Fertility Status of Soils Under Silvopastoral System on Two Soil Types in Imo State, Southeastern Nigeria

Understanding the fertility status of soils under different agricultural systems is imperative for sustainable crop production and ecological sustainability. This study examined the fertility levels of soils under silvopastoral system of two soil types in Southeastern Nigeria. Two towns in two states with two parent materials in the region were covered namely Owerri in Imo State with coastal plain sand and Uturu in Abia State with false bedded sand stone. Surface soil samples collected within 30 cm depth were analyzed using standard methods. Silvopastoral system and parent materials guided the sampling points. Data obtained from analyzed soil samples were statistically analyzed. Significant variations existed in the particle distribution of the soil while highest gravimetric moisture content (249.7 g/kg), total porosity (67.5%) and lowest soil bulk density (0.85 g/cm3 ) were recorded in the silvopastoral lands than in non silvopastoral lands. Silvopastoral lands contained higher soil organic matter (36. 88 g/kg), total nitrogen (1.87 g/kg) and exchangeable bases than non silvopastoral lands. There was higher clay content (274 g/kg) in false bedded sandstone than in coastal plain sand silvopastoral lands. The highest value of soil organic matter (36.88 g/kg) and total nitrogen (8.7 g/kg) were recorded in false bedded sandstone under silvopastoral system. There was significant negative correlation between bulk density and base saturation (r = -0.946) and positive relationship between total exchangeable acidity and soil bulk density (r = 0.865). This work revealed that parent materials under silvopastoral systems differ in soil physical, chemical and plant nutrient concentration. Therefore it is recommended that silvopastoral system should be adopted under coastal plain sand for soil fertility improvement due to its poor soil quality.