about the response of CO 2 exchange to mulched drip irrigation, such as the wetter and warmer soil, is limited. To identify the carbon emissions effects of mulched drip irrigation, we carried out a field experiment using drip irrigation with and without clear plastic mulching during the cotton growing seasons of 2015 and 2016. We monitored the temporal and spatial variation of soil moisture, soil temperature, cotton growth stage, biomass, lint yield, CO 2 emissions, and the relationship between soil respiration rate and soil climate. The results showed that plastic mulching drip irrigation increased soil moisture and soil temperature, especially during the early and middle growth stages of cotton. The soil respiration rate was related positively to the higher soil temperature and moisture conditions promoted by plastic film mulching, although the coefficients of determination were low (R2 were 0.480 and 0.205, corresponding p-value was both 0.000, respectively). The highest value of soil respiration was obtained within the narrow rows under the drip tape, regardless of the practice of mulching or not. The soil respiration rate under plastic mulch in the narrow and wide rows were on average 28.35 % and 22.48 % higher than non-mulched control. Meanwhile, the amount of total CO 2 emissions was significantly increased by 25.34 % and 28.90 % in these same rows, respectively (p-values were 0.006 at narrow rows and 0.010 at wide rows in the first year, and 0.000 at same rows in the second year). The differences of CO 2 emission in the bare soil was not significant between mulched plots and non-mulched control (p-values were 0.757 and 0.918 in the first and second growing seasons, respectively). In addition, plastic mulching significantly improved the biomass and yield of cotton, by 61.49 % and 12.83 % on average (p-values were 0.034 and 0.039 in 2015, 0.024 and 0.032 in 2016), respectively. The results indicate that the application of drip irrigation under plastic mulch could increase soil water content and temperature, promote cotton growth, and improve lint yield. However, it may also lead to increased CO 2 emissions, which can intensify the warming of the climate. [ABSTRACT FROM AUTHOR]

Xinjiang is one of the most prolific tomato-planting areas in China. Here, we carried out a two-year (2017–2018) field experiment in Xinjiang to study the effects of different nitrogen (N) application rates on the spatial distribution of water and salt in the root zone, as well as their impacts on the yield and quality of tomatoes under mulched drip irrigation. The ideal ranges of N application rates for tomato yield and quality were examined under different salinity levels. Results indicated that soil water content and salinity increased with soil depth. Soil water content was closely related to soil salinity but not to N. Among the tested application rates, tomato yield was highest under the medium-high N (225–300 kg/ha) and low salt (4 g/kg) treatment. Under the highest salt level (10 g/kg), the low nitrogen treatment (150 kg/ha) was better than the high N treatment (300 kg/ha) at boosting tomato yield. Moreover, we found that salinity had a stronger effect on tomato quality than N. Based on these results, we were able to recommend ideal ranges for N (155–201 kg/ha) and salt (3.56–5.59 g/kg) while both are present in the soil. [ABSTRACT FROM AUTHOR]

Processing tomato is one of the most important economic crops in Xinjiang, China, which was constrained with severe water shortage and extreme arid climate. Alternate partial root-zone irrigation (APRI) may provide an effective way to increase irrigation water use efficiency (iWUE) without yield reduction. However, limited studies concerned about applying APRI in processing tomato plantation have been done, especially combined with drip irrigation to further control the irrigation and improve iWUE. Therefore, the two-year pot experiments were conducted to study the effects of different irrigation treatments, including three APRI treatments (irrigation quota of 67.5, 51.6, and 43.7 mm, respectively), fixed partial root-zoon drip irrigation (FPRI, 67.5 mm) and conventional drip irrigation (CDI, 67.5 mm). The results indicated that APRI was an appropriate irrigation method in processing tomato plantation in arid desert area such as Xinjiang, as high irrigation quota of APRI (APRIH) significantly improved its yield without fruit quality reduction in comparison with those of CDI. However, the yield without fruit quality of FPRI significantly decreased. Even if the irrigation quota of APRI decreased to the medium level (APRIM, 51.6 mm), iWUE by increased 31.8–32.7% on the contrary, as irrigation water was saved by 23.6%; while keeping the yield and fruit quality. Therefore, APRIM is recommended for processing tomato plantation in arid northwest China, to increase plant growth, fruit quality, yield, and iWUE synergistically. [ABSTRACT FROM AUTHOR]

