Comparative assessment of soil degradation potentials of commodity crops grown in Nigeria

Comparative assessment of land degradation potential of commodity crops grown in Jaba Local Government Areas of Kaduna State, Nigeria was investigated to provide evidence for crop-specific land management practices in the area. Soil samples collected from plots of four (maize, ginger, mango, and oil palm) main crops grown within three (Ungwan Rana; Kurmin Kwara, and Kyari) communities were analysed for relevant physico-chemical variables using standard laboratory procedures. The preliminary results of laboratory analyses showed that soils, where annual crops were grown had a higher content of sand particles, higher bulk density, pH_(water), mineralization (lower carbon content), and gravimetric water content when compared to soils where permanent crops were found growing. Soils, where tree crops were growing, had a higher silt, clay, and organic matter content. Results from the erodibility factor (k) estimation indicated that ginger production in Kurmin Kwara had the greatest impact of all three sites and crops investigated with an annual soil loss of 12 kg/ha/annum. Mango production in Ugwan Rana resulted in the least impact with an estimated loss of 9 kg/ha/annum of soil to erosion. Evidence of two-way analysis of variance of land degradation (erodibility) data at a 95% confidence level in SPSS version 21 indicated that the impacts resulting from the cultivation of different crops in various communities are not significantly different from one another. Therefore, soil conservation measures such as mulching, composting, land fallowing, and cover cropping would be helpful in eliminating the emerging land degradation owing to the cultivation of commodity crops in the study area.