Abstract
Globally,sub-optimal use of nitrogen(N)fertiliser and elevated N irrigation groundwater have led to high leached nitrate(NO3-)losses from protected vegetable field systems.Optimising fertiliser and irrigation management in different soil types is crucial to reduce future N loads from such systems.The present 4-year study examined leached N loads from lysimeter monitoring arrays set up across 18 protected vegetable system sites encompassing the dominant soil types of northern China.The treatments applied at each field site were:1)a high N and high irrigation input treatment(HNHI);2)a low N but high irrigation input treatment(LNHI)and 3)a low N with low irrigation input treatment(LNLI).Results showed that the mean annual leached total nitrogen loads from the HNHI,LNHI and LNLI treatments were 325,294 and 257 kg N ha-1 in the fluvo-aquic soil,114,100 and 78 kg N ha-1 in the cinnamon soil and 79,68 and 57 kg N ha-1 in the black soil,respectively.The N dissolved in irrigation water in the fluvo-aquic soil areas was 8.26-fold higher than in the cinnamon areas.A structural equation model showed that N fertiliser inputs and leaching water amounts explained 14.7 and 81.8%of the variation of leached N loads,respectively.Correspondingly,reducing irrigation water by 21.5%decreased leached N loads by 20.9%,while reducing manure N and chemical N inputs by 22 and 25%decreased leached N loads by only 9.5%.This study highlights that protected vegetable fields dominated by fluvo-aquic soil need management to curtail leached N losses in northern China.
基金项目
National Key Research and Development Program of China(2021YFD1700900)
National Natural Science Foundation of China(31972519)
Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(2060302-05-956-1)
Project for the Government's Purchase Service,China(13210186)
国家科技期刊平台
NSTL
万方数据