The biological activity and toxicity of soil, the defeat of grain crops by root rot in different crop rotations

doi: 10.30766/2072-9081.2014.43.6.37-44.

Pages: 37-44.

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Zamyatin S.А., PhD, Acting Deputy Director on scientific work
Mari Agricultural Research Institute, Yoshkar-Ola, Russia

Apaeva N.N., PhD, Associate Professor
«Mari state University», Yoshkar-Ola, Russia

E-mail: zamyatin.ser@mail.ru, apaevanina@mail.ru

It is found that the biological activity of the soil varies depending on the saturation of rotation crops in the rotation and the introduction of clover and potatoes. Application of manure for potatoes and frequent loosening the soil in the growing culture promotes active microbial activity. Under grain crops it were the smallest expansion of linen, which indicates a low microbial activity in the soil. Long-term studies have shown that the highest biological activity of the soil was in the rotation, where cultivated cereals, row crops and grasses. At saturation of crop rotation with cereals by 83% (grain crop rotation) microbiological activity of the soil decreases. Level of decomposition of linen depends on the application of mineral fertilizers and the amount of precipitation. The fewer rainfall the less linen is decomposed. At entering of mineral fertilizers biological activity of the soil increases. Correlation dependence of decomposition of linen from hydrothermal coefficient ranged from 0.82 to 0.92. Plowing chopped straw crops and aftergrowth clover in the first year reduces biological activity of the soil, but later there is a gradual increase in performance of degradation of linen cloth as compared with the conventional technique without the organic substance. The degree of susceptibility of crop root rot increases and the yield decreases with increasing the share of cereals in the rotation. In the first rotation disease was increased from 7.5 to 50.1%, and development from 2.1 to 15.3% in some years. Cultivation of clover significantly reduced the spread of root rot to 4.2%, the development of up to 1.1%. The smallest was the development of root rot in the fourth rotation, where cereals occupy 50%. Adding chopped of organic matter and of mineral fertilizers reduces infestation of crops root rots. Data analysis of toxicity of soil in field crop rotations showed that the highest soil toxicity observed in field crop rotations with high (83%) saturation of crops. The use of mineral fertilizers under field crops had almost no effect on the toxic condition of the soil. Analysis of correlation between toxicity and biological activity of the soil showed a close inverse correlation (r = -0.84).

Keywords: crop rotation, soil biological activity, toxicity, root rots, mineral fertilizers, organic technology