ABSTRACT

Micro-drip irrigation promotes high water and nutrient use efficiency in crops.We aimed to develop a new micro-drip irrigation technology that can reduce the effects of chemical fertilizer input on soil quality while maintaining agricultural productivity. There were four treatments: micro-drip irrigation with 240 (LF), 300 (MF), and 360 kg ha^-1 fertilization (HF) and subsurface drip irrigation (SDI) with 240 kg ha^-1 fertilization (CK). Micro-drip irrigation decreased N concentration around the roots by >24% compared with SDI, and increased the urease, alkaline phosphatase activities, and partial nitrogen productivity by 31.5%, 37.7%, and 22.1%, respectively. Although the HF treatment increased cucumber yield by 20%–45% compared with LF and MF, the urease and alkaline phosphatase activities decreased by 11.4%–15.3% and 11.5%–23.0%, respectively. Furthermore, the HF treatment significantly increased the N concentration around the roots. There was a negative correlation between soil enzymatic activities and N concentration. Overall, micro-drip irrigation mitigated the inhibition of soil enzymatic activities and increased nutrient uptake and cucumber yield. However, the negative effects of high fertilization on soil quality and N loss were unavoidable. The optimal fertilization level for greenhouse cucumber cultivations was 300 kg N hm^-2 under micro-drip irrigation.

摘要

微滴灌促进作物水分和养分的高利用效率。我们旨在开发一种新的微滴灌技术，可以在保持农业生产力的同时减少化肥投入对土壤质量的影响。有四种处理：240 (LF)、300 (MF) 和 360 kg ha ^-1 施肥 (HF) 的微滴灌和 240 kg ha ^{-1 的}地下滴灌 (SDI) 受精（CK）。与SDI相比，微滴灌使根部周围的氮浓度降低了>24%，尿素酶、碱性磷酸酶活性和部分氮生产力分别提高了31.5%、37.7%和22.1%。尽管与LF和MF相比，HF处理使黄瓜产量提高了20%–45%，但尿素酶和碱性磷酸酶活性分别降低了11.4%–15.3%和11.5%–23.0%。此外，HF 处理显着增加了根部周围的 N 浓度。土壤酶活性与氮浓度呈负相关。总体而言，微滴灌减轻了对土壤酶活性的抑制，增加了养分吸收和黄瓜产量。然而，高施肥对土壤质量和氮素流失的负面影响是不可避免的。^-2 下微滴灌。