Assessing Soil Organic Carbon Fractions in a Soil Applied with Pig Slurry

Abstract

South African farmers have regarded the use of pig slurry (PS) as a method to sequestrate carbon (C) into the soil and subsequently increase soil productivity. The aim of this study was to assess C fractions and the correlation between the labile and non-labile C pools. Soil samples from 0 years of PS application (0 year), 3 years of PS application (3 years) and 10 years of PS application (10 years) were taken at the three depths of 0–10 cm, 10–20 cm and 20–40 cm and were analysed for both physicochemical properties and C fractions. 3 years had higher values of analysed chemical properties; C was more sequestered at the depth of 0–10 cm compared to other depths; and 10 years had more sequestered C as compared to 0 year and 3 years. Highest soil organic carbon (SOC), with the exception of particulate organic carbon (POC), was obtained under 10 years, which is attributed to the accumulation of PS over the years, therefore building recalcitrant material that can buffer the depleted. Thus, making short-term application of PS is recommended for the stabilization of chemical properties, and making long-term application of PS is recommended for the higher amount of C sequestration.