Maize Yields Response to Application of Organic and Inorganic Input Under on-Station and on-Farm Experiments in Central Kenya

SUMMARY This study investigated the feasibility of using sole organics or a combination of organics with inorganic fertilizer to improve maize production in on-station and on-farm experiments in central Kenya. In the on-station experiment, combined application of Calliandra calothyrsus , Leucaena trichandra and Tithonia diversifolia at 30 kg N ha −1 plus inorganic fertilizer (30 kg N ha −1 ) consistently gave significantly higher maize grain yields than the recommended rate of inorganic fertilizer (60 kg N ha −1 ). Sole application of calliandra, leucaena and tithonia also increased maize yields more than the recommended rate of inorganic fertilizer. In the on-farm experiment, calliandra, leucaena, tithonia and cattle manure either alone or combined with inorganic fertilizer increased maize yields with a similar magnitude to that of inorganic fertilizer. These organic resources could therefore be used to supplement inorganic fertilizer as a whole or in part. There was a yield gap between on-station and on-farm trials with on-station yields having, on average, 65% greater yields than the on-farm yields. There is therefore potential for increasing yields at the farm level by closing the yield gap.