Decomposition in the field of residues of oilseed rape grown at two levels of nitrogen fertilisation. Effects on the dynamics of soil mineral nitrogen between successive crops

Abstract

The decomposition of oilseed rape residues of different quality and its effects on the mineral N dynamics of the soil in the period between crops were studied in situ. The residues studied were obtained by growing an oilseed rape crop at two levels of N fertilisation, 0 and 270 kg N ha-1. The study was carried out using two types of experiment: field plots and cylinders filled with disturbed soil and inserted into the soil. The decomposition of the residues was followed using an approach involving the dynamics of both carbon and nitrogen, the parameters measured being the CO2 emitted from the soil, the soil mineral N content, the C present in soluble form or in the form of microbial biomass, and the C and N present in the form of plant residues.