Exploring the effect of irrigation on biodegradable film-covered drip-irrigated maize is essential for sustainable agricultural development in arid areas. These regions, like Xinjiang in China, are home to suitable irrigation and biodegradable films. Through field trials, four levels of irrigation, and two biodegradable films and one common polyethylene film were set up to study the effects of different treatments on the physiology, growth indicators, and yield of maize. The results showed that the effects of irrigation and biodegradable films on the photosynthetic index and fluorescence index of maize reached a very significant level (p < 0.01). The effect of single factor irrigation and biodegradable films on the photosynthetic index and fluorescence index of maize reached a significant level (p < 0.05). The photosynthesis index, fluorescence index, plant height, LAI (leaf area index) and yield of W3M3 treatment had the highest value, when compared with other treatments. The W1M1 treatment had the lowest value. The photosynthesis index, fluorescence index, plant height, LAI, and yield of the W3M2 treatment were second only to W3M3. In addition, the output was only 40 kg ha−1 less than W3M3. W3M2 has the best treatment effect from a perspective of sustainable agricultural development and efficient water saving; the optimal irrigation amount was 5625 m3 ha−1, induction period was 60 d, and thickness was 0.01 mm. The results of this study are of guiding significance for the promotion of the use of biodegradable films, search for suitable irrigation, and development of low-carbon agriculture. [ABSTRACT FROM AUTHOR]

Studying water–fertilizer coupling effects in a drip irrigation system is critical for sustainable agricultural development in arid areas, such as that of Xinjiang in China, to find out the optimized water and fertilizer management. Therefore, a two-year field experiment was conducted to find out how the combination of three levels of irrigation quotas and three levels of fertilizer amounts would affect the physiological and growth indexes of jujube, as well as ascertain the differences between drip irrigation and flood irrigation. The results showed that the interacted and coupled effects of irrigation and fertilization influenced most of the physiological indicators and growth indexes. On the other hand, the physiological and growth indexes were increased after transferring flood irrigation to drip irrigation, as the maximum chlorophyll content (CC) and photosynthetic nitrogen use efficiency (PNUE) values increased on average by 6.00%, and 11.39% in 2016, and 1.47% and 6.83% in 2017, respectively. Undoubtedly, inappropriate water and fertilizer management had negative impacts on jujube growth and yield. Based on the treatments and results in this paper, low fertilizer and moderate irrigation would be the best choice. The crop yield, irrigation water use efficiency (iWUE), and fertilizer partial productivity (PFP) increased by 6.77%, 29.48%, and 193.62% in 2016, and similar increments were also found in 2017 of 6.17%, 78.72%, and 133.06%, respectively. This indicated that fertilizer efficiency was promoted along with water use, and in turn, the water amounts were adjusted by the amount of fertilizer that was applied. Based on a comprehensive consideration of the physiological and growth indexes, a mathematical model was established, and the optimized irrigation and fertilizer amounts of jujube in northern Xinjiang area were found to be 815 mm and 400 kg ha−1 (with N–P2O5–K2O proportioned at 2–1–1.5). The results that were obtained in this paper would provide theoretical reference to the sustainable development of jujube plantation using drip irrigation in the arid areas. [ABSTRACT FROM AUTHOR]

Enhancing crop nitrogen absorption is crucial for improving nitrogen fertilizer utilization efficiency. Soil oxygen conditions play a vital role in influencing crop nutrient uptake. However, the impact of dissolved oxygen concentration in irrigation water on cotton's nitrogen absorption remains unknow under mulched drip irrigation conditions. RESEARCH QUESTION: This study aimed to investigate whether the dissolved oxygen concentration in irrigation water affects cotton's nitrogen uptake. METHODS: Urea was utilized as the nitrogen fertilizer, and 5 dissolved oxygen concentration of irrigation water were set in the experiment by adding sodium percarbonate (CK: 3.9 mg L−1, CO1: 9.2 mg L−1, CO2: 13.3 mg L−1, CO3: 17.3 mg L−1, CO4: 25.5 mg L−1). RESULTS: The results showed that increasing the dissolved oxygen concentration in irrigation water could increase the soil urease activity and bacterial operational taxonomic units (OTU), which may be beneficial to the urea decomposition and nitrogen cycling function. Towards the end of the cotton growth period, oxygenation irrigation led to an increase in nitrate nitrogen and ammonium nitrogen content in the soil. The average nitrate nitrogen content in the 0–60 cm soil layer of CO1, CO2, CO3 and CO4 increased by 12.4 %, 14.7 %, 15.9 % and 17.3 % respectively compared with CK. Similarly, the average ammonium nitrogen content of CO1, CO2, CO3 and CO4 in the 0–40 cm soil layer increased by 8.9 %, 11.7 %, 12.0 % and 11.6 % respectively compared with CK. Increasing the dissolved oxygen concentration in irrigation water resulted in elevated dry matter accumulation in cotton. The total dry matter of CO1, CO2, CO3 and CO4 increased by 9.5 %, 12.6 %, 14.6 % and 16.8 % respectively compared with CK. Additionally, the nitrogen concentration in each cotton organ also exhibited an increase. The total nitrogen accumulation of CO1, CO2, CO3 and CO4 increased by 26.1 %, 36.2 %, 48.2 % and 53.1 % respectively compared with CK. Furthermore, increasing the dissolved oxygen concentration in irrigation water also facilitated nitrogen migration to cotton bolls (boll shell + seed + fiber). The cotton boll nitrogen accumulation of CO1, CO2, CO3 and CO4 increased by 1.8 %, 3.4 %, 4.2 % and 4.2 % (absolute value) compared with CK (reached significant level). Finally, the lint yield and fiber quality parameters (micronaire, fiber elongation, fiber breaking strength) exhibited further improvement with the increase in dissolved oxygen concentration in irrigation water. CONCLUSIONS: Increasing the dissolved oxygen concentration in irrigation water promotes nitrogen absorption in cotton, facilitates nitrogen accumulation in cotton bolls, and enhances nitrogen fertilizer utilization efficiency. Moreover, it positively impacts cotton lint yield and fiber quality. • Soil oxygen conditions will affect crop nutrient absorption. • Increasing the DO in irrigation water can improve soil urease activity. • Increasing the DO in irrigation water can promote cotton nitrogen uptake in mulched drip irrigation. • With the increase of DO in water, the proportion of nitrogen accumulation in cotton boll increased. [ABSTRACT FROM AUTHOR]

