The Effects of Tillage, Cropping and Fertilization on Extractable Soil Nutrients in Four Agro-Ecosystems in Ghana, West Africa

Abstract

Two experiments were conducted in four agro-ecosystems of Ghana: the coastal savannah, forest, forest-guinea savannah transition and guinea savannah. Experiment one assessed the effect of three tillage and four cropping treatments while experiment two quantified the effect of three triple super phosphate applications and six urea or compost applications. Two years after treatments commenced, soils were collected from a depth of 15 cm, air dried and sieved to 2 mm prior to acid extraction and analyses of Extractable Organic Carbon, Total Extractable N, NH_(4)-N-N, NO_(3)-N, Ca^(2+), Mg^(2+), Na^(2+) and K^(+). Although no strong and significant predictive models could be created for experiment one, in experiment two a promising predictive model could be created for K^(+) using agro-ecosystem and N application. Further findings indicate that agro-ecosystem had the largest effect on soil nutrient concentrations while the application of soil amendments will enhance extractable soil nutrients.