Effects of Biogas Fertilizer and Seed Rates of Khao Dok Mali 105 Rice Variety in Nahwan Nam Tom

Abstract

A field experiment was conducted to investigate the effects of biogas fertilizer (pig sludge from biogas digester) and seed rates of Khao Dok Mali 105, an aromatic rice variety, in Nahwan Nam Tom, at Mae Hia Agricultural Research Station and Training Center, Chiang Mai University during rainy season 1997. The result showed that increasing seed rates significantly decreased in number of plant/m² (at harvesting time), shoot dry matter, leaf area index, height and yield.Seed rate at 6 kg./rai increased in number of spikelet/panicle than that of 12,18 kg/rai, but decreased in number of panicle/m²and empty seed. Seed rates of 6,12 kg/rai gave the same yield, but significantly higher than that of 18 kg/rai. While all rates of biogas fertilizer significantly increased in growth and yield production as compared to the control, except number of plant/m² (at 3 weeks after planting), empty seed and height. Seed weight (1,000 seed) was not affected by different seed and biogas fertilizer rates. The interaction effect was on only shoot dry matter.Seed rates at 6,12 kg/rai gave the same yield, but the treatment of seed rate at 6 kg/rai and biogas fertilizer at the rate of 1,400 kg./rai produced grain yield about 421.8 kg/rai that was not significantly different from recommended chemical fertilizer that gave the highest yield.