Long Term Resource Conservation Technologies Sustained Yield, Microbial Activities and Soil Physico-chemical Properties in Rice-green Gram Cropping System

Abstract

PurposeMicrobial communities in rhizospheric soil play a significant role in sustaining the soil quality and also recognized as key ecological indicators to assess the soil health. MethodsWe studied the long-term effects of resource conservation technologies on functional microbial diversity and their interactions with soil biochemical properties and enzymatic activities in tropical rice-green gram cropping system. The experiment included conventional practice (CC), brown manuring (BM), green manuring (GM), wet direct drum sowing (WDS), zero tillage (ZT), green manuring-customized leaf colour chart based-N application (GM-CLCC N) and biochar (BC) treatments. ResultsThe result revealed that microbial biomass nitrogen (N), carbon (C) and phosphorus (P) in GM practice increased by 23.3, 37.7 and 35.1%, respectively over CC. The Shannon index and McIntosh index were higher by 86.9% and 29.2% in GM as compared to conventional practice and significantly correlated with microbial biomass (C & P) and soil microbial populations whereas, Shannon index was positively correlated with the microbial biomass (C, N & P) and soil enzyme activities. Principal component analysis showed a significant separate cluster among the treatments amended with and without biomass addition. ConclusionsMoreover, dominance of carbon utilizing microbes in biomass amended treatments indicated that these could supply good amount of labile carbon sources on real time basis for microbial activity. Which may protect the stable carbon fraction in soil, hence could support higher build-up of carbon in long run and could offer sustainable yield under rice-green gram soil.