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Establishing lucerne field is an efficient way to protect natural steppes, alleviate conflicts between meadows and livestock, and promote the development of animal husbandry. However, problems such as extensive field management, valuing yield over quality, and low resource utilization are endemic in production. Exploring reasonable cultivation patterns can contribute to improving the current situation of artificial grassland production and promoting the high-quality development of husbandry and prataculture. Lucerne the field experiment was carried out in Jingtai, Gansu Province, China in 2021–2022; this study compared and analyzed the effects of three cultivation patterns—ridge tillage with plastic film mulching (PM), ridge tillage with biodegradable film mulching (BM), and traditional flat planting (FP)—on soil water, heat, and fertilizer, as well as lucerne growth, yield, quality, and water and nitrogen use efficiency. The results show that: (1) during the growth period of lucerne, PM and BM treatments augment the average moisture content of the soil layer of 0–120 cm by 31.19% and 24.03% compared to the FP treatment, respectively. In the soil layer of 0–40 cm, PM and BM treatments abate the soil moisture content of the ridges by an average of 19.29% and 7.89% compared to that in the ditches, respectively. In the soil layer of 40–120 cm, PM and BM treatments elevate the soil moisture content of the ridges by 4.40% and 4.65% on average compared to that in the ditches, respectively. The average soil temperature in a soil layer of 5–25 cm shows PM > BM > FP. In contrast with the FP treatment, PM and BM treatments increase the soil temperature of the ridges by an average of 1.87 °C and 0.96 °C and decrease that of the ditches by an average of 0.47 °C and 0.46 °C, respectively. After two years of planting, the three cultivation patterns all promote the soil nutrient content. Compared to the FP treatment, PM and BM treatments increase the organic matter content by 9.94% and 19.94%, respectively. (2) Ridge tillage with film mulching can evidently stimulate the growth of lucerne and enhance yield and quality. Compared to the FP treatment, PM and BM treatments enhance plant height by an average of 15.37% and 4.04%, stem diameter by an average of 34.14% and 14.58%, yield by an average of 21.20% and 14.77%, crude protein content by an average of 13.47% and 7.68%, and relative feed value by an average of 8.71% and 4.41%, respectively. (3) During the two-year growing period, the irrigation amount of lucerne was 508.60–615.30 mm, and the evapotranspiration was 563.70–761.80 mm. Compared to the FP treatment, PM and BM treatments hoist water use efficiency by an average of 43.50% and 17.56%, nitrogen partial factor productivity by an average of 21.20% and 15.22%, and net income by an average of 14.78% and 11.05%, respectively. In summary, in ridge tillage, both ordinary film mulching and biodegradable film mulching can create a favorable soil environment for lucerne growth and heighten production effect. The former has a better effect on advancing the lucerne production effect, and the latter exhibits superior performance in improving soil fertility. [ABSTRACT FROM AUTHOR]

Crop residue returning (CRR) is known to improve the soil environment and thus increase crop production. However, the impacts of CRR on wheat (Triticum aestivum L.) yield have been contrary at times due to the differences in climatic conditions, soil traits, and management practices. These effects were evaluated using 351 paired observations published in 161 papers comprising studies conducted in 19 provinces (autonomous regions) of China. No publication bias or extreme values were found in the data, indicating that the analysis results are highly reliable. Compared with the practice of no crop residue returning (NCRR), the practice of CRR increased wheat yield significantly, on average by 8.29%, and proved more beneficial in Northwest China and in regions with average annual precipitation of 200 to 400 mm, average annual temperatures >11°C, sandy loam soil, and rotation with legumes (soybean [Glycine max (L.) Merr.]–wheat and pea [Pisum sativum L.]–wheat). The following aspects of CRR and crop management conferred greater benefits in yield: continuing the practice for 3 to 6 yr (compared with 1–2, 7–10, and ≥11 yr), using the residues at 3 to 6 t ha−1 (compared with <3, 6–9, and > 9 t ha−1), chopped straw (compared with intact straw), rainfed conditions (compared with irrigated conditions), and applying N at 200 to 300 kg ha−1 (compared with <100, 100–200, and >300 kg ha−1). The yield increase was significantly higher when the residues were returned in the form of mulch (12.56%) and for spring wheat (11.90%) than plowing them back into soil (4.53%) and for winter wheat (7.09%). The meta‐analysis thus confirms the benefits of CRR in higher wheat yields in China and also suggests that the benefits of CRR are site specific. [ABSTRACT FROM AUTHOR]

