The influence of biological factors and mineral fertilizers on soil fertility, yield and feed quality in crop rotation in the North-West

In an improved five-field crop rotation on sod-podzolic soil (83% of arable land) in the conditions of the Novgorod region, three methods of using biofertilizers in the cultivation of forage crops on two backgrounds of mineral fertilizers and plowing straw by-products for fertilizer were studied. The double use of microbiological fertilizers Azotovite and Phosphatovite (pickling of seed material at 2 l/t and non-root spraying at 1 l/ha) when applying a complete mineral fertilizer to the projected harvest provided, on average, the best quantitative indicators of feed quality per rotation: productivity 6.0 thousand tons of feed units/ha; digestible protein 0.64 t/ha with a low energy consumption per thousand tons of feed units of 2.3 GJ and high energy efficiency of production above 5 units. The four-fold use of grain and leguminous straw as an organic fertilizer during rotation in crop rotation and the humification of crop and root residues increased the energy potential of the soil in all experimental variants by 45-96 GJ/ha.