Abstract

                                Field investigations were conducted to assess the effect of conservationagricultural practices on soil biological properties and yield of cotton duringthe kharif season of 2018 and 2019. The experiments were laid out in asplit plot design with four main factors viz., conventional tillage with irrigationschedule of 0.8 IW/CPE ratio (M1), conventional tillage with irrigationschedule of 0.6 IW/CPE ratio (M2), minimum tillage with irrigation scheduleof 0.8 IW/CPE ratio (M3) and minimum tillage with irrigation schedule of0.6 IW/CPE ratio (M4). Sub plot had six treatments of weed and nutrientmanagement viz., crop residue mulch with 100% RDF (S1), crop residuemulch with 75% RDF (S2), pre-emergence application of pendimethalinfb one hand weeding with 100% RDF (S3), pre-emergence application ofpendimethalin fb one hand weeding with 75% RDF (S4), mechanical weedingtwice with 100% RDF (S5) and mechanical weeding twice with 75% RDF (S6).Total microbial populations viz., bacteria, fungal, and actinobacteria werehigher in cotton rhizosphere soil with the minimum tillage of irrigation at0.8 IW/CPE ratio (M3) in the main plot treatments. Cotton rhizosphere soilwith crop residue mulch with 100% RDF (S1) recorded a higher microbialpopulation and it was statistically similar with pre-emergence applicationof pendimethalin fb one hand weeding with 100% RDF (S3) in the subplot treatments. Among the treatment combination, minimum tillage withirrigation at 0.8 IW/CPE ratio (M3) and crop residue mulch with 100% RDF(S1) recorded a higher microbial population. Similarly, a higher seed yieldof cotton was also recorded with minimum tillage and irrigating the crop at0.8 IW/CPE ratio and pre-emergence application of pendimethalin fb onehand weeding along with application of 100% RDF (M3S3).

Key words : Conventional tillage; Conservation agriculture; Minimum tillage; Mulch