Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6374910 | Field Crops Research | 2015 | 12 Pages |
Abstract
Eleven field trials of wheat (Triticum aestivum) in Yongshou County, Shaanxi Province and seven in Luoyang District, Henan Province were conducted with two treatments (without N as control and with 150Â kg NÂ haâ1 addition). Soil nitrate N and ammonium N concentrations were determined in five layers from 0 to 100Â cm depth at each site. Results showed that soil ammonium concentrations were very low and concentrations and cumulative amounts had no relations with wheat yield and yield increase by N applications. Nitrate N concentrations, in contrast, were high and correlated with seed (grain) and biomass yields of wheat without added N, and with yield increase by N addition in some layers. The cumulative nitrate N in 0-20Â cm layer plus other layers to different depths was significantly or very significantly correlated with control yield and yield increase by N addition. The cumulative nitrate N in 0-80Â cm depth explained 70% of seed yield, and that in 0-100Â cm 72% shoot variation and over 55% yield increases. Nitrate N occupied 88% of the total amount of ammonium N and nitrate N, and had the same trends as the total in reflecting soil N supplying capacity. Wheat mainly depended on 0-20Â cm layer nitrate N at over-wintering stage, 0-40Â cm at reviving, 0-60Â cm or deeper at elongation stages, and at maturity, the correlation of cumulative nitrate N in 0-100Â cm layer was highest with biomass and biomass increase by N addition. The control wheat in Yongshou County absorbed 107.4Â kg NÂ haâ1 from soil on average, equivalent to 72% of the cumulative nitrate N or 65% of the total mineral N in 0-100Â cm layer. After wheat harvest, the concentration of ammonium N was not significantly different from the initial while that of nitrate N greatly decreased.
Related Topics
Life Sciences
Agricultural and Biological Sciences
Agronomy and Crop Science
Authors
Y,-F. Miao, Z,-H. Wang, S,-X. Li,