Irrigation using saline water is extensively used in areas of agricultural production where freshwater is scarce. However, saline water irrigation adversely impacts soil’s physicochemical characteristics and crop productivity. In this study, we established irrigation water with five salinity levels (EC_iw, 1.3, 3.4, 7.1, 10.6, 14.1 dS·m⁻¹) to investigate how these salinity levels influenced grain yields as well as soil salinity, alkalinity, sodicity, and aggregate stability in the 0~20 cm soil layer of a wheat and maize rotation field (in 2022–2023). Tukey’s test, entropy-weighted TOPSIS, and the least squares method were used to analyze the significance analysis, comprehensively evaluate the soil aggregate stability and soil index comprehensive score (SICS), and achieve linear fitting, respectively. The results showed that when EC_iw > 3.4 dS·m⁻¹, there was a significant increase in the soil salinity, pH, and sodium adsorption ratio. When EC_iw > 7.1 dS·m⁻¹, a significant reduction in soil aggregate stability was observed. When EC_iw ≤ 3.4 dS·m⁻¹, there was no significant reduction in the grain yields of wheat and maize. Furthermore, the annual grain yields of wheat and maize decreased by 5% and 10%, respectively, resulting in a change in EC_iw values from 2.98 to 4.24 dS·m⁻¹, based on the linear regression analysis of SICS and EC_iw, as well as the annual grain yields and SICS. Under uniform irrigation conditions, the soil salinity, alkalinity, and sodicity were lower, and soil aggregate indexes were more stable at the maturity stage of maize.

Saline water irrigation has been widely used for crop production where agriculture is short of freshwater. However, information about the response of soil respiration to saline water irrigation is limited. To identify the effect of saline water irrigation on soil respiration, the experiment based on long-term saline water irrigation cotton fields (since 2006) was conducted in the Heilonggang area in 2021. Five salinity levels in irrigation water were tested (3.4 [S1], 7.1 [S2], 10.6 [S3], 14.1 [S4], and 17.7 dS m⁻¹ [S5]), and deep ground water (1.3 dS m⁻¹) was used as the control (CK). After 15 years of saline water irrigation, we monitored soil physicochemical properties and soil respiration. In addition, we developed a structural equation model of the relationship between them. The results demonstrated that saline water irrigation significantly reduced soil water-stable aggregate content and porosity by 4.42–45.33% and 6.52–14.10%, respectively, and attenuated soil cellulase, α-glucosidase, and alkaline phosphatase activity. Soil respiration under saline water irrigation was significantly reduced by 5.28–33.08%. Moreover, saline water irrigation with salinity below 10.6 dS m⁻¹ had no significant effect on cotton yield. Moreover, soil salinity (62%), water-stable aggregate content (46%), and soil porosity (25%) had significant effects on soil respiration, and soil porosity had a significant positive effect on soil alkaline phosphatase activity according to the structural equation model. Overall, saline irrigation with salinity below 10.6 dS m⁻¹ can alleviate water shortages and reduce soil carbon emissions without affecting cotton yield in the study area.

Cultivation patterns under water saving management are closely related to climate change and crop productivity. Survey data for wheat production in China, Canada, and the USA from 1965 to 2014 was analyzed through classification statistics, comparative analysis and weighting methods. The results showed that China, Canada and the USA wheat grain production accounts for 26.49% to 34.68% of global wheat production. Of these three countries, both the highest total yield and the highest average yield per area sown were in China post 1985. Since 2000, China has accounted for 10.70% to 11.12% of global wheat planted area, producing 15.73% to 17.45% of global wheat output. Achieving high wheat yield in China was mainly based on consuming more irrigation water. The per capita arable land in China, Canada and the USA was 0.10 ha, 1.31 ha and 0.70 ha, respectively. The per capita arable land in Hebei, China, Saskatchewan, Canada and Oklahoma, USA was 0.09 ha, 16.11 ha and 3.48 ha, respectively. Hengshui, China (HS) produces two crops a year. Outlook, Saskatchewan, Canada (OK) and Woodward, Oklahoma, USA (WW) produce one crop a year. Mean precipitation averages 109 mm, 210 mm and 291mm during the wheat growing season, respectively. Due to less per capita arable land in China, achieving high yield means higher water consumption, which creates a sharp contradiction between water scarcity and demand for grain in China. Consequently, high water use efficiency technologies in agriculture are more needed in China than in the other two countries. High demand for water at post 1985 yield levels cannot be met by rain-fed production in HS. Grain yields of 5975.6 kg/ha to 7031.2 kg/ha can be achieved with irrigation. Economic benefits mainly determine wheat production in the USA and Canada, whereas in China production is driven by food security and sustainable production goals. The conclusions of this paper could provide a reference for wheat production in different regions.

