Electrical Resistivity Based Empirical Model for Predicting Cassava Plant (TMS 98/0505) Tuber Yield on Sandy-loam Soil

This study examined the effectiveness of soil electrical resistivity (ER) as a tool for tuber yield prediction. Electrical Resistivity survey was conducted on sandy-loam soil from the soil surface at 0 0.3 m (ER30) and 0 0.9 m (ER90) depths using multi-electrode Wenner array and Miller 400D resistance meter. After ER survey, Cassava plants stem cuttings each 0.25 m long were planted on the soil using standard methods. Twelve 12 months after, tuber yield parameters number of cassava tuber (NT), average tuber length (TL) and tuber weight (TW) were measured on cassava plants whose soil ER has been measured. The results indicated that ER correlates insignificantly with NT (r = - 0.05) and TL (r = 0.04). ER90 also correlates insignificantly with TW (r = - 0.03) while ER30 correlates significantly with TW (r = - 0.84). Lower ER30 areas exhibited higher yield than higher ER30 areas. Soil ER30 between 250 and 500 m supports TW better than ER30 greater than 500 m. The relationship between ER30 and TW was best fitted to Lorentz (R2 = 0.85), Gauss (R2 = 0.84) and Boltzmann (R2 = 0.82) distributions.