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【Objective】 Reference crop evapotranspiration (ET0) is a critical parameter for irrigation and water management. This paper proposes a method for real-time forecasting ET0 using weather forecast data and a deep learning approach. 【Method】 The study was conducted in Xiaoshan District, Hangzhou City, Zhejiang Province. Hourly measured weather data and 1-7 day forecasted weather data from April 24, 2021 to December 31, 2023 were used as the dataset. The forecasting accuracy of the weather data was analyzed. A deep learning model based on the backpropagation (BP) neural network algorithm was developed and deployed for online training using Alibaba Cloud servers. 【Result】 The accuracy of the input parameters was generally reliable, with minimum temperature forecasts being more accurate than maximum temperature forecasts. Forecasting accuracy decreased as the lead time increased. Errors were observed in forecasting weather types and wind scales. The ET0 predicted by the model closely matched those calculated using real-time data, demonstrating high forecasting accuracy. During the training period, the model achieved a maximum accuracy of 91.56%, with an average root mean square error (RMSE) of 0.828 mm/day and a mean absolute error (MAE) of 0.667 mm/day. During the testing period, the model achieved an accuracy of 84.75%, with the average RMSE and MAE being 1.049 mm/day and 0.829 mm/day, respectively. 【Conclusion】 By using publicly accessible weather forecast data and an online-trained BP neural network model, real-time ET0 forecast can be achieved with high accuracy. This approach offers valuable support for farmers, enabling informed and timely irrigation decisions.

【Objective】 Garlic is a cash crop in Dali, but its irrigation with livestock wastewater risks environmental pollution. This paper studies the combined effect of livestock wastewater irrigation and nitrogen fertilization on growth, yield, water and nitrogen utilization efficiency of garlic, as well as soil nitrogen in attempts to screen a sustainable livestock wastewater irrigation schedule for garlic production in this region. 【Method】 The experiment was conducted at the National Agricultural Environmental Dali Observation and Experimental Station. There were five treatments: freshwater irrigation without nitrogen application (CK), freshwater irrigation with 390 kg/hm2 of nitrogen application (C1), freshwater irrigation with 312 kg/hm2 of nitrogen application (C2), livestock wastewater irrigation without nitrogen application (R1), livestock wastewater irrigation with 150 kg/hm2 of nitrogen application (R2). In each treatment, we measured the growth indexes, including dry weight, height, stem diameter and leaf area index of the garlic at different growing stages, as well as yield, and water and nitrogen use efficiency of the garlic and soil nitrogen content. 【Result】 The growth of the garlic was the best in R2, but was comparable with that in R1 and C1; R2 gave the highest yield. Compared to CK, C1, C2, R1 and R2 increased the bulb yield by 111.30%, 81.23%, 98.19%, and 142.01%, respectively. The nitrogen absorption and use efficiency of R1 and R2 was 154.71% and 92.25% higher than that of C1, respectively; the nitrogen partial factor productivity of R1 and R2 was 110.75% and 47.63% higher than that of C1, respectively. Compared to C1, R1 reduced the irrigation water productivity and soil nitrogen in the 0-40 cm of soil layer by 29.19%, while R2 increased the irrigation water productivity by 2.34% and reduced soil nitrogen in the 0-40 cm of soil by 3.89%, respectively. Compared to C1, R1 and R2 increased nitrogen in the 0-20 cm of soil layer by 170.90% and 255.93% respectively. 【Conclusion】 Livestock wastewater irrigation combined with appropriate base nitrogen fertilization can sustain garlic growth and yield. Livestock wastewater irrigation improved the nitrogen use efficiency and nitrogen partial factor productivity, with limited effect on average soil total nitrogen.

