期刊
NUTRIENT CYCLING IN AGROECOSYSTEMS
卷 82, 期 2, 页码 187-196出版社
SPRINGER
DOI: 10.1007/s10705-008-9180-4
关键词
Soil nitrate-N; Optimum N management; Environmental contamination; High yield; Summer maize
类别
资金
- Key Project of Eleventh Five-year National Plan [2006BAD10B03, 2006BAD10B08]
- National Natural Science Foundation of China [30700478]
- Program for Changjiang Scholars and Innovative Research Team in University [IRT0511]
High profile nitrate-nitrogen (N) accumulation has caused a series of problems, including low N use efficiency and environmental contamination in intensive agricultural systems. The key objective of this study was to evaluate summer maize (Zea mays L.) yield and N uptake response to soil nitrate-N accumulation, and determine soil nitrate-N levels to meet N demand of high yield maize production in the North China Plain (NCP). A total of 1,883 farmers' fields were investigated and data from 458 no-N plots were analyzed in eight key maize production regions of the NCP from 2000 to 2005. High nitrate-N accumulation (>= 172 kg N ha(-1)) was observed in the top (0-90 cm) and deep (90-180 cm) soil layer with farmers' N practice during maize growing season. Across all 458 no-N plots, maize grain yield and N uptake response to initial soil nitrate-N content could be simulated by a linear plus plateau model, and calculated minimal pre-planting soil nitrate-N content for maximum grain yield and N uptake was 180 and 186 kg N ha(-1), respectively, under no-N application conditions. Economically optimum N rate (EONR) decreased linearly with increasing pre-planting soil nitrate-N content (r(2) = 0.894), and 1 kg soil nitrate-N ha(-1) was equivalent to 1.23 kg fertilizer-N ha(-1) for maize production. Residual soil nitrate-N content after maize harvest increased exponentially with increasing N fertilizer rate (P < 0.001), and average residual soil nitrate-N content at the EONR was 87 kg N ha(-1) with a range from 66 to 118 kg N ha(-1). We conclude that soil nitrate-N content in the top 90 cm of the soil profile should be maintained within the range of 87-180 kg N ha(-1) for high yield maize production. The upper limit of these levels would be reduce if N fertilizer was applied during maize growing season.
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