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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]

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]

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]

In some arid regions, the complex planting environment creates higher requirements in terms of cotton planting field management. In order to make a reasonable strategy to utilize underground saltwater resources, save irrigation water and reduce the excessive application of nitrogen fertilizer, we carried out a field experiment in Xinjiang. This study is conducted to explore the effects of irrigation water quantity, irrigation water salinity, and nitrogen application rate on nitrogen fertilizer absorption and cotton yield. Here, three experimental factors and four levels were used in the experiment. Irrigation amounts: 0.7, 1.0, 1.3 and 1.6 ETc; irrigation water salinity: 10.9, 7.8, 4.7, 1.5 dS m−1; nitrogen application: 100, 200, 300 and 400 kg N ha−1 were set in the experiment. The experiment was designed according to orthogonal table L 16 (43). The results showed that the salinity of irrigation water had no effect on soil nitrogen transport, and the soil nitrogen content increased with the increase in nitrogen application. A low level of irrigation increased the lateral migration of nitrogen, whereas excessive irrigation increased the migration of nitrogen to deep soil. When the ratio of irrigation amount (mm) and nitrogen application (kg N ha−1) was 2.77, it could ensure the uniform distribution of nitrate nitrogen, and made nitrogen accumulate in the soil layer around the crop root zone. High irrigation increased the nitrogen uptake of the whole cotton plant; however, excessive irrigation would cause the apical dominance of cotton, such that the accumulation of dry matter and nitrogen migration were mainly concentrated in cotton roots and stems, which was not conducive to the migration of nitrogen to the boll (boll shell, seed and fiber). The combination of 675 mm, 7.8 dS m−1, and 400 kg N ha−1 was more conducive to the migration of nitrogen to the cotton boll. Through principal component analysis, 675 mm irrigation amount, 1.5dS m−1, and 200 kg N ha−1 is the most recommended irrigation and fertilization strategy. When the irrigation water salinity drops to 7.8 dS m−1, salt stress can be alleviated by increasing the nitrogen application to 400 kg N ha−1. [Display omitted] • The interaction of irrigation amount and nitrogen application rate greatly affected the soil nitrate nitrogen content. • The ratio of irrigation amount (mm) and N application (kg N ha−1) of 2.77 can ensure the uniform distribution of nitrate-N. • Excessive irrigation will cause the apical dominance of cotton and also can decrease productivity. • A combination of 675 mm, 7.8 dS m−1, and 400 kg N ha−1 was found more favorable for the migration of N to the cotton boll. [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]

Due to their convenience, water measuring structures have become an important means of measuring water in irrigation canal systems However, relevant research on upstream and downstream water-depth monitoring point locations is scarce. Our study aims to determine the functional relationship between the locations of the water-depth monitoring points and the opening width of the sluice. We established 14 trunk-channel and branch-channel hydrodynamic models. The locations of the water-depth monitoring points for the upstream and downstream reaches and their hydraulic characteristics were assessed using a numerical simulation and hydraulic test. The results showed that the locations of the upstream and downstream water-depth monitoring points were, respectively, 16.26 and 15.51 times the width of the sluice. The average error between the calculated flow rate and the simulated value was 14.37%; the average error between the flow rates calculated by the modified and the simulated values was 3.36%. To further verify the accuracy of the modified discharge calculation formula, by comparing the measured values, we reduced the average error of the modified formula by 19.29% compared with the standard formula. This research provides new insights into optimizing water measurements in irrigation canal systems. The results provide an engineering basis for the site selection of water-depth monitoring points that is suitable to be widely applied in the field. [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]

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]

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 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]

In the Yellow River Delta, soil salinization and river sediment are the two factors influence on economic growth. A large area of salinization reduces crop yields and dredged river sediment increases management costs. This study evaluated the effects of applying sediments under different levels of irrigation on salinity leaching for improving field productivity. A three-year field experiment (from June 2017 to June 2020) was conducted by considering three levels of sediment application:a control (no sediment added, S1), 30▒mm ha−1 (S2) and 60▒mm ha−1 (S3), and three levels of irrigation water: 290▒mm (90▒mm maize + 200▒mm wheat, W1), 385▒mm (120▒mm maize + 265▒mm wheat, W2) and 480▒mm (150▒mm maize + 330▒mm wheat, W3). The results exhibited that soil leaching rate was up to 66.3 % under 60▒mm ha−1 sediment application and 385▒mm irrigation after three wheat-maize rotation cultivation. This irrigation and sediment applied strategy achieved the effect of leaching salt, saving water and increasing grain yields. The mean yield of wheat and maize in sediment application and irrigation treatment was 18.3▒t ha−1 in three-year experiment which was significant bigger than the control. Thus, it is a technically feasible and friendly sustainable approach for salinization soil development in the Yellow River Delta. • Coupling effects of irrigation and sediment application on soil physical properties and grain yield. • Response of soil salinity to sediment application improves understanding of underlying mechanisms involved. • Sediment application at a rate of 60▒mm ha−1 was optimal to enhance grain yield. [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]