Soil aggregate stability is critical to ensure the provision of agricultural land. Mulched drip irrigation (MDI) is widely used in arid region of northwest China, but the response of soil aggregate stability to soil organic carbon (SOC) and salinity as affected by continuous MDI is still unclear. In this study, we examined four MDI ages (9, 13, 15, and 23 years) of cotton fields that were converted from wasteland (CK, 0 year) and evaluated the impact of MDI age on soil aggregate size distribution, aggregate stability, and aggregate-associated SOC/salinity. The results showed that the proportion of macro-aggregates (>0.25 mm) and aggregate stability (MWD, GMD) initially decreased and then increased as MDI age progressed. As MDI age increased, the concentration of aggregate-associated SOC in all fractions significantly increased, while salt concentration significantly declined. Compared to the CK (0 year), the total SOC stock in cotton fields aged 9, 13, 15 and 23 years increased by −0%, 11%, 17%, and 87%, respectively; whereas the total salt stock decreased by 33%, 68%, 67%, and 76%, respectively. Moreover, due to the significant increase in macro-aggregate content and associated SOC concentration with MDI age, the storage of SOC in older MDI ages (15–23 years) was more reliant on macro-aggregates. Pearson correlation and principal component analysis indicated a negative correlation between salinity and macro-aggregates, aggregate stability, and SOC, while there was a positive correlation among MDI age, SOC, macro-aggregates, and aggregate stability. Based on our findings, we concluded that long-term MDI promotes the formation of macro-aggregates, enhances aggregate stability by reducing soil salinity and increasing SOC stock. • Long-term MDI strongly affects soil aggregate characteristics. • Long-term MDI significantly increased SOC stock and decreased soil salt stock. • SOC and salinity are key factors affecting macro-aggregates formation under MDI. • SOC storage is primarily dependent on macro-aggregates under long-term MDI. [ABSTRACT FROM AUTHOR]

Advancements in mulching drip irrigation for cotton cultivation have led to changes in plastic film width in Xinjiang, China. Concurrently, the application of brackish water for irrigation is increasingly becoming a common practice in areas where freshwater resources are limited. The effects of varying film widths and the salinity levels of irrigation water on soil hydrothermal properties, cotton growth, and yield are comprehensively investigated. A field experiment was carried out over two years (2021−2022) in Xinjiang, China. It involved testing three film widths (F1: ultra-wide film, 4.45 m; F2: wide film; 2.05 m, F3: narrow film; 1.45 m) and three levels of irrigation salinity (S1: 1 g L−1, S2: 3 g L−1, S3: 5 g L−1). Wider film widths significantly increased soil water storage (SWS) and accumulated active temperature (SAT). Compared to F3, the SAT for F1 increased by 14.6−15.7 % in 2021 and by 14.1−15.8 % in 2022, respectively. Furthermore, increasing film width was found to promote cotton growth, enhance the photosynthetic capacity, and increase cotton yield by 19.2−24.1 % in 2021 and by 17.4−23.3 % in 2022, respectively. Importantly, irrigation water with a salinity level of 3 g L−1 had no adverse effect on cotton growth and development. However, an irrigation water salinity of 5 g L−1 significantly reduced cotton yield. The highest seed cotton yield and water use efficiency were observed under the S2F1 treatment, recording 5876 kg ha−1 and 11.55 kg ha−1 mm−1 in 2021, and 5905 kg ha−1 and 11.58 kg ha−1 mm−1 in 2022, respectively. Additionally, a structural equation model was developed to explore the interrelationships between the soil hydrothermal environment, cotton growth, photosynthetic capacity, and seed cotton yield. The findings highlight the benefits of using ultra-wide film (4.45 m) in conjunction with irrigation water having a salinity level of up to 3 g L−1. This combination significantly improves cotton yield and water use efficiency, showcasing a promising approach for sustainable cotton cultivation in semi-arid regions. • Ultra-wide film mulching improves soil hydrothermal conditions. • Irrigation water with a salinity < 3 g L–1 does not adversely affect cotton growth. • Using ultra-wide film and saline water of 3 g L–1 increases cotton yield and WUE. [ABSTRACT FROM AUTHOR]

