TITLE:
Effect of Different Nitrogen Fertilizer Types and Application Measures on Temporal and Spatial Variation of Soil Nitrate-Nitrogen at Cucumber Field
AUTHORS:
Zhaopeng Ou Yang, Xurong Mei, Fan Gao, Yuzhong Li, Jiaxuan Guo
KEYWORDS:
Solar Greenhouse; Cucumber; Nitrate-Nitrogen; Nitrogen Retention
JOURNAL NAME:
Journal of Environmental Protection,
Vol.4 No.1,
January
29,
2013
ABSTRACT: Nitrate-nitrogen content of groundwater are ever-increasing in underneath
vegetable growing areas, in this paper, based on field test of cucumber
cultivated in Solar Greenhouse in North China, we study the effects of different
nitrogen fertilizer application levels (250, 300, 350kg/hm2) and different nitrogen
fertilizer types (urea, urea + nitrification inhibitor, slow-release fertilizer) on
temporal and spatial variation of soil nitrate-nitrogen content in different
soil depth, soil nitrogen fertilizer retention and nitrogen use efficiency
during cucumber growth period. The results show that, in the cases of nitrogen
fertilizer types (urea and urea + nitrification inhibitor), for surface soil (0 - 40 cm soil depth), the temporal trend of soil nitrate-nitrogen content
variation is similar: during the early stage of cucumber growth, soil nitrate-nitrogen
content is relatively high; during the middle stage of cucumber growth, as
nitrogen is constantly being absorbed by the vegetable, soil nitrate-nitrogen
content decrease; during the late stage of cucumber growth, soil nitrate-nitrogen
content increase, and increase more significantly when nitrification inhibitor
is added in the fertilizer. For deep soil layer (40 - 100 cm depth), when only using urea, the temporal trend of soil
nitrate-nitrogen content variation is that of continuous increase, when adding
nitrification inhibitor, the temporal trend of soil nitrate-nitrogen content
variation is that of insignificant increase. In the case of slow-release
fertilizer, for both surface soil and deep soil layer, the temporal trend of
soil nitrate-nitrogen content variation is that of continuous decrease. For all
three types of nitrogen fertilizer, as fertilization level increase, soil
nitrate-nitrogen content in various soil layers increase with it. In the case
of fertilization at 300 kg/hm2 and 350 kg/hm2, adding nitrification
inhibitor can increase soil retention of nitrogen fertilizer. This study
suggests that adding nitrification inhibitors can increase soil retention of
nitrogen fertilizer, decrease nitrate-nitrogen leaching downward, thereby
reducing the pollution to groundwater.