Soil productivity improvement under different fallow types on Alfisol of a derived savanna ecology of Nigeria.

Fallowing is considered an important management strategy for the restoration of soil productivity. Therefore, a three-year fallow of pigeon pea (), mexican sunflower () and elephant grass () was established at Landmark University, Nigeria between 2016 - 2019. Leaf nutrient concentrations of maize () planted with soils taken from each fallowed plots after three years were also determined. The experimental design was a randomized complete block design with three replications. Soil samples were collected from each fallow plots for physical and chemical analysis (bulk density, porosity, moisture content, particle size, dispersion ratio, soil erosion loss, soil organic matter (SOM), total N, available P, exchangeables K, Ca, Mg, CEC and pH.) before and at the end of the experiment. Means of data collected were separated using Tukey's HSD test at p = 0.05. fallow improved soil properties and leaf nutrient concentration of maize compared with and fallows. The order was > > . This was adduced to the regular return of plant residues to the soil in fallow which resulted in high SOM ( increased SOM by about 23%, 7.5%, and 20%, respectively, compared with the initial soil, and fallows) and increases soil N, P, K, Ca, Mg, CEC and pH and also stabilized soil structure by increasing porosity, moisture content and reducing bulk density, dispersion ratio, and soil loss. Therefore, plant species of high nutrient contents and high return of biomass to the soil are necessary for quick restoration of soil productivity in a derived savanna ecology.