Organic vegetable cultivation reduces N leaching while increasing the relative soil N budget (vol 213, pg 803, 2019)

摘要

Excessive nitrogen application has caused serious environmental problems in the vegetable field. Based on a 12-year greenhouse trial of organic (ORG), low-input (LOW) and conventional (CON) vegetable production in northern China, a two-year study on nitrogen (N) budget was conducted to evaluate N management and its environmental impact. The main results were as follows: 1) total N contents in the 0-20 cm soil layer were significantly higher in ORG; 2) ORG statistically increased vegetable yield and decreased yield-scaled nitrous oxide emissions; 3) N leaching was the primary N loss pathway in three systems and ORG significantly reduced N leaching intensities (the ratio of cumulative N leaching to N inputs) and cumulative N leaching as compared to CON; and 4) ORG significantly increased relative N budgets and had the potential to accumulate organic N. These results indicated that under the condition of similar N inputs, long-term organic vegetable cultivation could reduce N leaching and increase soil organic N stock, thus may be a feasible strategy to improve greenhouse vegetable production in northern China.