【Objective】Cultivation of sweet corn has increased over the past decades in some areas of China, but its demand for water and the associated irrigation strategies are poorly documented. The objective of this paper is to plug this knowledge gap. 【Method】A two-year field experiment designed based on the principle of achieving high yield was conducted. During the experiment we measured the change in soil moisture and meteorological factors, and used them to calculate water requirement, water consumption and crop coefficient (kc) of the crops. These help us to optimize the irrigation strategy for sweet corn production. 【Result】The water requirement, daily water consumption during the growth season of the sweet corn in 2016 and 2017 were 197.7 and 212.9 mm, 3.0 mm/d and 3.1 mm/d respectively. The daily water consumption varied with growth stage, being highest in the tasseling stage and least in the seedling stage. The average crop coefficient in 2016 and 2017 was 0.63 and 0.67, respectively, and the optimal calculation showed that changing irrigations times to four could reduce irrigation water by 31.84% to 33.97% compared to the currently used irrigation strategy. 【Conclusion】Water requirement of the sweet maize was low and its water consumption was similar to normal corn. Appropriate irrigation is essential to safeguarding its production.

Poultry and livestock farming wastewater is one of the main sources of agricultural non-point source pollution. Using reclaimed poultry and livestock farming wastewater for rice irrigation can not only provide nutrition for rice, but also reduce agricultural water consumption, and also further control non-point source pollution through the self-purification of rice ecosystem. It has been considered to be environmentally friendly and reliable for poultry and livestock farming wastewater treatment. However, the effect of reclaimed water irrigation on rice yield and quality is still unclear. In order to explore the effects of reclaimed water irrigation on rice yield and quality, we conducted a rice reclaimed irrigation experiment in the Erhai lake basin in 2017. The rice yield and quality were compared among different irrigation modes, different irrigation water quality and different fertilization schemes of reclaimed water. The results showed that the yield of W1F2, under intermittent irrigation with reclaimed water, was the highest, reaching 11.7t/hm2. The differences of rice yield and its components between different irrigation and fertilization methods were not significant. The yield and its components of rice under different irrigation and fertilization treatments were not significant. In terms of yield, the intermittent irrigation was 7.6% higher than that of flood irrigation. The amount of fertilizer applied by intermittent irrigation of reclaimed water was 7.0% less than that of clear water, and the yield increased by 3.5%. Correspondingly, the amount of fertilization of flood irrigation of reclaimed water is equivalent to that of clear water, which increases yield by 1.9%. In summary, the effect of reclaimed water irrigation on yield increase is obvious. There were significant differences in brown rice rate and chalky grain rate between different irrigation modes, which showed that the brown rice rate of intermittently irrigated rice was 0.7% smaller than that of flooded rice, and the white grain of intermittently irrigated rice was 45% larger than that of flooded irrigation. Intermittent irrigation has an adverse effect on the processing quality and appearance quality of rice. There were significant differences in brown rice rate, whole milled rice rate, gel consistency and depletion value under different irrigation water quality. The results showed that the brown rice rate and the depletion value of reclaimed water irrigation were smaller than those of clear water, and the whole milled rice rate and gel consistency were larger than that of clear water. Regularity, reclaimed water irrigated rice processing quality and cooking taste quality is better. In terms of nutritional quality of rice, the crude protein content in flooding treatment was 4.2% higher than that in intermittent irrigation, and the irrigation treatment of reclaimed water was 13.8% higher than that in clear water irrigation.

Northeast China plays a crucial role as a major grain-producing region, and attention to its land use and land cover changes (LUCC), especially farmland changes, are crucial to ensure food security and promote sustainable development. Based on the Moderate Resolution Imaging Spectroradiometer (MODIS) data and a decision tree model, land types, especially those of paddy fields in Northeast China from 2000 to 2020, were extracted, and the spatiotemporal changes in paddy fields and their drivers were analyzed. The development trends of paddy fields under different future scenarios were explored alongside the Coupled Model Intercomparison Project Phase 6 (CMIP6) data. The findings revealed that the kappa coefficients of land use classification from 2000 to 2020 reached 0.761–0.825, with an overall accuracy of 80.5–87.3%. The proposed land classification method can be used for long-term paddy field monitoring in Northeast China. The LUCC in Northeast China is dominated by the expansion of paddy fields. The centroids of paddy fields gradually shifted toward the northeast by a distance of 292 km, with climate warming being the main reason for the shift. Under various climate scenarios, the temperature in Northeast China and its surrounding regions is projected to rise. Each scenario is anticipated to meet the temperature conditions necessary for the northeastward expansion of paddy fields. This study provides support for ensuring sustainable agricultural development in Northeast China. [ABSTRACT FROM AUTHOR]

