Assessment of the physical health of tropical agricultural soils in Isialangwa North, Southeastern Nigeria

Knowledge of the health status of agricultural soils is key in soil management to maintain healthy soils. This study aimed at evaluating the physical health status of tropical agricultural soils in Isialangwa North area of Abia State in Southeastern Nigeria. Surface soil samples (0 – 20 cm) were collected randomly using a free survey approach from three communities namely: Isingwa, Ngwaukwu and Ntigha and subjected to routine analyses. The physical health statuses of the soils were determined using physical soil health indicators, analysed using ANOVA and correlation coefficient and ranked from 0 to 3 with soil health classes of healthy, sub-healthy, weak and degraded respectively. Results showed that; the soils of the area were degraded and ranked 3 on the basis of aggregate stability as the values ranged from 6.96%-8.79% for WSA > 0.25. For bulk density, total porosity and hydraulic conductivity, the soils were healthy and ranked 0 with figures of (1.18Mgm3-1.29Mgm3), (51.09%—55.62%) and (0.009 cm/s – 0.011 cm/s) respectively. For soil structure, the soils had fine granular structure and ranked 2 and were rated weak On the basis of stoniness and drainage, the soils were healthy. For top soil depth, the soils of Isingwa and Ngwaukwu were healthy and Ntigha was sub healthy. For water retention, the soils were degraded and ranked 3 as the values ranged from 7.3% to 8.1%, while the soil colour was rated as weak and put into class 2 as the soils ranged from brown to reddish in colour. Physical health attributes of soils also had significant relationships with other soil properties. Generally, the average ranking of all the physical health attributes of the soils in the study area were 1 respectively for Isialangwa, Ngwaukwu and Ntigha and so, the soils were rated as physically sub healthy based on the physical overall attributes. Therefore, it is recommended that good soil conservation practices alongside good management techniques will boost the physical health of the soils of the area.