Soil Properties under different tillage methods in the cotton-growing area of northern Benin

Abstract

Objectives: The pattern of land use inevitably has an impact on soil quality. To assess the impact of tillage methods on the physicochemical and biological properties of soils, four tillage methods were tested in the cotton-growing area of northern Benin.

Methodology and results: These were manual tillage (Lm), conventional tillage (TC), surface tillage without soil turning (TMs) and deep tillage without soil turning (TMp). A Random Complete Blocks Design constituted of the four tillage methods and three replications was implemented on Bensékou, Kokey and Banigouré sites. The experiment was repeated over three years. The linear mixed-effects model was used to compare the effect of tillage patterns on physicochemical and biological parameters in 0 - 10 cm and 10 - 20 cm soil horizons. The results showed that all tillage methods decreased the water, carbon and nitrogen content, bulk density, available water content and macrofauna biomass (p ˂ 0.05) in 0 - 10 cm layer. In 10 - 20 cm horizon, only TC improved significantly the available water content and nitrogen content (p < 0.001).

Conclusions and applications of findings: From this study, TC beneficially impacts soil fertility better than TMp and TMs. Subject to a study on the impacts of these tillage methods on productivity of cotton plant, it is, therefore, recommended for three successive agricultural campaigns, conventional tillage in view of the good soil preparation for the cotton cultivation.