Effect of conservation agricultural practices and nitrogen management on soil properties

Abstract

A field experiment was carried out to evaluate the effect of conservation agricultural practices and nitrogen management on soil physical, chemical and biological properties after 2 years of continuous soybean (Glycine max L.) – wheat (Triticum aestivum L.) sequence. The experiment was conducted with 4 main plot treatments, i.e. Zero till without residue (ZT-R), Zero till with soybean residue (ZT+SR), Zero till with soybean and wheat residues (ZT+SWR) and Conventional till without residues (CT-R) and 4 sub plot treatments, i.e. 100% recommended dose of nitrogen (RDN) as basal (N1), 125% RDN as basal (N2), 100% + 25% top dressing (N3) and 75% basal + 25 % top dressing (N4). ZT+SWR recorded significantly higher soil organic carbon, microbial biomass carbon, and improved physical, chemical and biological properties compared to other treatments. ZT+SWR recorded 16.5 % and 25.9 % higher microbial biomass carbon than ZT-R and CT-R respectively. The same treatment also enhanced the available N, P and K in soil. Nitrogen management practices did not exert significant influence on soil properties, however, application of extra dose of nitrogen in residue added plots, enhanced the biological activity and thus improved the microbial biomass carbon, dehydrogenase activity and alkaline phosphatase activity which in turn contributed for better physical and chemical properties. Therefore, we conclude that ZT+SWR and 125% RDN as basal in conservation agriculture plots was found to be beneficial for improving soil health.

Keywords

• Conservation agriculture
• Residue
• Soil
• Soybean–wheat
• Zero tillage