Influence of potassium fertilizer on yield of plantain intercropped with cassava on an oxic paleustalf in southwestern Nigeria

There is very little literature on the influence of plantain - cassava intercropped on this soil type. Therefore, an experiment was conducted in 1993 and 1995 cropping seasons on the influence of potassium (K) fertilizer on the yield of the two crops on a soil classified as Oxic paleustalf (or Ferric Luvisol) in the rain forest agroecological zone of Nigeria. Four rates of K fertilizer ( 120, 240, 360, and 480 kg K ha(-1)) and control were evaluated on the yield and yield components of these two crops in sole and intercropping. The experimental design was a randomized complete block (RCBD) replicated four times. Results showed that the soil is acidic and the exchangeable cations contents were suboptimal when compared with the optimum required for a sustained cultivation of plantain. Furthermore, the plantain cassava intercropped yields responded significantly (p < 0.05) to fertilizer applied in terms of the yield and yield components of both crops in sole and intercropping. Highest bunch weight of plantain and tuber yield of cassava was recorded at 360 and 240 kg K ha(-1) (taking the mean of both years). Potassium fertilizer after this point resulted in lower yields of both crops when intercropped.