Dynamics of humus and macronutrients in soil depending on soybean fertilization

Abstract

The comparative assessment of the straw-litter compost (20 t/ha), ammonium nitrate (30 kg/ha N) and micro-fertilizer Azosol 36 Extra effect on soybean productivity and soil fertility in the southwestern part of the Chernozem region was carried out. Three years research found that using compost led to the positive balance of soil humus and macronutrients, increased yield and protein harvesting. The highest value of the soil organic matter net-balance was observed under using compost with ammonium nitrate – 0,52-0,68 %. In addition to this variant, the increase in easily hydrolyzed nitrogen in the soil was due to the combined use of mineral fertilizers – from 3.3 to 8.2 mg/kg. The transfer by grouping to a higher supply class in terms of both mobile phosphorus (163-196 mg/kg) and exchangeable potassium (125-168 mg/kg) was associated with the action of compost, which contributed to increasing the element content by 36-47 mg/kg and 5,4-43 mg/kg, respectively. It was likely that the productivity of the early-ripening soybean variety Lancetnaya was due to the nitrogen assimilation mainly from mineral fertilizers, while the mid-ripening variety Belgorodskaya 48 was more responsive to the compost using. The complex application of organic and mineral fertilizers for soybeans provided the highest yield regardless of the soybean variety (3 t/ha) and the positive dynamics of typical chernozem indicators.

The balance of organic matter and soil nutrients, depending on fertilization level of soybean varieties

“…It can be assumed that the microelement fertilizer contributed to the additional mobilization of nutrients from soil organic matter. This could be a consequence of both the increased soybean yield and the increased activity of the symbiotic apparatus, which was noted in the Azosol application variants [11,21]. Varietal specificity in relation to the of soil organic matter was manifested in the fact that its positive value in the cultivation of mid-ripening variety Belgorodskaya 48 was preserved only in the variants of compost application, and its joint use with ammonium nitrate in two-and three-component fertilizer -0.25-0.82%.…”