Estimation of soil quality under different soil management practices in the Oxisols soil of Mauritius

Soil is considered as one of the most important environmental factors for plant growth. However, the challenge is quantifying the sustainability of soil in agro-ecological systems. Presently, no soil quality assessment has been carried out in the island Mauritius or Small Island Developing States (SIDS) which would help to provide more scientific and precise advice to farmers for fertilisation and/or amendment of the soil. This is a particular handicap when recommendations need to be formulated to shift from conventional agricultural practices to a more sustainable and ecosystem-based approach. The present study attempted to determine the limiting factors of soil quality characterisation following different treatments comprising of mulch, no-mulch, N-based fertiliser, no fertiliser, tillage and no-tillage, and thereafter compare the differences in soil quality with conventional practices. In the present study, soil organic carbon (SOC), bulk density (BD), exchangeable potassium (Ex. K), exchangeable calcium (Ex. Ca), exchangeable magnesium (Ex. Mg), available phosphorous (Av. P), total nitrogen (Total N) and pH were selected as part of the Total Dataset (TDS) and the weighted additive Soil Quality Index (SQIw) of each of the eight treatments was calculated and compared. The study revealed that the SQIs ranged between 0.269 and 0.387 among all treatments, which suggest a low soil quality irrespective of the treatment. On a comparative basis, treatments no-till x mulch x fertiliser, no-till x no-mulch x fertiliser, and tillage x mulch x no-fertiliser are three options that can replace the conventional method tillage x no-mulch x fertiliser (control) based on the SQI.