Effect of liquid bioinoculants and straw mulch on health of Vertisols and productivity of soybean (Glycine max)

Abstract

Now-a-days use of machinery for crop harvesting leave behind large quantities of crop residues, which is burnt by farmers as cheap and easiest method with misconception that, burning of crop residues enhances soil fertility and helps in control weeds, insects and pests. The burning of crop residues result in heavy loss of soil nutrients emits large amount of submicron aerosols and trace gases and smoke, thereby posing problem to environment and human health hazards. Therefore, a field experiment was carried out during kharif season of 2019 at Research Farm, College of Agriculture (RVSKVV), Indore, India to study the effects of liquid bio-inoculants and wheat straw mulch on yield attributes, productivity and nutrient content of soybean grown in Vertisols. The soil of experimental site was clay loam in texture and alkaline in reaction (pH 7.8). The treatments were laid out in RBD in three replications with ten treatments. Among the various treatments, significantly higher yield parameters were recorded in Rhizobium+ PSB + wheat straw mulch @ 5.0 t/ha + foliar spray of PGPR @ 20 ml/L water at 35 DAS and flowering stage as compared to other treatments. Similarly, highest seed yield (12.32 q/ha) and biological yield (27.68 q/ha) was also recorded with the application of Rhizobium+ PSB + wheat straw mulch @ 5.0 t/ha + foliar spray of PGPR @ 20 mL/L water at 35 DAS and flowering stage. The higher nutrients content (N, P, and K in seed and straw) and their uptake; and available N content (262.67 kg/ha) and P content (12.27 kg/ha) in soil were observed under Rhizobium+ PSB + wheat straw mulch @ 5.0 t/ha + foliar spray of PGPR @ 20 mL/L water at 35 DAS and flowering stage in comparison to other treatments. Hence, dual seed inoculation, foliar spray of PGPR along with wheat straw mulch was found promising with higher productivity of soybean under Vertisols.