Biodegradable film (BF), as a superior substitute for traditional polyethylene film (PF), has experienced a consistent increase in China. However, a significant research gap persists regarding the utilization of BF in assessing farmland carbon balance. This experiment examined the responses of maize growth, yield, irrigation water productivity (IWP), CO 2 emissions, and field net carbon sequestration (NCS) to two BF types (BF 1 , 100-day induction period, and BF 2 , 80-day induction period), and PF, and three irrigation amounts (I 1 , I 2 , I 3 : 5250, 5625, and 6000 m3 ha–1), by conducting a two-year (2019–2020) field trial in a typical arid and semi-arid region of China. The results indicated that biodegradable film mulching (BFM) negatively affected maize growth, resulting in reduced yield and IWP. Especially under the I 1 irrigation level, the biodegradable film reduced maize yield by 6.26%–13.99% and IWP by 6.64–13.85%. Notably, in the I 2 irrigation level, BF 1 mulching had a comparable impact on maize yield and IWP to that of PF. Additionally, the increase in irrigation amounts exerted a more pronounced promoting effect on maize total biomass than on yield and IWP. Concerning carbon balance, short-term BF application resulted in reduced CO 2 emissions (5.74–6.30% under BF 1 and 9.27–12.37% under BF 2), without any significant impact on NCS in cropland. Taking into account the economic value of maize and farmland ecology, we recommended utilizing irrigation amounts of 5625 m3 ha–1 for BF application in arid areas, while opting for a BF with a longer induction period whenever feasible. • Biodegradable film mulching reduces maize yield and irrigation water productivity. • Biodegradable film mulching significantly decreases soil CO 2 emissions. • Increasing irrigation compensates for yield loss due to biodegradable film mulching. • Biodegradable film with a 100-day induction period is an ideal covering material. [ABSTRACT FROM AUTHOR]

The employment of brackish water for irrigation holds considerable potential for addressing the shortfall of freshwater resources in arid regions. It is crucial to discern the impact of salinity on agricultural output and its mechanisms when irrigating with brackish water. Here, a two-year field experiment (2021–2022) was undertaken in Xinjiang, China to assess the effects of water salinity (0.85 g L−1, CK; 3 g L−1, S1; 5 g L−1, S2; and 8 g L−1, S3) on the growth, photosynthesis, carbon accumulation, and cotton yield under mulched drip irrigation. Results showed that, compared to CK, the S1 treatment led to increased biomass, the boll capacity of the root system (BCR), and a reduced root-to-shoot ratio (R/S). In addition, the S1 treatment enhanced the net photosynthetic rate (Pn) and chlorophyll content (Chl) of cotton, enhancing the total carbon accumulation of boll (C boll) and consequently, the seed cotton yield. However, the higher salinity treatments, S2 and S3, demonstrated a detrimental impact on these indicators. In comparison to CK, the S1 treatment showed a yield increase of 5.92% and 4.76% in the respective two years, yet the S2 and S3 treatments showed a yield decrease of 5.55–15.77% and 5.06–16.74%. The application of a structural equation model (SEM) elucidated a direct effect of photosynthetic parameters (Pn and Chl) and biomass characteristics (total biomass, R/S, and BCR) on yield. These factors also indirectly modulated seed cotton yield through the C boll /C root ratio. These results suggest that irrigation with brackish water of 3 g L−1 optimizes cotton production by coordinating crop growth of aboveground and underground parts. This study offers practical strategies for the cotton industry to enhance yields under brackish water irrigation. • Irrigation water with salinity levels of 3 g L−1 facilitates cotton growth. • Interactions between cotton growth, photosynthesis, and yield were examined. • Irrigation water with salinity levels of 3 g L−1 can be used in cotton industry. [ABSTRACT FROM AUTHOR]

