Combined Application of Rhizobium sp. MR-14 and Phosphate Solubilizing Bacteria Bacillus cereus NE-10 in Mungbean ( Vigna radiata L.) Improves Plant Growth and Yield of Succeeding Wheat ( Triticum aestivum L.) and Soil Chemical and Biological Properties

Abstract

Microbial inoculants, mainly Rhizobium spp. and phosphate-solubilizing bacteria (PSB), have emerged as promising biofertilizers in sustainable agriculture. This study evaluated the contributions of co-inoculating mungbean (Vigna radiata L.) with Rhizobium sp. MR-14 (Mesorhizobium) and PSB Bacillus cereus NE-10 on productivity and soil health in mungbean-wheat (Triticum aestivum L.) crop sequence. The Dual inoculation of Rhizobium sp. MR-14 and PSB Bacillus cereus NE-10 in mungbean led to an increase of grain yield by 9.2%, with increases of 11.7, 4.9, 8.9, and 2.2% in mungbean grain yield over the uninoculated control, MR-14 alone, NE-10 alone, and the recommended dose of fertilizer (RDF), respectively. This treatment resulted in the availability of nitrogen (N), phosphorus (P), and potassium (K) in soil of 18.8, 57.2, and 18.7%, respectively, at harvest in comparison to the uninoculated mungbean. In the succeeding wheat crop, this treatment resulted in 9.7 and 9.4% higher grain and straw yields, respectively, regardless of N fertilizer levels. Furthermore, co-inoculation in the preceding mungbean crop increased grain and straw yields by 4.2 and 4.4% over MR-14 alone, 2.8 and 3.2% over NE-10 alone, and 6.3 and 7.0% over the RDF treatment, respectively. Dual inoculation treatment also improved soil fertility by resulting in significantly more N availability of 15.6% at 75 days and P availability of 28.4% and 54.2% at 45 and 75 days, respectively, during the wheat growth period. Soil biological activities were also notably enhanced during the wheat phase. Our findings suggest that integrating Rhizobium sp. MR-14 and Bacillus cereus NE-10 biofertilizers in mungbean cultivation also contributes to enhance the productivity of subsequent wheat crops and soil chemical and biological properties, thereby contributing to more sustainable and cost-effective agricultural practices.