Characteristics of temporal-spatial potential evapotranspiration (ET0) distribution in Gansu Province were studied based on the Cloud model, which is a mathematical representation of qualitative concepts including expected value Ex, entropy En and hyper entropy He, integrates the fuzziness and randomness of qualitative concept in a unified way, and is a new method for the transformation between the qualitative and the quantitative. The values of ET0 were calculated by Penman-Monteith. The changes of ET0 in time were analyzed at monthly, seasonal and yearly intervals, respectively, and spatial changes were mainly divided into 4 parts: Hexi area, the middle, east and south area of Gansu. All data of 63 years (1951-2013) were collected at 29 meteorological stations involving the above districts in Gansu. All ET0 data were achieved by the soft Interactive data language. The indices of homogeneity and stability were used for reflecting characteristics of temporal-spatial distribution of ET0, which were achieved by Cloud mode, solving the uncertain conversion of qualitative concept and quantitative description. And the changes of ET0 in time (monthly, seaonal and annual) and space were analyzed by the linear change and the contour image. The results showed annual variation in ET0 had a fluctuation and increasing tendency, and the tendency rate was 2.11 mm/(10a) in all study area (P<0.05). The monthly change curve of ET0 for 63 years was single apex type, which was: ET0 in June and July was higher than that in other months. In homogeneity and stability aspects of ET0, from November to March of the next year was better than from April to August in the same year. At the same time, there was significant difference on the distribution of ET0 among seasons, and the maximum was summer, followed by spring, and the least was autumn and winter. The further analysis found that both homogeneity and stability of temporal-spatial distribution of ET0 had no consistency among seasons. The homogeneity of ET0 in autumn and winter was higher than that in spring and summer, but the stability in summer and autumn was better than that in spring and winter. Seen from the difference characteristics of the space, ET0 in the northwest area of Gansu Province were larger than that in the southeast, however, the annual changes of ET0 among areas were different for 63 years. Concretely speaking, the value of annual ET0 in Hexi area was keeping the highest from 1951 to 2013. Seeing the changes of ET0 in the space using the homogeneity and stability, we found ET0 of Hexi area was most discrete and instable, the east area of Gansu had the best homogeneity and stability, and the middle and south were between them. The homogeneity and stability of ET0 in the space was worse than that in the time. Generally, the homogeneity of the distribution of ET0 was increasing since 1981, namely, the homogeneity from 1981 to 2013 was better than that from 1951 to 1981, and at the same time, the stability was also increasing for 63 years. [ABSTRACT FROM AUTHOR]

Chinese Farming-pastoral Ecotones (CFPE) is the largest ecologically fragile zone in China. The dynamic prediction and impact factors analysis of landscape ecological risk based on LUCC have an important significance for effectively resolving ecological and environmental risk. In this paper, CA-Markov and BRT models were used to quantitatively analyze dynamic change, evolution characteristics, and influencing factors of landscape ecological risk.The results showed that: (1) LUCC types significantly changed from 2000 to 2040, especially in the bareland regions, which decreased by 1.64 times from 2000 to 2020, mainly transferred out to grassland and farmland. (2) The overall ecological risk showed a trend of increasing first and then decreasing. The highest ecological risk regions reached an area of 192,000 km2 in 2020 and decreased by 1.78 times from 2020 to 2040, these areas showed high spatial correlation and aggregation. (3) Topographical, climate, and socioeconomic factors had certain impacts on landscape ecological risk. Elevation (24.4%) was the most important factor affecting ecological risk, followed by temperature (19.1%), precipitation (15.7%), slope (13.6%) and GDP (8.4%). The study not only proposes a novel method regarding prediction and quantitative assessment of ecological risk based on influencing factors, but also provides a more precise and specific decision-making basis for sustainable development of ecological safety and social economic in the CFPE. [ABSTRACT FROM AUTHOR]