In the agricultural zones of the arid Xinjiang region of China, reducing irrigation is mandatory. However, irrigation affects the composition and diversity of the soil bacterial community which is vital to crop yield. To the best of our knowledge, very little research has been conducted on the relationships among the soil bacterial community, irrigation method, and yield as well as their underlying in jujube agroecosystems. Here, we investigated the soil physicochemistry and bacterial communities in jujube fields subjected to drip irrigation (DI) and traditional flood irrigation (FI), and their associations with yield at the flowering and fruit set (FFS) and end-of-growth (EG) stages. Under DI, the jujube yield was 8712.00 ± 24.54 kg/hm2, which was 7.64% higher than that obtained under FI (8094.33 ± 43.67 kg/hm2). DI increased the relative soil bacteria community diversity by decreasing the moisture content and increasing the nutrient levels in the soil. DI also transformed the soil bacterial community so that Bacteroidota predominated at the FFS stage and the probiotics Chloroflexi and Firmicutes predominated at the EG stage. A co-occurrence network analysis showed that DI created stable complex Soil bacteria communities in jujube fields, Though Dependentiae and Deferriberota had low relative abundance, they were nonetheless key nodes in the soil bacterial community network. A neutral community model (NCM) revealed that stochastic processes drove the soil bacterial community assembly whereas DI promoted deterministic processes by regulating the soil moisture content and nutrient levels. Partial least squares path modeling (PLS-PM) disclosed that DI affected the soil bacterial community structure by decreasing the moisture content (−0.342 **) and increasing the nutrient levels (0.557 **) in the soil. The PLS-PM also demonstrated that the observed change in the soil bacterial community structure was the main reason for the increase in jujube yield (1.098 **). The present work provides insights into the mechanisms underlying the correlations between the soil bacterial community and crop yield in response to changes in the irrigation method. • Drip irrigation regulates the levels of soil moisture and nutrients. • Drip irrigation of soil moisture and nutrients drive the transformation of Bacteroidota to Chloroflexi and Firmicutes. • Dependentiae and Deferriberota with low relative abundance also the key species. • DI induced a small decrease in stochastic assembly for soil bacterial community. • DI increased the jujube yield (8712 kg/hm2) mainly by bacterial composition. [ABSTRACT FROM AUTHOR]

Utilizing brackish water with drip irrigation technology, due to its precise water control alleviates the secondary soil salinization, and improves crop yield and quality, which offers sustainable agricultural development opportunities in saline areas. However, the complex characteristics of brackish water increase the risk of drip irrigation emitter clogging, which inhibit its promotion and adoption. It is necessary to find out the dominant water quality ions that lead to emitter clogging under multiple ion interactions when using brackish water under multiple ion coexistence conditions. Thus, the in-situ pilot research was conducted to study the emitter clogging mechanism using brackish water collected from 16 different salt-alkaline regions. A comprehensive evaluation with the consideration of 11 water quality ions on emitter clogging were conducted. Results showed that the degree of emitter clogging gradually increased in the first 40 days of irrigation, hereafter started an accelerated reduction until the days 64 of brackish water application. Spearman correlation and structural equation modelling were used to identify the main factors contribute to emitter clogging. And results indicated that calcium fouling (CF) and silica fouling (SF) were the major fouling minerals in the emitter flow channels. Ca2+, CO 3 2-+HCO 3 -, pH, total hardness (TH), and zeta potential (ZP) were the key water characteristics leading to emitter clogging. These factors directly affected CF and SF, while also affecting the Mg2+, Mn2+, Cu2+, and other water quality factors which indirectly enhanced the CF and SF. Thereafter a few water quality control strategies were proposed based on emitter clogging and soil salinization mitigation. This study identified the key water quality ions that induce drip irrigation emitter clogging when using brackish water, provided solid support for solving the clogging issue, and promoted the high-efficient utilization of brackish water in saline areas. • Brackish water drip irrigation performance in saline areas was studied. • Main types and formation of fouling in drip irrigation systems were analyzed. • Critical water quality ions for brackish water utilization were identified. • Control strategies considering irrigation and soil environment were proposed. [ABSTRACT FROM AUTHOR]

Residual plastic pollution in terrestrial soils has emerged as a globally significant environmental challenge on a global scale, particularly in agricultural systems. Within extensive areas of plastic film-covered agriculture, the presence of residual macro-plastic debris (> 0.5 cm) has resulted in immeasurable losses to soil quality and crop production. To date, there is a lack of research investigating the potential impact of plastic mulching film residues on soil properties, crop yield, and the quality of cotton fiber. In this study, a field experiment was conducted for the first time to assess the effects of different amounts of residual plastic film (RPF) on soil hydrothermal characteristics, cotton growth, and fiber quality in drip-irrigated cotton fields. The experiment encompassed six amounts: RPF 0 (0 kg ha−1), RPF 5 (146.18 kg ha−1), RPF 10 (228.03 kg ha−1), RPF 15 (309.88 kg ha−1), RPF 20 (391.73 kg ha−1), and RPF 25 (473.58 kg ha−1). The trial spanned the period from 2020 to 2021. The elevation in the amount of RPF had a positive impact on irrigation water storage in the soil and resulted in decreased water consumption by cotton plants. Concurrently, it led to an increase in the average soil temperature and the accumulated active temperature in the 0–25 cm soil layer. However, there was a notable rise in the interannual levels of nitrate nitrogen in the soil with the augmentation of RPF. In addition, the abundance of macro-plastic debris in the soil correspondingly suppressed cotton fiber quality. To ascertain the effect of plastic film residue on soil properties, cotton economic benefits, and fiber quality, a structural equation model was developed. It is imperative to promptly adopt environmentally friendly agricultural mulch materials in order to minimize the input of macro-plastic debris and enhance the recycling of native soil plastic film residues. • Macro-plastic debris reduces the efficiency of irrigation water use in cotton. • High abundance of residual plastic film increases the risk of soil nitrate-N leaching. • Plastic film residue significantly limits the cotton field's economic benefits. • Cotton fiber quality can be weakened by soil residual macro-plastic debris. [ABSTRACT FROM AUTHOR]

