Soil Microbial and Biochemical Properties under Conservation Agriculture in rice-based cropping systems in lower Indo-Gangetic Plain of West Bengal

Soil microbial and biochemical properties in rice-based cropping systems within the lower Indo-Gangetic Plain of West Bengal were evaluated under conservation agriculture (CA) management practices. Research found that microbial and biochemical characteristics of soil respond more rapidly to management practices compared to chemical and physical attributes.

Although CA's impact on soil microbial properties is limited primarily to counting microbes, its effects on soil enzyme activities and microbial activity remain less documented. This study aimed to assess enzyme activities (dehydrogenase, beta-glucosidase, acid phosphatase, and alkaline phosphatase), microbial activities (nitrogen fixation, phosphate solubilization, and cellulolytic activities), microbial biomass (soil microbial biomass carbon and nitrogen), and nutrient availability in alluvial soil under CA.

The field experiment was conducted in a split plot design with three cropping systems (rice-maize-cowpea, rice-wheat-green gram, and rice-cauliflower-boro rice/summer rice), three tillage operations (conventional, minimum, and zero tillage), and three residue application levels (no residue, 50%, and 100%). Biological soil health index revealed that zero tillage (MT) and minimum tillage (ZT) treatments, along with 100% residue application (R100), demonstrated improved soil health compared to conventional tillage and 50% residue application.

Among cropping systems, rice-maize-cowpea and rice-wheat-green gram performed better than rice-cauliflower-boro rice/summer rice in terms of microbial and biochemical properties. The findings suggest that conservation agriculture can be employed as a sustainable practice to restore agro-ecosystem health and function.