Ridge–furrow cropping patterns, nitrogen fertilisation and seed rate regulation are popular management strategies for improving crop yields in the semi‐arid areas of Northwest China, but their interactive effects on grain yield and water use efficiency remain poorly understood. In 2020–2021 and 2021–2022, a two‐season field experiment was conducted on winter wheat. There were two cropping patterns (C), ridge–furrow cropping with film mulch (RC) and traditional cropping without mulch (TC), two nitrogen fertilisation rates (N), 0 and 200 kg N ha−1 (N0 and N1) and three seed rates (S), 240, 360 and 480 plants m−2 (S1, S2 and S3). The study was conducted in a split–split design with three replications (randomised blocks) and a total of 24 experimental plots. It was found that the interactive effects of C × N, C × S and N × S were significant on soil temperature (ST), leaf area index (LAI), relative chlorophyll content (SPAD), photosynthetic parameters, grain yield (GY) and water use efficiency (WUE) (p < 0.05), while C × N × S was significant only for LAI, aboveground biomass (AGB), GY and WUE (p < 0.05). Compared with TC and N0, RC and N1 significantly increased SPAD value (2.4% and 15.8%), net photosynthetic rate (Pn) (19.8% and 32.8%), net photosynthetic rate (Pn), transpiration rate (Tr) (7.0% and 15.7%) and the effective PSII quantum production (ΦPSII) (10.7% and 5.0%). The highest GY (6773 kg ha−1 over 2020–2021 and 8036 kg ha−1 over 2021–2022) and WUE (20.03 kg ha−1 mm−1 over 2020–2021, and 21.77 kg ha−1 mm−1 over 2021–2022) of winter wheat were observed under RC + N1 + S2. The findings showed that the RC cropping pattern with fertilisation and seed rate regulation (360 plants m−2) of winter wheat, which is appropriate for ensuring the long‐term sustainability of agricultural production in the semi‐arid regions of Northwest China, enhanced plant growth, photosynthetic traits, yield and water use efficiency. The study might give useful information for enhancing the productivity and water use efficiency of winter wheat in this and other similar climate locations. [ABSTRACT FROM AUTHOR]

Various agronomic practices can affect the processes of aboveground dry matter accumulation (source) and grain filling (sink), resulting in yield differences. Improved source-sink relationships can facilitate the production and accumulation of assimilates to increase the productivity of winter wheat (Triticum aestivum L.). A two-season field experiment was undertaken on winter wheat during 2020–2021 and 2021–2022. In a split-split-plot design with three replicates (randomized blocks), we compared two planting modes (ridge-furrow planting with plastic mulching [RFPM]; traditional flat planting [TF]), two complementary irrigation levels (I30+30: 30+30 mm; I0: no irrigation), and three planting densities (D1, D2, and D3: 240, 360, and 480 plants m−2). The results showed that RFPMI30+30 significantly increased maximum yield by 28.5% compared with TFI0. Although D3 increased the number of effective spikes per unit area and duration of grain filling compared to D2, it reduced the number of grains per spike, 1000-grain weight, and average filling rate. Compared to TF and I0, RFPM and I30+30 improved the sink/source ratio by 5.3% and 6.5%, respectively. Grain yield peaked at D2 in the RFPM and at D3 in the TF. Medium planting density (D2) and complementary irrigation (I30+30) during the wintering and reviving periods under RFPM can achieve better source-sink balance relationships and the maximum grain yield of winter wheat. Overall, we believe that in most cases, wheat yields are source-limited and can be improved by ridge-furrow planting with plastic mulching, complementary irrigation, and planting density regulation. [ABSTRACT FROM AUTHOR]