The influence of a production system and nitrogen fertilization rate on economical and ecological parameters of arable crops in a three‐year crop rotation

Abstract

In two long‐term static experiments (Central and NE Slovenia) the interaction between four different intensities of N fertilization and three different methods of organic fertilization (straw, manure and control without organic manure) was examined. The results showed that the income per hectare cannot be a good indicator of the economical effect of mineral and organic fertilizers. The calculation of cover per hectare gives more precise results. In the situation when the prices of agricultural produces become lower and lower and material expenses raise the great importance is attached to the aimed fertilization for higher cover. In the study the difference between the cover at the maximal yield and the cover at the maximal cover was 40 ‐107 DEM/ha. The farmyard manure mineralization is much quicker in Rakičan than in Jable. The reachable maximal yield of arable crops in the rotation in Jable is higher in the straw system but in Rakičan better results are achieved in the manure system. The criteria of sustainable managing and satisfactory cover correspond to the Nl mineral fertilization intensity in both systems of organic fertilization (manure and straw); namely, 73 kg/ha of mineral N and 50kgN/ha from manure in the manure system and 93 kg mineral N/ha in the straw system. In Nl the cover per kg N in Jable is 3.8 DEM in the manure system (farms with cattle) and 4.4 DEM in the straw ploughing under system; in Rakičan it is 1.4 DEM in the manure system and 2.8 DEM in the straw ploughing under system.