Achieving the goal of increasing both crop yield and water-use efficiency with a better irrigation regime is a major challenge in semi-arid areas. In this study, we presented a two-season field experiment (October 2018–June 2019 and October 2019–June 2020) that considered drought stresses, i.e., no irrigation (W0), irrigated in jointing (W1), both in jointing and flowering (W2) after re-greening, and wheat varieties (S086; J22). The results showed that a 45.5% excess of irrigation water input did not promote wheat yield (W1 vs. W2). S086 was beneficial for the usage of soil water consumption under a low amount of irrigation water in both seasons. In addition, irrigation positively affected the activities of superoxide dismutase and catalase in flag leaves (p < 0.05). A decrease in irrigation helped to increase the concentrations of soluble sugar and proline and decrease the amount of malondialdehyde content for S086. For the water- and irrigation-water-use efficiency, W1 was significantly increased by 20.6–21.7% and 38.3–39.3% in 2018–2019 and 23.4–24.4% and 43.8–44.7% in 2019–2020, respectively, as compared to W2. Additionally, a higher yield for S086 than J22 was found under deficit irrigation. Consequently, our study suggested that the S086 variety combined with a total amount of irrigation water of 165 mm might be recommended to meet the win–win goal of high crop yields and water-use efficiency for reducing ground water depletion in the future.

With the development of sustainable agriculture, trials on the benefits of the application of organic fertilizers around the world have been conducted. Herein, we investigated the impact of the pure chemical fertilizers (CFs) combined with organic fertilizers compared with the application of CFs (100% CFs) and no fertilizers (NFs) on soil properties as well as the yield and quality of Chinese cabbage through meta-analysis. Results indicate that: (1) Compared with NFs, the application of organic fertilizers can significantly improve the yield and quality of Chinese cabbage and increase soil nutrients. (2) Compared with CFs, the application of organic fertilizers can increase the fresh weight, number of leaves, transverse diameter, leaf length, and development of Chinese cabbage per plant, with increases of 8.54%, 6.6%, 9.905%, 8.42%, and 10.03%; Meanwhile, organic fertilizers can significantly increase the yield (total amount of above-ground parts produced) and commercial yield (the portion that meets the required quality standards and is intended for sale) of Chinese cabbage to increase the yield and commercial yield by 10.08% and 35.56%, respectively. However, it has no significant impact on the income from growing Chinese cabbage. (3) Compared with CFs, the application of organic fertilizers can significantly increase the content of vitamin C (11.06%), soluble sugar (19.16%), and soluble protein (8.83%) and reduce the content of nitrate and nitrite in Chinese cabbage, with a reduction of up to 19.02% and 20.9%, respectively. The application of organic fertilizers will also have a certain impact on the absorption of heavy metals in Chinese cabbage. (4) Compared with CFs, the application of organic fertilizers can significantly improve soil organic matter, soil carbon sequestration, nitrogen absorption, and potassium absorption, showing increases of 12.73%, 13.19%, 7.91%, and 7.37%, and the application of organic fertilizers reduces soil electrical conductivity and available nitrogen, showing decreases of 36.78% and 38.75%, respectively. (5) The application of organic fertilizers significantly increased the content of soil urease and soil sucrase, increasing by 9.42% and 17.16%, respectively. This study helps inform the application of organic fertilizers in Chinese cabbage production.

Water resource shortage and unreasonable application of nitrogen (N) fertilizer have been problems in wheat production of northern China. However, the interaction effects of water regimes and N practices on wheat root growth, grain yield, soil water, and inorganic N changes as well as water-N use efficiency are still unclear under drip irrigation. A field experiment was conducted during the 2020–2021 and 2021–2022 winter wheat (Triticum aestivum) growing seasons. In this study, three irrigation schedules (i.e., irrigation was applied up to 80% [D1], 75% [D2], and 70% [D3] as soon as the soil water content decreased to 65%, 60% or 55% of field capacity) and two N practices (i.e., N applied at the base, jointing, booting stages were 90, 72, 48 kg ha⁻¹ [N1], and the base, jointing, booting, filling stages were 90, 40, 40, 40 kg ha⁻¹ [N2], respectively) were considered. The decease in irrigation water amount was offset by the increase in soil water consumption. In addition, N practices significantly interacted with irrigation on soil NO₃⁻–N accumulation (2021–2022), NH₄⁺–N accumulation, SPAD value (2020–2021), N content in stems and grains at maturity, and average root length and weight density at the flowering stage. Irrigation, rather than N practices, significantly affected grain yield, total N uptake, crop N transformations (NT), the contribution of NT to grain (NTPC), water and N productivity, in which, for the value of these two seasons, D2 increased total N uptake by 18.1% (p < 0.05), and NT by 39.4% (p < 0.05) under N1 as compared to D3. Additionally, the highest WUE and ANUE were found in D2 during 2021–2022. Heavy irrigation water amount caused high a LAI; further analysis proved that the LAI was the key factor affecting grain yield, and positively and significantly correlated to yield. However, no significant difference in the LAI between D1 and D2 was found. N1 was beneficial to prevent N leaching and increase water and N use efficiency, biomass, and N transformation amount. This study recommends that D2 + N1 might be a promising system for manipulating irrigation and fertilization practices under sub-surface drip irrigation systems to improve water and N use efficiency and grain yields in semi-arid regions.

