Impacts of land-use types on soil physical quality: A case study of the National Centre for Genetic Resources and Biotechnology (NACGRAB), Nigeria

Abstract

Evaluation of soil quality (SQ) for land-use type impact is important for agricultural sustainability. This study was therefore conducted to quantify the impacts of land-use types (LUTs) on SQ under four LUTs (grassland, paddock, Irvingia wombulu plantation and Irvingia gabonensis plantation) at the National Centre for Genetic Resources and Biotechnology (NACGRAB), Ibadan, Nigeria. Soil samples were collected from each LUT and analysed for their physical, chemical and biological indicators. Effective indicators (air capacity, relative field capacity, soil structural stability index, clay, pH and organic matter) were selected as minimum data set (MDS) by principal component analysis. The Multiple Variable Indicator Transform (MVIT) and Sustainability Index (SI) techniques were used to transform and integrate selected indicators into SQ and soil sustainability indices. Soil quality was highest in grassland (72.3%), but decreased in I. wombulu, paddock and I. gabonensis by 15.2, 23.0 and 23.5% respectively, when compared with grassland. Soil sustainability under Grassland and I. wombulu was superior to paddock and I. gabonensis by 67%. Soil sustainability was significantly (R2 = 0.75, p < 0.01) linearly related to SQ under the four LUTs, indicating that SQ is a key to sustainable agriculture. Although, the four identified LUTs will require additional inputs (crop residue, manure, leguminous crops, etc.) to be agriculturally sustainable, grassland option is better for soil conservation.