The different viewpoint of Fertilizer Usage for Rice Production

Abstract

Rice seed contains 1.1% N, 0.20% P and 0.29 K. Rice straw contains 0.65% N, 0.10% P and 1.4% K. Traditional rice variety yields comparatively low 160-320 kg/rai. Natural supply of N are microorganism activities, rain water, river silt and decomposition of orranic matter. P enhances tillering and development of roots. Natural supply of K are from the weathering of soil parent materials and irrigation water. Potassium involves starch and sugar translocation, enhances amount of chlorophyll. The expected yield of 800-1,200 kg/rai need 12.8-24.0 kg N/rai and 8.0-10.0 kg K/rai. Recommendation of fertilizer application in sandy soil (16-16-8 + 46-0-0) may be worng since the amount of K may be lower than it is needed. Recommendation of application time as basal may also be worng because rice need K mostly for starch and sugar translocation to seeds.