Evaluation of the efficacy of selected ameliorants to alleviate soil crusting, with a view to reclamation of degraded land, in Dinokeng Game Reserve

Abstract

Soil crusting is a serious problem throughout South Africa in crop farming, rangeland and wildlife reserves, leading to reduced water infiltration, increased runoff and ero-sion, inhibited soil aeration, germination and seedling emergence. Crusted soils of-ten do not recover after several decades as seen in Dinokeng Game Reserve (DGR) where the study was conducted. Selected ameliorants which are effective in the amelioration of soil crusts in cropping areas were assessed. These were PAM at two levels, Gypsum, Molasses meal and combinations thereof, and also brush packing. The methods used in testing the ef-ficacy of the ameliorants in the field study were crust strength and final infiltration rate. Structure stability tests were done by means of wet sieving. Seedling emergence of sown in grass was determined in the field. All amendments, except gypsum and gypsum + PAM, were statistically significantly effective in creating stable soil structure. PAM performed well in the field trial and pilot study. The high efficacy of the lowest PAM treatment is economically important.