Effect of Long-Term Regular Application of Fertilizers on Main Parameters of Soil Fertility and Productivity of Fodder Crop Rotation on Deeply Freezing Meadow-Chernozemic Soil of Transbaikalia

Resumo

New experimental data on changes in organic matter content, in soil nutrition regimes, and in productivity of crops in fodder rotation were obtained. Long-term (1995–2005) studies of the effect of different rates of mineral and organic-mineral fertilizers (the control variant without fertilizers; N₁₂₀Р₉₀К₉₀; manure 40 t + N₁₂₀Р₉₀К₉₀; N₂₄₀Р₁₈₀К₁₈₀; and manure 80 t + N₂₄₀P₁₈₀K₁₈₀) in the fodder crop rotation (fallow–turnip–corn–sunflower mixture–spring rape–pea–oats mixture) were performed at the Research Institute of Veterinary Science of Eastern Siberia, Siberian Federal Scientific Center of Agro-Bio Technologies, Russian Academy of Sciences. Their results are discussed in this article. The application of particular norms of organic fertilizers per rotation (80 t of manure and N₂₄₀P₁₈₀K₁₈₀ kg of active substance) resulted in the greatest rise in the nitrate content (by 10–28 mg/kg), available phosphorus (by 21–47), exchangeable potassium (by 12–57 mg/kg of soil), and in organic matter (by 0.08% over the first rotation, by 0.09% over the second one, and by 0.17% over two rotations) in the 0- to 20-cm layer. Productivity of fodder crop rotation increased by 55.4–98.8% over the first rotation and by 58.4–120.6% over the second one.