Seasonal effect of green manure and phosphorus levels on soil parameters and their correlation in acid soils of Meghalaya

The present investigation was carried out at the experimental farm of College of Post Graduate Studies, CAU, Meghalaya in 2012 to study the seasonal effect on soil properties as influenced by green manure and phosphorus in acid soil. In summer, the experiment was conducted for baby corn (mays L.) with in situ green manuring of ricebean (umbellata L.) consisting of two levels i.e. without and with green manuring and three levels of phosphorus (P) i.e. 0, 30 and 60 kg PO ha supplied through single super phosphate. In, the baby corn was sown with 80 kg N, 40 kg PO and 40 kg KO. Bulk density (BD), porosity, organic carbon (OC), available nitrogen (N), P and soil microbial biomass carbon (SMBC), nitrogen (SMBN) and phosphorus (SMBP) were significantly influenced by green manure and phosphorus in summer. The residual green manure also enhanced the physical, chemical and microbial properties of the soil, but residual P had effect over available P only. Negative correlation existed between BD and porosity, OC, available N, P and microbial biomass in soil. Significant positive correlation (p<0.01) was found between OC and SMBC, N and SMBN, P and SMBP in summer and between N and SMBN (p<0.05) in. kharif Baby cob yield, fodder yield and harvest index were positively influenced by direct application of green manure and P levels. The highest yield of baby corn obtained with application of 60 kg PO ha was 3.64 and 2.58t ha in summer and kharif respectively. Yield in summer was significantly positively correlated (p<0.01) with all the soil properties except BD.