Negative pressure irrigation (NPI), which is a new subsurface irrigation technique, promotes vegetable yield, water productivity (WP), and nitrogen use efficiency (NUE). However, it is not clear how NPI improves vegetable growth, especially in terms of water supply characteristics and uniformities of soil water and nitrogen. In this study, a cucumber pot experiment that had 0 kPa (PW1), –5 kPa (PW2), –10 kPa (PW3), –15kPa (PW4), and traditional irrigation (PCK) treatments under nitrogen application (N1) and no application (N0) was conducted to reveal the water supply characteristics of NPI and its effect on vegetable growth. There are two main water supply characteristics: 1) automatically supplying irrigation water based on the consumption of soil water, and 2) keeping soil water content stable during the vegetable growth period. In addition, the relationship between vegetable growth and soil water and NO₃^–-N distribution uniformities throughout the soil profile was investigated by carrying out two tomato field experiments. The treatments of one tomato experiment were NPI with –5 kPa (F1W) and furrow irrigation (F1CK). We also carried out NPI with –5 kPa (F2W), furrow irrigation (F2CK), and drip irrigation (F2D) in another tomato experiment. The results showed that cumulative water application under N1 was higher than under N0 in the PW1, PW2, and PW3 treatments in the cucumber experiment. Volumetric soil water content under the NPI system was more stable during the vegetative growth period than under traditional irrigation. The NPI system also increased yields under appropriate pressures (–10–0 kPa) compared to the PCK treatment in the cucumber experiment. The NPI in the two tomato experiments reduced fertilizer inputs and irrigation compared to furrow irrigation and drip irrigation. However, the irrigation method had no significant influence on the tomato yield in the two tomato experiments.

负压灌溉（NPI）是一种新的地下灌溉技术，可提高蔬菜产量，水分生产率（WP）和氮利用效率（NUE）。但是，尚不清楚NPI如何改善蔬菜的生长，特别是在供水特性以及土壤水和氮的均匀性方面。在本研究中，进行了一个黄瓜盆栽试验，该试验在施氮（N1）和没有进行任何应用（N0）以揭示NPI的供水特性及其对蔬菜生长的影响。主要有两个供水特征：1）根据土壤水的消耗量自动提供灌溉水； 2）在蔬菜生长期保持土壤水分稳定。此外，₃ ^–通过进行两个番茄田间试验，研究了整个土壤剖面的-N分布均匀性。一项番茄实验的处理方法为NPI –5 kPa（F1W）和沟灌（F1CK）。在另一个番茄试验中，我们还以–5 kPa（F2W），沟灌（F2CK）和滴灌（F2D）进行了NPI。结果表明，在黄瓜试验中，PW1，PW2和PW3处理在N1下的累积水分施用量高于在N0下。在营养生长期，NPI系统下的土壤体积水含量比传统灌溉下的更为稳定。与黄瓜实验中的PCK处理相比，在适当的压力（–10–0 kPa）下，NPI系统还提高了产量。与沟灌和滴灌相比，两次番茄试验中的NPI减少了肥料投入和灌溉。然而，在两次番茄试验中，灌溉方式对番茄产量没有显着影响。