Effect of tied ridges on grain yield response of maize (Zea mays L.) to application of crop residue and residual N and P on two soil types at Alemaya, Ethiopia

Field experiments were conducted on two soil types over a period of five years (1986–1990) to investigate the effects of tied ridges and planting systems on the grain yield response of maize to applications of crop residue and residual N and P fertilizers. Grain yields were increased by the use of tied ridges. Further increases in grain yields resulted from residual N and P and crop residue applied separately or together. Under all fertilization practices, planting in the furrow of tied ridges resulted in higher grain yields than planting on top of tied ridges. The effect of the tied ridges in increasing grain yields was generally better in the drier periods and the more so when the ends of the ridges were tied. In wetter seasons the open end tied ridges gave higher yields than the closed end tied ridges. The effect of tied ridges on grain yield response of maize to application of crop residue and residual N and P fertilizers was influenced by rainfall and by soil type.