Wolfberry (Lycium barbarum L.) production in arid and semi-arid areas is drastically affected by the low utilization rate of soil and water resources and the irrational application of water and nitrogen fertilizers. Thus, this study explored a high-yielding, high-quality, and efficient irrigation and nitrogen regulation model to promote the production efficiency of wolfberry and rational utilization of water and land resources in arid and semi-arid areas. We compared and analyzed the effects of different soil water treatments (the upper and lower limits of soil water were estimated as the percentage of soil water content to field water capacity (θf), with the following irrigation regimen: adequate irrigation (W0, 75–85% θf), mild water deficit (W1, 65–75% θf), moderate water deficit (W2, 55–65% θf), and severe water deficit (W3, 45–55% θf)) and nitrogen levels (no nitrogen (N0, 0 kg·ha−1), low nitrogen (N1, 150 kg·ha−1), moderate nitrogen (N2, 300 kg·ha−1), and high nitrogen (N3, 450 kg·ha−1)) on the growth, physiology, and production of wolfberry. The results showed that water regulation, nitrogen application level, and their interaction significantly affected plant height and stem diameter growth amount (p < 0.05). Additionally, the relative chlorophyll content of wolfberry leaves first increased and then decreased with increasing nitrogen levels and water deficit. The average net photosynthetic rate (Pn), stomatal conductance (gs), intercellular carbon dioxide concentration, and transpiration rate (Tr) reached the highest values in plants exposed to W0N2 (19.86 μmmol·m−2·s−1), W1N1 (182.65 mmol·m−2·s−1), W2N2 (218.86 μmol·mol−1), and W0N2 (6.44 mmol·m−2·s−1) treatments, respectively. Pn, gs, and Tr were highly correlated with photosynthetically active radiation and water vapor pressure difference (goodness-of-fit: 0.366–0.828). Furthermore, water regulation and nitrogen levels exhibited significant effects on the yield and water- (WUE), and nitrogen-use efficiency (NUE) (p < 0.01), and their interactions exhibited significant effects on the yield, WUE, and nitrogen partial productivity of wolfberry plants (p < 0.05). Moreover, the contents of total sugar, polysaccharides, fats, amino acids, and proteins were the highest in W1N2, W1N2, W1N2, W2N3, and W0N2 treatments, respectively, which were increased by 3.32–16.93%, 7.49–54.72%, 6.5–45.89%, 11.12–86.16%, and 7.15–71.67%, respectively. Under different water regulations (except for the W3 condition) and nitrogen level treatments, the net income and input–output ratio of wolfberry were in the order W1 > W0 > W2 > W3 and N2 > N3 > N1 > N0. The TOPSIS method also revealed that the yield, quality, WUE, NUE, and economic benefits of wolfberry improved under the W1N2 treatment, suggesting that WIN2 might be the most suitable irrigation and nitrogen regulation model for wolfberry production in regions with scarce land and water resources such as the Gansu Province and areas with similar climate. [ABSTRACT FROM AUTHOR]

Farming-pastoral Ecotones in China (FPEC) is one of the most fragile ecological area in China. Landscape ecological risk assessment of FPEC based on terrain gradients has important strategic significance for ensuring national ecological security and the sustainable development of social economy. Based on the 30 × 30 m land use data and DEM data of FPEC in 1980, 1990, 2000, 2010 and 2020, this paper constructs a landscape ecological risk assessment model, and uses the methods of spatial autocorrelation analysis and terrain distribution index to appraise the dynamic change law and influential factors of FPEC landscape ecological risk on various terrain gradients. The results showed that: (1) In recent 40 years, land use/land cover changes (LUCC) has significantly changed, and the farmland area has increased continuously, mainly transferred from grassland, forest and bare land, particularly the bare land converted into grassland in recent 10 years, which leads to substantial increase in grassland area. (2) The overall ecological risk of the study area showed an upward trend, and the area of highest risk regions has increased more than twice during the study period, mainly distributed in the regions of "interference of human activities in low terrain" and "change of natural high terrain environment," these regions showed a high spatial concentration. (3) Ecological risk along with terrain gradient distribution is mainly limited by climate and terrain factors, the interference of human activities and natural environment change are the main influential factors of ecological risk increase in low and high terrain, respectively. Therefore, it is necessary to adapt to local conditions, and low terrain should rationally develop and utilize natural resources to reduce the interference of unreasonable production and human activities. In order to promote the sustainable and healthy development of FPEC, the policy of closing hillsides to facilitate afforestation should be adopted in the high terrain to reduce the impact of natural environment changes. [ABSTRACT FROM AUTHOR]