Circular agriculture is an inevitable trend in the sustainable development of global agriculture. At present, there are issues such as insufficient utilization of resources, serious land pollution, and lack of technical support in circular agricultural ecological parks. This study explores the safe application of organic fertilizer to field crops within circular agricultural ecological parks. A peanut (Arachis hypogaea L.)–wheat (Triticum aestivum L.)–maize (Zea mays L.) crop rotation system was selected to research safe application methods of biogas residues on the peanut–wheat–maize crop rotation system. In this experiment, we set up different amounts of biogas residues as the base fertilizers, with no fertilizer and only chemical fertilizer treatments serving as controls. We determined the yield, quality, heavy metal content, and nutrient uptake of wheat, maize, and peanuts, as well as soil nutrient content and heavy metal content under different biogas residue application rates. The results of the experiment are as follows: (1) Biogas residue as a base fertilizer increased the yield of peanuts, wheat, and maize. The highest yield for each crop occurred when the biogas residue amount was 67,500 kg hm⁻², with yield increases of 36.7%, 26.6%, and 14.1% for peanuts, wheat, and maize, respectively, compared to the no fertilizer treatment. (2) The application of biogas residue improved the seed quality of peanuts, wheat, and maize. The B3 treatment showed strong quality improvement potential, increasing peanut crude protein content by 3.92–7.48%, soluble sugar content by 36.99–49.70%, crude fat content by 0.95–3.27%, wheat crude protein content by 2.22–8.72%, soluble sugar content by 6.21–8.51%, maize crude protein content by 2.87–3.61%, and soluble sugar content by 21.62–28.05% compared to the control. (3) The application of biogas residue enhanced the uptake of nutrients by crops and increased the contents of effective nutrients in the soil. (4) The application of biogas residue did not cause excessive accumulation of heavy metals in crops and soil. In conclusion, the application of biogas residue positively impacts crop growth, quality, and soil health in circular agricultural ecological parks, and has potential in agricultural production systems. Future research should focus on determining the optimal ratio of organic and chemical fertilizers, their efficient use, and the mechanisms by which organic fertilizer application can increase crop yield and quality, as well as improve soil quality.

In response to water scarcity in the Bashang area of northwest Hebei Province, a cold and arid region in north China, and to address the diminishing groundwater levels caused by pumping irrigation, this study investigated the impact of rainwater tank size and water supply on kidney beans production in greenhouses under various precipitation scenarios to determine the production potential and development strategies for regional precipitation resources. Under the background of average annual precipitation, kidney bean yield increased with increasing reservoir volume and shorter irrigation cycles. Under a 4-day irrigation cycle, the water demand satisfaction rate of kidney beans reached 100% water demand when the rainwater tank size was 15.7 m³. Against the wide variation in multi-year regional precipitation from 1992 to 2023, the annual effect of rainwater harvest was simulated using precipitation data collected 20 years with an 80% precipitation guarantee rate. The average minimum yield reduction rate obtained was 9.4%, and the corresponding minimum rainwater tank size was 29.5 m³. By superimposing the rainwater harvested in the shed and nonshed areas, the volume of the reservoir without yield reduction could be reduced to 20.0 m³. The sum of discharged and inventory water was much greater than the water scarcity in each water supply situation. Simulating and analyzing the effect of the relationship between rainwater tank size and water supply on rainwater harvesting in regional farmland by year provides important data affecting the construction of regional rainwater storage facilities and water supply efficiency. To achieve a high, stable yield of kidney beans grown in a greenhouse with shed film and shed area rainwater harvesting in north China, 2.6 m³ supplementary groundwater irrigation is still needed during the annual growing season.

Water and fertilizer are the two indispensable elements in agriculture. The rational use of soil water and fertilizer can not only improve crop yield and quality rate, but also alleviate land pollution and water shortage. Water and fertilizer management in Chinese cabbage (Brassica rapa spp. pekinensis) involves in improper irrigation and fertilization. This experiment was conducted to explore he shoot growth, root traits, nutrient contents, soil microbial population and soil enzyme activities of Chinese cabbage in response to different irrigation and organic fertilizer application rates. The experiment consisted of three irrigation levels (A1-A3: 90%-70% ± 5% of field water holding capacity), five organic fertilizer application rates (B1-B5: 10%-50% cattle manure with nitrogen replacement) and CK treatments (CK1: regular fertilizer, CK2: 100% cattle manure with nitrogen replacement). The results showed that irrigation rate A2 was the better irrigation rate. At this irrigation rate B2 treatment significantly increased shoot fresh weight by 22.65% and 31.09% compared to CK1 and CK2, respectively. Organic fertilizer application increased the SPAD value of Chinese cabbage, but the trend was not consistent under different irrigation and organic fertilizer levels. All irrigation levels showed more soil available K content in CK2. Compared to other treatments, CK2 was enhanced by 20.70%-317.42% under A1, 7.34%-235.68% under A2, and 28.16%-188.42% under A3 irrigation. Adequate irrigation is prerequisite to enhance root fresh weight, while lower irrigation and organic fertilizer helps to promote root length and root surface area. Soil enzyme activity and bacteria were significantly higher in A1 and A2 treatments than A3, while irrigation had no significant differences on soil actinomycetes and fungi. Under A1 irrigation, the B4 treatment had higher acid phosphatase and sucrase activities, 11.31%-22.46% and 4.30%-63.50%, respectively, compared to other treatments. In conclusion, the effect of organic fertilizer on soil enzyme activity and soil microbial population varied according to the irrigation levels, but generally organic fertilizer were beneficial to boost up the soil enzyme activity and soil microbial population.