Contribution of soluble and insoluble fractions of agricultural residues to short-term pH changes

Abstract

The retention of agricultural residues in cropping systems to maintain soil fertility is also important for the redistribution of alkalinity. In systems that adopt minimum or no-tillage practices residue incorporation into the soil may occur slowly and the contribution of soluble and insoluble residue fractions to pH change may vary temporally and spatially. In this study we examined the contribution of whole, water soluble (70°C for 1 hour for two cycles) and insoluble fractions of canola, chickpea and wheat residues (added at 10 g kg-1 soil) to pH change in a Podosol (Podzol; initial pH 4.5) and a Tenosol (Cambisol; initial pH 6.2) over a 59-day incubation period. Whole residues increased ..