Working out of field crop rotations at various levels of intensification of agriculture in Kirov region
Results of researches spent in long stationary experiment on studying of various types of field crop rotations (24 schemes) are presented in the article. Crop rotations were studied under conditions of various intensification of crop farming (1982-2009). In crop rotations with grain crops saturation up to 83.4% toxicity of soil raised on 28.5%; cellulose-destruction activity of microorganisms decreased; and choking of crops increased on 11.4-75.1%. Without entering of organic fertilizers the humus content per rotation did not change; negative balance was created at a decrease of humus on 0.06-0.08 t/ha. Productivity of the grain decreased on 0.16-0.26 t/ha. At introduction of perennial and annual legume grasses, green manure species in crop rotations the amount of water durable aggregates increased by 6.7-11.7%. Manure entering promoted increase of soil structure. Activity of cellulose-destructing microorganisms raised after clovers in 1.2-2.0 times, the soil was non-toxic. The choking of crops decreased on 38.5-67.8%. Increasing of humus content occurred at entering of manure at rate 10 t/he; at sowing of green manure species (clover, melilot, annual grasses) humus balance was positive with accumulation on 1.14-1.26 t/ha. Productivity of crop rotations with occupied and green manure fallows increased by 15.8-35.6% in compare with pure fallow with entering of manure.
Keywords: crop rotations, soil fertility, a phytosanitation condition, productivity of crop rotations