Nitrogen and Potassium Status of Selected Soils and Their Effects on the Growth, Yield and Cyanide Content of Cassava (Manihot esculenta Crantz) in Delta State, Nigeria
This study was conducted to evaluate the nutrient status and the effects of Nitrogen and Potassium fertilizer on the growth, yield and Hydrogen cyanide content of cassava (Manihot esculenta (L) Crantz) in Delta State, Nigeria; Representative soil samples were obtained from Abraka, (Rainforest zone); at 0-15cm and 15 -30cm depths. These were analyzed for their physical and chemical properties. The design was a 4×4 factorial scheme fitted into a Randomized Complete Block design giving 16 treatment combinations with 3 replicates. The following treatment combinations of N and K were applied: N0K0(no fertilizer), N0K20,N0K40, N0K80, N40K0, N40K20 N40K40, N40K80,N80K0, N80K20,N80K40, N80K80,N120K0, N120K20,N120K40, and N120K80 kg/ha-1 The plant parameters measured were: plant height. These were taken at 2,4,6,8 and 10 months after planting (MAP). Fresh tuber weight and Hydrogen content of tuber were also determined. In the trials involving the application of N, K and their combinations, K had significant effect 2-10 MAP on plant height at (p<0.05) influenced fresh tuber weights of cassava. It was concluded that 120kgN/ha in combination with 20kgK/ha be applied to soils in the study area for the cultivation of cassava variety for best tuber yields and hydrogen cyanide content.