De-inking paper sludge requirement of liming high acidic potato soil

Abstract

Biosolids from de-inking processes are increasingly being used in Quebec (Canada) to improve acid soil. The objective of this study is to determine the optimum rates of de-inking paper sludge (DPS) for attaining target soil pH values of 5.2 and 5.5 for potato grown on podzolic soil. Incubation experiment was conducted during 18 weeks with a coarse textured soil (pH 4.8) and increasing rates of CaCO3 or DPS. Results indicate that the amounts of DPS required varied from 4.0 to 8.2 dry Mg DPS ha-1 for attaining pH 5.2 and from 7.6 to 15.2 dry Mg DPS ha-1for attaining pH 5.5. The required amount of DPS is proportional to its total CaCO3 equivalent