Influence of land use types on the distribution of soil organic carbon at different soil depth in the University of Cape Coast Teaching and Research Farm

Abstract

Soil organic carbon (SOC) is the principal component of soil organic matter and it is broadly considered as a central indicator of soil quality due to the numerous roles it plays in physical, biological and chemical processes of soil. The study sought to evaluate the influence of different land use types on the distribution of SOC at different depth in the University of Cape Coast Teaching and Research Farm. A stratified random sampling technique was used to collect 180 soil samples at 0-15 cm, 15-30 cm and 30-45 cm depths from arable, fallow, pasture and plantation land use systems within the 24.52 ha study site. Standard laboratory methods were used for analysing the selected physico-chemical properties. Descriptive statistics and relationships among soil properties at soil depths and land use types were generated using Minitab 19. The results of the study showed that land use systems significantly affected the distribution of SOC content, including the other properties at different soil depths. Adapting land quality classification using organic carbon content as a measure was in the order of plantation (2.57 %) > arable (1.99 %) > pasture (1.55 %) > fallow (1.14 %). Plantation field is the most sustainable type of land use as it promotes the retention of organic carbon in soil in contrast to the other land use types and may therefore be adopted as a strategy to restore degraded lands. Soil organic carbon content, as well as most of the other properties, was generally concentrated within the top layers but decreased with depth. A positive correlation was established between SOC and many soil properties, so managing SOC will equally improve the availability of these nutrients towards sustainable agriculture.