The influence of biofertilizers and biologics on the fertility and productivity of gray-earth soils of the south-east of Kazakhstan

Abstract

The article presents the results of a study on the use of biofertilizers and biologics (biohumus, manure, HansePlant, BioEcoGum, Tumat and Agroflorin) on the indicators of fertility and productivity of gray-earth soils of the south-east of Kazakhstan. In the variants of biofertilizers and biologics, the increase in total humus compared to the control was 0.02-0.04 %. Increase of nitrate nitrogen, respectively (0.4-1.1 mg/kg), mobile elements of phosphorus (10.2-16.3 mg/kg), potassium (14.4-22.2 mg/kg) and sulfur (0.1-0.5 mg/kg). The use of biofertilizers and biological preparations has shown an improvement in the agro- and water-physical properties of the soil. Biofertilizers and biologics contributed to an increase in the quantitative and weight index of large nodules formed on the main root, where active nitrogen fixation occurs (12.2-19.0 pieces or 33.5-49.7 % of all formed nodules). The largest number of nitrogen fixators was also observed in soil samples with biofertilizers and biological preparations (from (9.2±1.3) ×106 to (14.8±0.7)×106). The introduction of biofertilizers and biologics increased the content of protein (34.71-34.92 %) and fat (29.50-30.78 %) in soybean plant samples. According to the content of heavy metals in soybean grain (Zn, Fe, Mn, Ni, Co), the indicators in these variants did not exceed the maximum permissible concentration. On average, in 2021-2022, a higher level (31.4-39.8 c/ha) of soybean grain yield was obtained on variants with biologization means. At the same time, the highest yield was obtained when treated with HansePlant – 39.8 c/ha, slightly lower than 35.2-38.6 c/ha (BioEcoGum and Tumat). On variants with the aftereffect of vermicompost and manure, respectively, 31.4 c/ha were obtained. With the yield under control - 24.2 c/ ha.