Depth of nitrogen fertiliser placement affects nitrogen accumulation, translocation and nitrate-nitrogen content in soil of rainfed wheat

A field experiment was conducted to examine the effects of different depths ofnitrogen (N) fertiliser placements on N accumulation, remobilisation and NO3−-Ncontent in soil of rainfed wheat. Nitrogen was applied on the surface (D1) and inthe 10 cm (D2), 20 cm (D3) and 30 cm (D4) soil layers from 2010 to 2012.Compared with D1 and D2, D3 and D4 treatments obtained significant higher Ndistribution amounts in grain and N accumulation amounts at maturity. D3 and D4treatments increased the N accumulation amount of vegetative organs at anthesisand at maturity. D3 treatment resulted in significantly higher N translocationamounts from vegetative organs to grains compared with D1 and D2 treatments andhad no significant difference with D4 treatment. Compared with the D1 and D2, D3and D4 treatments obtained significant higher NO3−-N contents in the 20 cm to 120cm soil layer at anthesis from 2011 to 2012. However, D3 treatment showedno significant differences with D1 and D2 treatments at maturity in terms of theNO3−-N contents in the 40 cm to 100 cm soil layer. D4 treatment produced thehighest NO3−-N contents in the 40 cm to 140 cm soil layer. Grain yield, N uptakeefficiency, apparent N recovery efficiency, N agronomic efficiency and N partialfactor productivity were significantly increased by D3 and D4 treatments. Theseresults suggest that the D3 treatment facilitates the best wheat production andhighest efficiency among all treatments.

کلیدواژه ها:

Nitrogen fertiliser placement ، Nitrogen accumulation ، Nitrogen translocation ، Nitrate-nitrogen content ، Grain yield ، Rain-fed wheat