Effect of sheep manure and Phosphorus fertilizer on potato and succeeding maize and cassava crops.

Abstract

A trial was conducted at the Menifo Sheep Research Centre located in the Eastern Highlands to examine the responses of potato, maize and cassava to application of sheep manure and inorganic phosphorus(P). Potato, maize and cassava were grown sequentially after the application of sheep manure and P fertiliser. Potato tuber yield increased with increasing rates of sheep manure. When manure was applied either at 10 or 20 t ha1, inorganic P significantly (P< 0.05) increased tuber yield but had no effect when either 0 or 40 t ha1 of manure was applied. At the same level of manure application, yield response to band application was significantly (P< 0.05) higher. Inorganic P failed to influence tuber yield significantly (P< 0,05) when manure was applied in bands. Residual effect of manure was observed in both maize and cassava Manure significantly (P< 0.05) increased the number and size of the marketable ears of maize , and the fresh tuber yield of cassava Residual P increased the number and size of marketable ears of maize significantly (P< 0.05) at 10 t ha1 of manure application only, and had no effect on cassava yield.