This study was about the water-nitrogen regulation model and its soil nutrient environment effect for increasing the yield and efficiency of Bromus inermis in the Hexi Corridor, Gansu Province, China. Bromus inermis was used as the research object in this study and four irrigation management types and four nitrogen application levels were set. The four irrigation management types (controlled by the percentage of field capacity (θf) at the jointing stage) were 75–85% (W0), 65–85% (W1), 55–85% (W2) and 45–85% (W3). The four nitrogen application levels were pure nitrogen 0 kg·ha−1 (N0), 60 kg·ha−1 (N1), 120 kg·ha−1 (N2) and 180 kg·ha−1 (N3). The effects of water-nitrogen regulation on the spatial and temporal distribution of soil moisture and nitrate nitrogen (NO3−–N), plant height, chlorophyll content, yield and water-nitrogen use efficiency of Bromus inermis were studied. Results demonstrated that (1) soil water content (SWC) was mainly affected by irrigation and W1 treatment helped maintain shallow soil (0–40 cm) water's stability and avoided water redundancy or deficit in the 60–80 cm soil layer. The distribution of soil NO3−–N was mainly affected by nitrogen application. The N2 treatment could effectively increase the NO3−–N content in shallow soil (0–40 cm) and prevent nitrate-nitrogen leaching in the 60–100 cm soil layer. (2) Irrigation and nitrogen application could significantly increase the plant height and chlorophyll content of each cut of Bromus inermis. The average plant height and chlorophyll content of the N2W1 treatment were 66.99% and 30.30% higher than N0W3. (3) At the same time, irrigation and nitrogen application could significantly increase the yield of each cut of Bromus inermis, and the interaction between the two had a significant effect on the total yield. The total yield of the N2W1 treatment was the highest (12,259.54 kg·ha−1), 157.95% higher than N0W3. Irrigation and nitrogen application could significantly improve the water-nitrogen use efficiency of Bromus inermis, and their interaction only significantly impacted the partial-factor productivity of the applied nitrogen (PFPN). Meanwhile, the N2W2 treatment had the highest water use efficiency (WUE) (23.12 kg·m−3), and the N1W1 treatment had the highest PFPN (170.87 kg·kg−1). In summary, the moderate nitrogen application rate (120 kg·ha−1) combined with mild water deficit (65–85% θf at the jointing stage) could not only promote the high yield of Bromus inermis, but also avoid the leaching of water and nitrogen in deep soil. It is a suitable water and nitrogen management mode for Bromus inermis in the Hexi Corridor of Gansu Province, China. [ABSTRACT FROM AUTHOR]

Due to increasing requirements on water resources and a lower recharge rate, the farming seasons are a vital season for the management of groundwater and surface water resource management. This condition necessitates the use of combined water distribution to meet the full water requirements. Analysis of existing surface water resources and related restrictions, this research suggested an algorithm for aquifer stabilization and fulfilling optimum water requirements. To manage the optimum withdrawals and the subsequent drop, this technique first employed the MODFLOW model for simulating the water levels. Next, an improved feed-forward neural network (IFFNN) was combined with an optimization method to create a machine learning (ML) framework. During the last phase, the findings of the optimized connectives approach as well as the relevant fields technologies to determine using improved bald eagle search with least square SVM(IBES-LSSVM) method that predicted the level of water deficit for every period, especially during farming seasons. This approach is based on an improved bald eagle search (IBES) optimization technique for finding the best settings for a least-squares support vector machine (LSSVM). The findings revealed that between 2005 and 2020, the year with the biggest water deficit was 2018 when only roughly 64 percent of water need was satisfied by groundwater (69 percent) and surface water (64 percent) (33 percent). The water depth may have risen by around 0.7 m during the study period if the optimum model had been used. The outcome of this research will help the management forecast future water shortages and make smarter water strategic choices. [Display omitted] • We used the findings of the optimized connectives approach to determine an IBES-LSSVM method. • The water depth may have risen by around 0.7 m during the study period if the optimum model had been used. • The outcome of this research will help the management forecast future water shortages and make smarter water strategic choices. [ABSTRACT FROM AUTHOR]