The influence of biologized fertilizing systems on the nutritional regime of gray forestal soil under the winter wheat

Abstract

The influence of biologized fertilizing systems on the changes’ patterns of the fertility elements of gray forestal soil under winter wheat were studied. The feasibility of using of the legume’s straw (peas or fodder beans) on the background of N₉₀P₆₀K₆₀ with the addition of humus fertilizer was established. This ensured a noticeable alkalization of the soil solution, in particular, an increase in exchangeable acidity by 0.2–0.3 units relative to the control. This was accompanied by an increase in the amount of absorbed bases to a level of 5.56–5.70 mg-eq/100 g of soil and a decrease in hydrolytic acidity. When using an increased dose of mineral fertilizers (N₁₅₀Р₁₂₀К₁₂₀) on the background of legume’s straw + humus fertilizer, a decrease in exchangeable acidity and, accordingly, a decrease in the amount of absorbed bases, as well as an increase in hydrolytic acidity to the level of 2.52 mg-eq/100 g of soil were noted. Plowing the by-products of the predecessor (legume’s straw), applying the mineral fertilizers at a dose of N₉₀P₆₀K₆₀, using bioeffectors (biostimulant – BS, humus fertilizer – HF) or treating crops with a chelate fertilizer (CF) contributed to an increase in the content of fertility elements in gray forestal soil. Namely, easily accessible forms of nitrogen, phosphorus, potassium. The highest provision of soil with easily hydrolyzed forms of nitrogen (12.9–14.5 mg/100 g of soil) was observed when using fertilizing systems consisting of legumes’ straw + N₉₀P₆₀K₆₀ + BS + HF and in the case of applying N₁₅₀Р₁₂₀К₁₂₀ + HF on the background of pea straw or fodder beans’ straw. Similar patterns of changes in the content of mobile forms of phosphorus and potassium were noted in the conditions of the indicated fertilizing systems. In the case of using HF as part of the fertilizing system legumes’ straw + N₉₀P₆₀K₆₀ + HF, the values of the content of nutrients (the corresponding forms of nitrogen, phosphorus and potassium) turned out to be closer to the variant using humus fertilizer. This indicates a partial decrease in the intensity and/or efficiency of plant use of basic nutrients under the conditions of the mentioned variant. It is obvious, that the introduction of biologization elements for the cultivation of winter wheat on the background of legumes’ straw + optimal dose of mineral fertilizers with appropriate bioeffectors can be promising measures to improve soil fertility.