Effectiveness of the biodestructor action on the decomposition of rice residues in soybean cultivation technology

Abstract

For the implementation of productive potential of soybeans, it was presented an effective method of post-harvest residue destruction with the biologics in rice crop rotation. The research was conducted at the Institute of Rice of NAAS during 2016–2018. In autumn, post-harvest rice residues were treated with the Biocomplex-BTU Ecostern biodestructor (1l/ha) in combination with carbamide (concentrated amide water-soluble fertilizer) (30 kg/ha). The variant with the carbamide application (30 kg/ha) in autumn was a control. The application of the Biocomplex-BTU Ecostern biodestructor (1 l/ha) in combination with car-bamide increased the total number of pathogenic and saprotrophic fungi in the soil from 65.5 to 80.5 thou-sand/g of soil, or 22.9 %. Thus, the pathogenic microflora content in the studied variant was lower than in the control (carbamide application at rate of 30 kg/ha) by 21.8 %, and the number of saprotrophs increased 3.3 times. When Ecostern biodestructor and carbamide were combined for application, the number of antagonistic fungi doubled, while the number of toxin-forming fungi reduced by 9.4 %. Soybean yield at the combined application of Ecostern biodestructor and carbamide increased by 0.6 t/ha, or 17.9 % compared to the control (carbamide – 30 kg/ha). In addition, in this variant, the content of post-harvest rice residues in the soil at the soybean sowing was lower by 1.25 g/kg of soil, or 20.3 % compared to the control, which created favorable conditions for seed germination. It was observed that the yield increased due to the higher plant density and the number of beans per plant. Before harvesting, the soybean plant density due to the high field germination of seeds in the studied variant was 45 pcs/m2, which is 9.7 % more than the control (41 pcs/m2). The number of beans was 24 and 28 pcs/plant, and exceeded the control by 16.7 %; the thousand grain weight was 156.2 and 157.5 g which is more than the control by 0.8 %. Key words: post-harvest residues, microorganisms, fertilizers, soil, rice, soybeans, grain yield, thou-sand grains weight.