Soil nutrients and enzymes are essential indicators of ecological functions in terrestrial ecosystem and are also sensitive to land-use change. However, the response of soil nutrients and enzymes to long-term mulched drip irrigation (MDI) in the conversion of agroecosystems is still limited. In this study, we analyzed soil nutrient concentrations and enzyme activities at a soil depth of 0–40 cm in four typical cotton fields with different durations of MDI (8, 12, 16, and 22 years) and a wasteland (CK) as control. After the conversion of saline-alkali wasteland into cotton fields, we found that soil electrical conductivity (EC) and pH significantly decreased, but the concentrations of available soil phosphorus (AP), total carbon (TC), soil organic carbon (SOC) and total nitrogen (TN) significantly increased with increasing years of MDI application. Soil enzymes, such as polyphenol oxidase, catalase, urease, alkaline phosphatase, and cellulase were more active in the subsoil than in the topsoil. Compared to the wasteland, a significant reduction of soil enzyme activities (polyphenol oxidase, catalase, and cellulase) appeared in the young cotton field, which gradually reestablished after practicing long-term MDI. Based on redundancy analysis, the variations of the enzyme activities were obtained by pH (38.7 %), C/N (27.6 %), EC (20.9 %), TN (4.9 %), and NO 3 −-N (3.1 %) at 0–20 cm depth; and by AP (43.7 %), SWC (18.4 %), pH (12.6 %), and TN (12.5 %) at 20–40 cm depth. Long-term MDI has a positive effect on reducing soil salinity, increasing nutrient content in cotton fields, and can accelerate the activities of nutrient-releasing enzymes, which partly confirm the sustainability of MDI in oasis agroecosystems. • Converting wasteland to cropland strongly stimulates soil enzyme activity. • Long-term MDI after wasteland conversion decreases soil salinity and alkalinity. • Long-term MDI tends to accumulate soil nutrients and rebuild enzyme conditions. [ABSTRACT FROM AUTHOR]

In order to harness the ample solar energy resources and minimize conflicts in drip irrigation schedules, a field experiment was conducted in Xinjiang, northwest China, during 2020 and 2021. The study examined the combined effects of two irrigation timing (daytime - DI and nighttime - NI) and four water temperatures (15, 20, 25, and 30 °C), resulting in eight treatment combinations. The analysis focused on evaluating the impacts of these factors on soil conditions, cotton phenological period, reproductive growth, and fiber quality. Results showed that elevating the irrigation water temperature had a notable impact on soil respiration throughout the different growth stages. The treatment with an irrigation water temperature of 30 °C exhibited a substantial increase in soil respiration, ranging from 17.92% to 45.95%, when compared to conventional irrigation with water temperature at 15 °C. The elevation of irrigation water temperature resulted in notable reductions in soil nitrate and ammonium nitrogen levels. Specifically, the treatment with irrigation water temperature set at 30 °C exhibited an average decrease of 21.69% and 19.27% in soil nitrate and ammonium nitrogen content, respectively, compared to the 15 °C treatment in both years. Nighttime irrigation with increased water temperatures of 20, 25, and 30 °C advanced the onset of the boll opening stage and stimulated the reproductive growth of cotton. Conversely, irrigation with regular water temperature (15 °C) decreased the number of bolls during the early boll-forming period, as well as and the peak number of squares and flowers. However, it resulted in an increased number of bolls during the late boll-forming period. Surprisingly, despite the enhancement in fiber strength and elongation due to water-warming irrigation, it unexpectedly led to a decrease in fiber length and uniformity. Moreover, higher irrigation water temperatures (25 and 30 °C) even resulted in poor levels (> 5.0) of micronaire. Nevertheless, nighttime warming irrigation improved all other fiber qualities except for uniformity. Therefore, when considering the application of water-warming irrigation in arid regions under mulched drip systems, careful selection of irrigation timing and water temperatures is necessary, taking into account the desired fiber quality. This study serves as a valuable technical reference for such irrigation practices. • Water warming promote soil respiration and nitrogen consumption. • Water temperature and irrigation timing significantly affect cotton phenology. • Water warming decreases the fiber quality of cotton. [ABSTRACT FROM AUTHOR]

