Decomposition of Vetiver Shoot and Effect of Vetiver Mulching on Super Sweet Corn Hybrid Yield

Abstract

Two experiments were conducted on Hupkapong Soil Series. In the first experiment, the decomposition of vetiver shoot, and the nutrients released during the process were measured. The second experiment investigated the mulching effect of vetiver shoot on yield of super sweet corn hybrid in the wet and dry seasons. The results from the decomposition study indicated that, within 90 days, more than 80% of the buried vetiver shoot decomposed but less than 30% of the same material left on soil surface disintegrated. It was also found that one ton of dry vetiver shoot buried at the depth of 10 cm would yield mineral nitrogen, available phosphorus, and extractable potassium up to 4.4, 2.2 and 20.5 kg while that left on soil surface would yield only 0.85, 0.74 and 7.20 kg, respectively. In the second experiment, the application of 31.25 t/ha fresh weight of vetiver shoot for mulching in addition to a half rate (35.5-35.5-35.5 kg of N-P₂O₅-K₂O/ha) of the recommended fertilization produced the same yield of super sweet corn hybrid as applying the full rate of the recommended fertilizer alone. Mulching the soil with vetiver shoot, therefore, could reduce 50% of chemical fertilizer needed for the super sweet corn hybrid production.