Вплив систем удобрення на запаси сполук азоту в дерново-підзолистих ґрунтах

Abstract

The purpose. To assess influence of different fertilizer systems on change of nitrogenous regime of sod-podzolic sandy loam soil in short-term field crop rotation. Methods. Field — stationary experiments, laboratory — determination of the content of nitrogen of easy hydrolyzable joints according to Cornfield, nitrate and ammonium — using ionometer method, mathematical-statistical analysis. Results. Influence is considered of organic, mineral fertilizers and their combination on dynamics of nitrogen of easy hydrolyzable and mineral joints in sod-podzolic soil. Analysis, assessment are realized, and dependence of changes of the content of accessible joints of nitrogen on sort of fertilizers is gained. It is established that the highest stores of nitrogen of easy hydrolyzable joints during vegetation at organic fertilizer system (dung — 20 t/hectare — average during crop rotation) on the average for 2012–2014 were 330 kg/hectare, that in 2,7 times above, than in control, or in 1,4–1,9 times above, than at other fertilizer systems. The share of mineral nitrogen from nitrogen of easy hydrolyzable joints increases from 12% in control almost up to 30% at importation of dung in dose of 20 t/hectare, that considerably improves nitrogenous regime of sod-podzolic sandy loam soil and nitrogen nutrition of plants. Conclusions. Stores of mineral nitrogen and nitrogen of easy hydrolyzable joints depend on sort of fertilizer and speed of its transformation in soil. More mineral nitrogen was accumulated in soil at organic fertilizer systems (dung — 20 t/hectare) and at use of combination of dung and green manure crop — from 15 up to 66 kg/hectare, or more than in 4 times. The highest stores of nitrogen of mineral joints on phases of growth of potato were at importation of fertilizers on green manure crop — 60-99 kg/hectare, dung — 20 t/hectare — 57–96, and at the combined system — dung together with fertilizers — 51–84 kg/hectare. Increase of share of joints of mineral nitrogen testifies to intensity of processes of molding of organic substance in soil, and at absence growing plants — about an opportunity of vertical migration of mineral nitrogen and increase of ecological load of region.