Soil microorganisms are key drivers of soil nutrient cycling and agroecosystem sustainability. Despite their critical roles in soil evolution processes, the variation of soil microbial communities in cotton fields with different years of practicing mulched drip irrigation remains poorly understood. The objectives of this study were to investigate the effects of different years of mulched drip irrigation (i.e., CK, 11, 13, 15, and 21 years) on soil microbial communities and soil properties in cotton fields in an oasis by using high-throughput sequencing of the microbial 16 S/ITS gene. The results showed that soil EC decreased significantly after mulched drip irrigation and the lowest value occurred in 21-year treatment, decreased by 74.43%. Soil organic carbon, available nitrogen, available phosphorus and available potassium increased significantly with the length of years under mulched drip irrigation. The abundance of dominated bacterial phyla (Actinobacteria , Bacteroidetes, and Rokubacteria) significantly varied among different years of mulched drip irrigation, and no significant change was found in soil fungal community at the phyla level. The abundance of dominated fungal genera Cephalotrichum (21.82–68.96%) decreased significantly with irrigation years extension. Non-metric multidimensional scale analyses (NMDS) showed that soil bacterial and fungal communities significantly differed among different treatments (P = 0.001). The more positive co-occurrence relationships of bacteria to fungi, and the highest Shannon and lowest Simpson values were observed in the 13-year mulched drip irrigation. The abundance of bacteria and fungi was significantly correlated with soil EC, total nitrogen, total potassium, and soil organic carbon. Our results indicated that long-term mulched drip irrigation affected the structures and interactions of microbial communities in cotton fields by reducing soil salinity and regulating the soil nutrient concentrations, and 13-year mulched drip irrigation was capable of enhancing soil microbial diversity in this region. • Applying time of mulched drip irrigation significantly affected the soil bacterial and fungal communities characteristics. • 13-year mulched drip irrigation improves not only soil fertility but also soil microbial diversity in arid oasis regions. • The long-term mulched drip irrigation affected the microbial communities by changing soil salinity and nutrient concentrations. [ABSTRACT FROM AUTHOR]

Mulched drip irrigation is the primary irrigation technology for cotton (Gossypium hirsutum L.) cultivation in arid and semi-arid regions. In recent years, the increasing amount of residual plastic film (RPF) in mulched cotton fields has posed a more significant threat to soil quality and the sustainability of agricultural production. However, the relationship between different soil RPF amounts and cotton growth, yield, and carbon balance in cotton fields is unclear. In this study, six RPF amounts, namely RPF 0 (0 kg ha–1), RPF 5 (146.18 kg ha–1), RPF 10 (228.03 kg ha–1), RPF 15 (309.88 kg ha–1), RPF 20 (391.73 kg ha–1), and RPF 25 (473.58 kg ha–1), were set in a two-year (2020–2021) field experiment to investigate their effects on cotton growth, yield, field CO 2 emissions, and carbon sequestration. Results showed that cotton growth indicators (Plant height, stem diameter, leaf area index, biomass of each organ) at different growth stages and yield indicators (Single boll weight, per plant bolls number, seed cotton yield) were significantly negatively correlated (p < 0.05) with the soil RPF amount. The RPF 25 treatment showed yield decreases of up to 33.4% and 43.2% in these two years, respectively, compared with the RPF 0 treatment. Surprisingly, the presence of RPF in soil reduced the rate and cumulative CO 2 emissions from cotton fields during the growth and fallow periods, but carbon sequestration in cotton fields decreased significantly with increasing RPF amounts (15.05%~60.98% in 2020 and 17.38~76.81% in 2021). RPF inhibited cotton root growth, reducing plant biomass accumulation, decreasing seed cotton yield, and weakening cotton fields' carbon sink. When the RPF amount in the soil was less than or equal to 228.03 kg ha–1, cotton economic benefits and field carbon storage were not unduly weakened. The second-year indicators of cotton fields with the RPF were significantly lower than the first year, and the permanent residue of soil RPF also created a more hostile crop growing environment. We concluded that the RPF amount in fields should be reduced as soon as possible and that more environmentally friendly and carbon-reducing mulching materials should be used instead of plastic film. • Residual plastic film has a negative impact on cotton growth and biomass accumulation. • Residual plastic film affects yield composition and carbon balance between different years. • Plastic film residues reduce yield and weaken carbon sink of cotton fields. [ABSTRACT FROM AUTHOR]

Brackish water drip irrigation (BWDI) is an effective application to overcome the water scarcity issues and achieve sustainable agriculture development. However, emitter clogging and soil salinization is inevitable issue in BWDI, eventually threatening the environmental pollution and sustainable application of drip irrigation systems. Therefore, this study experimentally assessed the anti-clogging efficacy of compounding appropriate types of humic acid (HA) with conventional fertilizer in BWDI systems (BWDIs). Humic acid nitrogen (HAN), humic acid phosphate (HAP), humic acid potassium (HAK), were compounded with conventional fertilizers. Our results revealed, compared with conventional fertilizer (CK) the HA treatments indirectly affected the precipitates and particulate fouling by absorbing the active functional groups, and directly decreased the pH, calcium and magnesium contents in brackish irrigation water. Accordingly, HA compound fertilizer significantly reduced the fouling content of drip irrigation system, and the anti-clogging effect became better with the increase of HA application. Thus, based on better anti-clogging performance and minimum fertilizer costs, our results suggested, the HAN+HAK integrated fertigation could be an effective selection for BWDIs, which significantly enhanced the average discharge ratio and Christiansen coefficient of nutrient uniformity in BWDIs by 16.0% and 19.0% respectively. These results might provide a new guideline for the successful application of HA compound fertilizer in BWDIs, to increase the drip irrigation anti-clogging ability and overcome the agricultural non-point source pollution issues. • Effects of humic acid compound fertilizer on fouling of drip irrigation systems were analyzed. • Humic acid compound fertilizer reduced the precipitate and particulate fouling. • Compound fertilizer HAN+HAK are recommended in brackish water drip irrigation. [ABSTRACT FROM AUTHOR]

