Relationship between rate of crop growth at date of fertiliser N application and fate of fertiliser N applied to winter wheat |
| |
Authors: | Limaux François Recous Sylvie Meynard Jean-Marc Guckert Armand |
| |
Affiliation: | (1) Chambre Régionale d'Agriculture de Lorraine, rue de la Vologne, 54524 Laxou cedex, France;(2) Unité d'agronomie, rue Fernand Christ, INRA, 02007 Laon cedex, France;(3) Unité d'agronomie, INRA-INA P-G, BP 01, 78850 Thiverval-Grignon, France;(4) Unité Agronomie et Environnement, ENSAIA, 2 avenue de la Forêt de Haye, 54505 Vandoeuvre-lès-Nancy, France |
| |
Abstract: | To investigate the relationship between the timing of fertiliser N applications and the N use efficiency of wheat, three field experiments with 15N were set up on winter wheat, on three different soils in France. Different crop N demands on the day of fertiliser application were obtained by varying either crop densities or date of fertiliser application. Labelled 15NH4 15NO3 was applied at tillering and during stem elongation. The 15N recovered from plant and soil at different dates after 15N addition and at maturity of wheat was measured. The fate of fertiliser N was rapidly determined, most of the fertiliser N accumulated in the wheat at maturity having been taken up within a few days of application. 15N recovery by the crop at final harvest (%) varied greatly (19–55% N applied) according to crop density, soil type and date of application. It was linearly related to the instantaneous crop growth rate calculated at the day of 15N application. The amount of fertiliser N immobilised in the soil was constant at 20 kg N ha−1, for all soil types and crop densities. Because residual mineral 15N in the soil at harvest was negligible and immobilisation was constant, the level of total 15N measured in the different N pools (soil+plant) reflected the% 15N uptake by the plant. There was consequently a negative linear relationship between the percentage of 15N not recovered for measurement, and crop growth rate (i.e. crop N demand) at date of fertiliser application. These results suggest that crop N demand at the time of N application determines the ability of the crop to compete for N with other processes, and may be a major factor determining the division of N between soil and crop. This revised version was published online in June 2006 with corrections to the Cover Date. |
| |
Keywords: | date of application fertiliser growth rate N uptake efficiency 15N winter wheat |
本文献已被 SpringerLink 等数据库收录! |
|