Umesh Acharya, Walster Hall, North Dakota State University, Fargo, ND and Amitava Chatterjee, North Dakota State University, North Dakota State University, Fargo, ND
Five different methods were compared as soil biological indicators from nine different location around Red River Valley of North Dakota and Minnesota. Seven different soil series were under study range in soil pH (5.98 to 8.60), soil organic matter (22.8 to 45.7 g kg-1), electrical conductivity (0.99 to 8.69 dSm-1), KCl extractable N (6.04 to 33.5 mg kg-1), Olsen Phosphorous (16.3 to 71.5 mg Kg-1). Soil health biological parameters such as infrared gas analysis soil respiration (IRGA), Alkali base trap of CO2, permanganate oxidizable Carbon (POXC), soil organic carbon (SOC), Chloroform fumigation extraction-microbial biomass carbon (CFMBC), Solvita gel system and Solvita labial amino-nitrogen (SLAN) of different soil samples were analyzed and significant result were observed. Correlation studies shows there CFMBC have significant correlation with other parameters such as Alkali base trap, Solvita gel, SLAN, POXC, SOC ranges (r=0.38 to 0.68) except IRGA. Regression study of microbial biomass C estimated by CFMBC as independent variable and alkali trap, solvita, SLAN, POXC and SOC separately as dependent variable in different soil series along Red river valley shows Solvita gel shows strongest significant correlation with CFMBC for Fargo soil series, POXC for Bearden, SOC for Elmville, Glyndon, Inkster and Alkali trap Wheatville soil series. This study shows CFMBC have significant correlation with other biological indicators and can be used to estimate carbon content in soil also different soil series are estimated best by various biological indicator.