Improving mineral nitrogen control by combining catch crops,fertilisation, and straw management in a clay loam soil

This experiment was conducted on a clay loam Cambisol and set out to determine the effects of combining catch crops, variable fertilisation levels, and straw management on the productivity of a spring barley-catch crop agrosystem, on the enrichment of soil with organic matter and nitrogen (N), and on soil mineral N control. Research was carried out in a spring barley (Hordeum vulgare L.) crop without catch crops, with undersown red clover (Trifolium pratense L.), and with post-crop white mustard (Sinapis alba L.). The barley was unfertilised, fertilised at moderate rates or at high rates. Straw was managed by either removing it from the field or chopping and spreading it. The quantity of organic matter and N incorporated into the soil depended on the fertilisation level of the barley crop. Soil mineral N stocks in the spring were reduced when straw was used together with red clover. When white mustard mass was incorporated alone in the autumn during ploughing, soil mineral N was reduced in the spring; however, when it was incorporated with straw, the effect was the opposite. Soil mineral N content is controllable when organic matter components are combined according to their decomposition rates, masses, and incorporation times.