The role of biological means in organic agriculture

The paper shows the relevance of following the principles of an organic farming system to obtain environmentally friendly products and environmental protection. One of the important elements of organic farming is scientifically substantiated crop rotation, which ensures soil fertility. Based on the data of long-term research in the Republic of Kazakhstan, it is established that field crops, due to their biological characteristics and depending on the technological methods applied, leave different amounts of root and crop residues in the soil. According to the degree of soil enrichment with organic matter, the crops are arranged in the following sequence (in decreasing ability to structure formation): perennial legumes, winter grains, corn for grain, annual legumes, spring grains and sugar beets. The most favorable effect on light chestnut soils under irrigation conditions in the South-East of Kazakhstan is exerted by alfalfa, which accumulates up to 17 t/ha of root residues in the arable layer of soil containing more than 300 kg/ha of nitrogen, 80 kg/ha of phosphorus and 120 kg/ha of potassium. When straw 2 t/ha + manure 20 t/ha and mineral fertilizers N 20 P 60 K 60 were applied jointly on irrigated light chestnut soils in the South-East of Kazakhstan, the humus content increased by 0.30-0.39% compared to the control (without fertilizers). An increase in the amount of humus (0.61–0.70%) was observed when using straw 2 t/ha + fertilizers N 20 P 30 K 30 with green manure plowed in. In the dark chestnut soils of Western Kazakhstan, the application of 80 t/ha of manure per one rotation of a five-course grainfallow crop rotation increased the humus content by 0.23%, or 5.3 t/ha, compared to the control. The use of organic farming elements ensures a deficitfree balance of humus in the system of soil organic fertilizers – plant.