Studying the effect of organic matter recycling combined with mineral n fertilization in long-term field and model pot experiments: Untersuchung der wirkung der rezyklierung der organischen substanz kombiniert mit mineraldüngung in dauerfeldversuchen und modellgefässversuchen

Abstract

The effect of various combinations of organic and mineral N fertilizers was studied on the organic matter content of the soil, grain yield, dry matter production and N-uptake of maize. In a model experiment, large pots were filled with 55 kg sandy loam soil originating from the plots of the ‘International Long-term Experiments for Investigating the Effect of Organic and Inorganic Fertilisers’ (IOSDV), Keszthely. The field experiment, which was set up in 1983, contained three crop-rotations with maize, winter wheat and winter barley. Treatments: (1) inorganic fertilizers only with increasing N-doses (N); (2) farmyard manuring (FYM) in every third year+N; (3) stalk, straw or green manure+N. Our results clearly proved the advantage of organic matter recycling combined with mineral fertilization over treatment 1. In the fifth and sixth rotations, both types of organic matter recycling resulted in significantly higher Corg contents compared to mineral N fertilization without farmyard manuring or incorporation of crop residues. Grain yields in the field trial were the lowest in treatments without organic matter recycling. In the pot experiment, dry matter production and N accumulation in the grains and vegetative plant parts were also significantly higher in treatments where mineral fertilization was combined with organic matter recycling.