Study on the effect of different levels of organic and inorganic fertilizers on microbial enzymes and soil mesofauna in soybean ecosystem

Soybean [Glycine max (L.) Merril]. is also called Golden bean belongs to family Fabaceae is native to China having high nutritive value and oil content. Due to usage of inorganic fertilizers the fertility of soil and yield soybean has declined. Organic manures known to increase the soil fertility, structure and also influence the microbial enzymes activity and soil mesofauna. In this context thepresent investigation wasundertaken to study, the different dosesof farm yardmanureand chemical fertilizers on the soil mesofauna and microbial enzymes at GKVK, Bangalore during the year 2013–2014. The investigation revealed that higher abundance of soil mesofauna (18.53) was recorded in 20 tons of FYMha⁻¹ compared to the treatments with recommended package of practices (12.35) and inorganic fertilizer (10.30) alone. Soil mesofauna exhibited a significant positive relation with the microbial enzymes like dehydrogenase, acid and alkaline phosphtases and urease. The results of the multiple linear regression analysis showed that the influence of exchangeable calcium, available potassium and available phosphorous, exchangeable magnesium, dehydrogenase, alkaline phosphatase and urease on the abundance of soil mesofauna was up to 79 per cent. Higher rhizobium nodule number (64.93/plant) and yield (16.01 q/ha) of soybean found to increase with increase in farmyard manure application.