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

Abstract

<span>A field experiment was conducted to examine the effects of different depths of<br /><span>nitrogen (N) fertiliser placements on N accumulation, remobilisation and NO<span>3−<span>-N<br /><span>content in soil of rainfed wheat. Nitrogen was applied on the surface (D<span>1<span>) and in<br /><span>the 10 cm (D<span>2<span>), 20 cm (D<span>3<span>) and 30 cm (D<span>4<span>) soil layers from 2010 to 2012.<br /><span>Compared with D<span>1 <span>and D<span>2<span>, D<span>3 <span>and D<span>4 <span>treatments obtained significant higher N<br /><span>distribution amounts in grain and N accumulation amounts at maturity. D<span>3 <span>and D<span>4<br /><span>treatments increased the N accumulation amount of vegetative organs at anthesis<br /><span>and at maturity. D<span>3 <span>treatment resulted in significantly higher N translocation<br /><span>amounts from vegetative organs to grains compared with D<span>1 <span>and D<span>2 <span>treatments and<br /><span>had no significant difference with D<span>4 <span>treatment. Compared with the D<span>1 <span>and D<span>2<span>, D<span>3<br /><span>and D<span>4 <span>treatments obtained significant higher NO<span>3−<span>-N contents in the 20 cm to 120<br /><span>cm soil layer at anthesis from 2011 to 2012. However, D<span>3 <span>treatment showed<br /><span>no significant differences with D<span>1 <span>and D<span>2 <span>treatments at maturity in terms of the<br /><span>NO<span>3−<span>-N contents in the 40 cm to 100 cm soil layer. D<span>4 <span>treatment produced the<br /><span>highest NO<span>3−<span>-N contents in the 40 cm to 140 cm soil layer. Grain yield, N uptake<br /><span>efficiency, apparent N recovery efficiency, N agronomic efficiency and N partial<br /><span>factor productivity were significantly increased by D<span>3 <span>and D<span>4 <span>treatments. These<br /><span>results suggest that the D<span>3 <span>treatment facilitates the best wheat production and<br /><span>highest efficiency among all treatments.</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><br /><br class="Apple-interchange-newline" /></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>