Nitrogen Balance and Loss in a Greenhouse Vegetable System in Southeastern China  

作　　者：MIN Ju ZHAO Xu SHI Wei-Ming XING Guang-Xi ZHU Zhao-Liang 

机构地区：[1]State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008 (China)

出　　处：《Pedosphere》2011年第4期464-472,共9页土壤圈（英文版）

基　　金：Supported by the National Natural Science Foundation of China-Japan Science and Technology Agency (NSFC-JST);Major International Joint Research Project (No. 30821140542);the National Basic Research Program (973 Program) of China (No. 2007CB109303);the Major Science and Technology Program for Water Pollution Control and Treatment of China (No. 2008ZX07101-005)

摘　　要：High rates of fertilizer nitrogen (N) are applied in greenhouse vegetable fields in southeastern China to maximize production;however,the N budgets of such intensive vegetable production remain to be explored.The goal of this study was to determine the annual N balance and loss in a greenhouse vegetable system of annual rotation of tomato,cucumber,and celery at five N (urea) application rates (0,348,522,696,and 870 kg N ha-1 year-1).Total N input to the 0-50 cm soil layer ranged from 531 to 1 053 kg ha-1,and N fertilizer was the main N source,accounting for 66%-83% of the total annual N input.In comparison,irrigation water,wet deposition,and seeds in total accounted for less than 1% of the total N input.The fertilizer N use efficiency was only 18% under the conventional application rate of 870 kg N ha-1 and decreased as the application rate increased from 522 to 870 kg N ha-1.Apparent N losses were 196-201 kg N ha-1,of which 71%-86% was lost by leaching at the application rates of 522-870 kg N ha-1.Thus,leaching was the primary N loss pathway at high N application rates and the amount of N leached was proportional to the N applied during the cucumber season.Moreover,dissolved organic N accounted for 10% of the leached N,whereas NH3 volatilization only contributed 0.1%-0.6% of the apparent N losses under the five N application rates in this greenhouse vegetable system.High rates of fertilizer nitrogen （N） are applied in greenhouse vegetable fields in southeastern China to maximize production; however, the N budgets of such intensive vegetable production remain to be explored. The goal of this study was to determine the annual N balance and loss in a greenhouse vegetable system of annual rotation of tomato, cucumber, and celery at five N （urea） application rates （0, 348, 522, 696, and 870 kg N ha^-1 year^-1）. Total N input to the 0-50 cm soil layer ranged from 531 to 1 053 kg ha^-1, and N fertilizer was the main N source, accounting for 66%-83% of the total annual N input. In comparison, irrigation water, wet deposition, and seeds in total accounted for less than 1% of the total N input. The fertilizer N use efficiency was only 18% under the conventional application rate of 870 kg N ha^-1 and decreased as the application rate increased from 522 to 870 kg N ha^-1. Apparent N losses were 196-201 kg N ha^-1, of which 71%-86% was lost by leaching at the application rates of 522-870 kg N ha^-1. Thus, leaching was the primary N loss pathway at high N application rates and the amount of N leached was proportional to the N applied during the cucumber season. Moreover, dissolved organic N accounted for 10% of the leached N, whereas NH3 volatilization only contributed 0.1%-0.6% of the apparent N losses under the five N application rates in this greenhouse vegetable system.

关 键 词：ammonia volatilization intensive production N input N leaching N use efficiency 

分 类 号：S153.61[农业科学—土壤学] P588.121[农业科学—农业基础科学]