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To improve the yield and water-nitrogen (N) use efficiency of summer maize, a two-year field experiment with four irrigation soil layers (0–10, 0–20, 0–30, and 0–40 cm, denoted as W10, W20, W30, and W40, respectively) and three N applications (180, 240, and 300 kg ha–1, denoted as N180, N240, and N300, respectively) was performed using micro-sprinkling irrigation system in 2018 and 2019. The interaction between water and N application significantly affects dry matter accumulation (DM). Under the same N application, the grain yield of W10 was significantly lower than that of W40. The irrigation amount and evapotranspiration for W20N180 and W20N240 significantly decreased by 47.18%–52.31% and 12.32%–12.68%, respectively, over that of W40N300, and water-use-efficiency (WUE) significantly increased by 7.75%–12.47%. Compared with N180, the N partial factor productivity of N240 and N300 decreased by 21.02%~22.04% and 37.12%~38.24%, respectively; with no significant difference in yield. Grain yield was significantly positively correlated with leaf area index at tasseling, grains per ear, DM at maturity, and evapotranspiration. Overall, suitable irrigation (W20) and N application (180–240 kg ha–1) can achieve higher grain yield and WUE for summer maize in the Huang-Huai-Hai Plain of China. [ABSTRACT FROM AUTHOR]

Purpose: It has always been challenged to improve heavy coastal silt saline soil for crop productions through establishing an irrigation system with saline water. This study was aimed to investigate the effect of the electricity conductivity of irrigation water (ECw) on soil salinity (ECe), sodium adsorption ratio (SAR) and pH of the saturated paste (pHs), tomato yield, and irrigation water use efficiency (IWUE). Methods: A two-year field experiment of five ECw treatments (0.7, 3.2, 4.7, 6.2, and 7.8 dS m−1, respectively) was conducted under ridge tillage in the Bohai Rim region, China through a drip irrigation system. Results: A linear correlation between ECw and soil desalinization rate (SDR) and between the irrigated water amount and SDR was revealed and the final average ECe, SAR and pHs readings at 1 m deep soil (40.2 dS m−1, 56.2 (mmol L−1)0.5, and 7.82, respectively) dropped to those within the main root zone with each of five treatments (21.3–26.6 dS m−1, to 32.4–37.1 (mmol L−1)0.5 and 7.16–7.75, respectively), indicating an outstanding soil reclamation. The tomato survival rate was over 90% when the ECw was kept below 7.8 dS m−1, while growth and yield of tomato and IWUE were generally unaffected as the ECw was below 4.7 dS m−1. Conclusion: The ECw of dripping water should be maintained below 3.9 dS m−1 and the soil matrix potential be controlled above -5 kPa at 20 cm deep soil beneath dripping emitters for a high-yield tomato cultivation in the heavy coastal silt saline lands. [ABSTRACT FROM AUTHOR]