To discuss the water consumption patterns of winter wheat (Triticum aestivum L.) and the difference in yield traits among varieties under different irrigation systems, three field water treatments were established (jointing water, W1, CK; jointing water + flowering water, W2; and rising water + booting water + filling water, W3). Two winter wheat varieties (Hengmai4399 and Hengguan35) were selected in 2020–2021, and three (Hengmai4399, Hengguan35, and Hengmai28) were selected in 2021–2022 to investigate the impact of the irrigation amount on water consumption and its interaction with the varieties on yield traits of winter wheat. The results showed that there was a positive and significant correlation between soil water consumption and soil moisture reserve presowing; the correlation was the strongest in the 150–200 cm layer. The response of the yield of the three varieties to irrigation was Hengmai4399 > Hengmai28 > Hengguan35, and the drought resistance was Hengguan35 > Hengmai28 > Hengmai4399. When the soil water storage presowing was insufficient, Hengmai4399 combined with the W3 treatment achieved the highest yield and water use efficiency; when the soil water storage presowing was sufficient, Hengmai28 combined with the W2 treatment achieved a high-level yield and the highest WUE.

Subsurface drip irrigation is an advanced technique that significantly enhances agricultural water efficiency and conserves irrigation resources. The Heilonggang region is highly representative of the maize–wheat rotation system in China. This region was selected for conducting operations and maintenance experiments on subsurface drip irrigation systems. The primary objective of this study was to determine the most suitable type of drip tape for application in the North China Plain and to identify specific maintenance measures necessary to ensure the long-term functionality of subsurface drip irrigation systems. The experiment was conducted in Jing County, Hengshui City. Anti-blocking drip tape (Netafim Co., Ltd. Beijing, China) with automatic functionality was evenly laid in the test area. The experimental area was divided into six rotational irrigation groups. The key parameter examined in this single-factor experiment was the drip tape wall thickness, with values of 0.2, 0.225, 0.25, 0.28, 0.31, and 0.38 mm. Drip tape treatments were randomly sampled in rotational irrigation groups, and there were three repeat plots in each treatment. Each replicate plot contained ten drip irrigation belts spaced 60 cm apart, with an interval of more than 2 m between adjacent plots. The subsurface drip irrigation system was installed in October 2023. Prior to irrigation, drip tape troubleshooting was conducted and recorded manually on 12 March 2024 (wheat regreening stage) and 29 June 2024 (maize-sowing stage). The experimental findings indicated that the primary factor influencing the stability of the irrigation system was the wall thickness of the drip tapes, while other system components operated efficiently. A significant correlation was observed between the wall thickness of the drip tape and the number of water leakage points (p < 0.05), with an absolute correlation coefficient exceeding 0.9. The number of leakage points in drip tapes with wall thicknesses of 0.2–0.28 mm (267 instances) was significantly higher than those with wall thicknesses of 0.31–0.38 mm (29 instances), primarily due to damage caused by mole crickets and wireworms. Following the injection of 40% phoxim, 2.5% lambda-cyhalothrin, and 70% imidacloprid insecticides (at a cost of 16.7 USD·ha⁻¹) into the subsurface drip irrigation system, the insect pests were nearly eradicated within one month. A cumulative cost evaluation over a 6–10-year period recommended the use of drip tapes with a wall thickness of 0.31 mm and the application of insecticides every 1–2 months to maintain optimal system performance in this region. These measures can effectively support the stable operation of this irrigation technique at a relatively low cost.

Water scarcity is a key limitation to winter wheat production in the North China Plain, and it is essential to explore the optimal timing of spring irrigation to optimize N and Si uptake as well as to safeguard yields. The aim of this study was to systematically study the effect mechanism of nitrogen and silicon absorption of winter wheat on yield under spring irrigation and to provide a scientific basis for optimizing irrigation strategy during the growth period of winter wheat. In this experiment, the winter wheat ‘Heng 4399’ was used. Five irrigation periods, i.e., 0 d (CK), 5 d (AJ5), 10 d (AJ10), 15 d (AJ15), and 20 d (AJ20) after the jointing stage, were set up to evaluate the nitrogen (N) and silicon (Si) absorption and grain yield (GY). The results showed that delayed irrigation for 5–10 days at the jointing stage had increased the GY. With the delay of irrigation time, the N/Si content of the entire plant at the maturity period increased first and then decreased; among that, the maximum N contents appeared in AJ15 and AJ5 in 2015 and 2020, respectively, while the Si concentrations appeared in AJ5 and AJ10 in sequence. Compared with AJ15 and AJ20, the N accumulation of vegetative organs in AJ5 increased by 3.05~23.13% at the flowering stage, 14.12~40.12% after the flowering stage, and a 1.76~6.45% increase in the N distribution rate at maturity stage. A correlation analysis revealed that the GY was significantly and positively correlated with the N/Si accumulation at the anthesis and N translocation after the anthesis stage. In conclusion, under limited irrigation conditions, delaying watering for 5 to 10 days at the jointing stage can improve the nitrogen and silicon absorption and nutrient status of wheat plants and increase wheat yield.