Water scarcity and deficiency of trace elements (e.g., Cu and Mn) in soils of arid and semi-arid areas are major constrains to crop growth and development. The application of brackish water drip irrigation system (BWDIs), coupled with trace elements, is probably an effective way to solve this problem. However, fouling problems caused by trace elements in BWDIs were inevitable. Therefore, this paper evaluates the mechanism of different types of trace element chelated fertilizers on the fouling of emitters in BWDIs by using long-period, high-frequency periodic flow monitoring and mineral fraction analysis. The influence of chelated fertilizers such as copper (EDTA-Cu) and manganese (EDTA-Mn), and traditional micro-fertilizers copper sulfate (CuSO 4) and manganese sulfate (MnSO 4) on emitter fouling in BWDIs were investigated. Results suggested, compared with CK, the EDTA-Cu effectively alleviated the emitter fouling, increasing the average discharge ratio (Dra) and Christiansen coefficient of uniformity (CU) by 21.0%− 28.9% and 36.7%− 67.6%, respectively. Due to the strong adsorption ability, EDTA-Cu adsorb the Ca2+ and Mg2+ in BWDIs, which enhanced the structural stability, reduced the flocculation and deposition ability in the fouling, and indirectly reduced the content of calcium and silica fouling. In addition, compared with CK, the EDTA-Mn significantly aggravated the emitter fouling in BWDIs, decreasing the Dra and CU by 18.2%− 22.5% and 24.5%− 43.1% respectively. EDTA-Mn directly increased the content of Ca2+ and Mg2+ in BWDIs due to strong flocculation, which destroyed the morphology of EDTA-Mn chelates and indirectly increased the content of calcium silica fouling (calcite, muscovite, k-feldspar, dolomite and chlorite), thus reduced the anti-clogging ability of BWDIs. Considering these results, this study does not recommend the application of EDTA-Mn for manganese fertilizer in BWDIs. This study provides a new perspective on the rapid application of micronutrient fertilization in BWDIs, with potential implications for sustainable development in arid and semi-arid areas. • Effect of manganese and copper fertilizers on fouling of drip irrigation systems was analyzed. • EDTA-Cu fertilizer significantly reduced calcium and silicate fouling in the irrigator runners. • Use of EDTA-Cu fertilizer in brackish water drip irrigation is strongly recommended. [ABSTRACT FROM AUTHOR]

Cultivation after converting saline and alkaline wasteland to agricultural land is usually accompanied by accelerated soil salinization. There is general agreement that freezing-thawing process plays a crucial role in soil salinization in mostly cold-arid agricultural areas, which leads to the impoverishment of soil productivity. To investigate the migration characteristics of soil salinity in saline-sodic cotton field with different reclamation time in non-irrigation season, we examined the soil bulk, total porosity, and spatial and temporal migration of soil salinity in winter in an oasis agroecosystem of northern Xinjiang, China. Experimental plots include a saline-alkali wasteland as control and cotton fields under four age categories (cultivation start years were 1998, 2006, 2008, and 2012, respectively). The results showed that converting saline-alkali wasteland to cotton land significantly decreased soil bulk density but increased total soil porosity, especially at 0–40 cm. Conversion significantly decreased soil salinity at 0–200 cm soil depths, with a greater decrease in cotton land after relatively longer time of cultivation. After freezing-thawing process, soil bulk density decreased 4.87% on average, and total porosity increased 5.98%. Soil salt dynamics showed that there were two stages in salt accumulation. Firstly, soil salt storage increased at 0–100 cm depth but decreased at 100–200 cm depth during freezing period; Secondly, rapid increase of salt storage appeared at late thawing period. In addition, salt accumulation positively correlated to initial salt content and bulk density, but negatively correlated to total porosity. At springtime, cotton land with short-term cultivation was desalination comparing with pre-freezing, but salt accumulation occurred after long-term cultivation. These results highlighted that long-term cultivation with mulched drip irrigation decreased soil salinity in the 0–200 cm soil profiles, but freezing-thawing process induced soil salinization which poses a potential risk to agricultural sustainability. • Converting wasteland to farmland decreased soil bulk density and increased total porosity. • Long-term cotton cultivations with drip irrigation significantly decreased soil salinity. • Freezing-thawing action decreased soil bulk density and increased total porosity. • Freezing-thawing action poses a potential risk to agricultural sustainability. [ABSTRACT FROM AUTHOR]