Effect of Bacillus subtilis, Vermicompost and Phosphate Fertilizer on Microbial Biomass Nitrogen in Soil Planted with Cauliflower (Brassica oleracea var. botrytis)

Abstract

Abstract This study showed the effect of adding Bacillus subtilis, Vermicompost and phosphate fertilizer on microbial biomass nitrogen in the soil of cauliflower roots in flowering and full maturity stages. The experiment was carried out in a farm in the city of Al-Daghara sub-district, Al-Qadisiyah Governorate - Iraq, using a randomized complete block design with three replications. Bacillus subtilis, code for B1, and Vermicompost were added at levels (0, 10, and 20 t. ha-1), with the symbol V0, V1, and V2, respectively, and phosphate fertilizers at levels (0, 50, and 100 kg ha-1) with the symbol P0, P1, and P2, respectively. Fertilizer additions recorded significant values of microbial biomass nitrogen during the flowering and full maturity stages, which are the lowest in the full maturity stage due to the low activity of microorganisms and roots. It was found that the addition of bacteria, vermicompost and phosphate fertilizer. They work to increase nitrogen from the microbial biomass, either directly by increasing the activity of microorganisms and root cells, or by increasing the proportions of organic nitrogen added to the soil.