Indian Journal of Agronomy

The field experiment was conducted at ICAR-Indian Agricultural Research Institute, New Delhi during rainy (kharif) season of 2017 to study the influence of different tillage practices and phosphorous management on productivity of soybean and soil properties in soybean-wheat rotation under conservation agriculture. The experiment was laid out in split plot design with three replications. Tillage and residues treatments were assigned in main plots which consisted of conventional tillage without residue (CT-R), zero tillage without residue (ZT-R), zero tillage with wheat residues @ 3 t/ha (ZT + R) and zero tillage-bed planting with wheat residues @ 3 t/ha (ZT-B + R) and phosphorus levels were assigned in sub-plots as basal application of 0, 40, 80, 120 kg P₂O₅/ha. The study revealed that higher seed yield was recorded in ZT-B + R (2.28 t/ha) and yield improvement with ZT-B + R was 16.2%, 11.0% and 5.3% compared to CT-R, ZT-R and ZT + R, respectively. ZT-B + R recorded the highest soil aggregate stabilty, soil organic carbon, microbial biomass carbon and dehydrogenase activity and it was statistically at par with ZT + R. Among the phosphorous management practices, basal application of 80 kg P₂O₅/ha, being at par with 120 kg P₂O₅/ha recorded significantly higher seed yield. Phosphorous management practices did not influence significantly the soil properties, however application of 80 kg P₂O₅/ha enhanced the biological activities of soil, viz. microbial biomass carbon (MBC) and dehydrogenase activity (DHA). Therefore, it was concluded that ZT-B + R and basal application 80 kg P₂O₅/ha is effective for improving soybean productivity and soil quality indicators in soybean-wheat cropping sequence under conservation agriculture.