Fig. 2 Scatter plot of the microbial biomass versus the amino sugar content in conventional () and no-tillage (•) soils at Mandan, ND, Stratton, CO, Bushland, TX, Sidney, NE, Manhattan, KS, and Lexington, KY. Mean values with standard errors are shown, n = 3. The solid line represents the functional relation between both sets of parameter with its slope and its intercept