Soil enzymatic activity and chemical attributes after continuous and interrupted application of pig slurry

Abstract

The objective of this work was to evaluate enzymatic activities and chemical attributes of a soil under continuous application for 28 years and after interruption for 5 and 12 months of pig slurry (PS). The soil received doses of 0, 30 and 60 m3 ha-1 year-1 of PS since 1988, and in 2016, the plots were divided in half and there was interruption of the application of PS in half plot, generating a 2 × 2 factorial scheme, being two doses of PS (30 and 60 m3 ha-1 year-1) and two application conditions (continuous or interrupted). The available P, total organic carbon (TOC), pH, Al3+, H+ + Al3+, Ca2+, Mg2+ and K+ and activity of the enzymes arylsulfatase (AR), ?-glycosidase (?-G), acid (AP) and basic (BP) phosphatase , hydrolysis of fluorescein diacetate (FDA) of soil were assessed. The content of P, Mg2+ and H+ + Al3+ varied with the doses of PS applied, but not with the interruption of the applications. The continuous application of PS increased the activity of the enzymes AR, ?-G and BP, whereas FDA and AP were not influenced by the interruption of the applications. The interruption of PS application for up to one year did not change the chemical attributes of the soil, but reduces the activity of the enzymes AR, ?-G and BP.