Effect of different N fertilisation strategies on yield, plant N status, N uptake and soil characteristics in a maize-barley rotation

摘要

A field experiment was carried out to determine the effect of different strategies of N fertilisation on the maize-winter barley rotation. Five N managements were applied on a catch-crop of maize: mineral N, at 200 and 100 kg N ha~(-1); olive pomace compost plus mineral N (100 + 100 kg N ha~(-1)); olive pomace compost at 100 kg N ha~(-1); unfertilised control. The residual effects of the N treatments were evaluated in the following unfertilised winter barley crop. The results show that it is possibleto achieve good yields and high protein content and N uptake in both maize and barley crops when N fertiliser is partially substituted with an organic amendment, whereas the application of the organic waste as the only source of N is unsustainable fromthe agronomic point of view. Furthermore, the total organic carbon in the soil at the end of experiment increased with the application of organic N. At last, the N indicators (SPAD readings and nitrate concentration) allow us to obtain indications aboutthe plant N status, providing useful information for the eventual adjustment of N fertilisation during plant cycles.