Growth and Yield of Organic Rice as Affected by Rice Straw and Organic Fertilizer

Abstract

The objectives of this research were to investigate the effect of rice straw management and the application of different types of organic fertilizer on the growth and yield of transplanted rice grown under rainfed conditions. The experiment was conducted in a farmer's field in Khon Kaen province in 2009. A Randomized Complete Block Design was used with four replications. The treatments consisted of (1) rice straw incorporation into the soil, (2) rice straw combined with cattle manure, (3) rice straw combined with bio-extracted fertilizer and (4) rice straw combined with cattle manure and bio-extracted fertilizer. In the present experiment, the rice straw remaining in the paddy field was incorporated into soil after the rice harvest in April. Then the rice was transplanted in August. The amount of rice straw and cattle manure incorporated into the soil were about 5.1 and 9.4 tons/ha respectively, which provided N 129 kg/ha, P 41 kg/ha and K 382 kg/ha. A liquid bio-extracted fertilizer was applied into the soil during the incorporation of rice straw at a rate of 30 liters per hectare which provided N 28 g/ha, P 5 g/ha and K 135 g/ha and foliar application at 60 days after rice transplanting which provided N 1.11 g/ha, P 0.18 g/ha and K 5.4 g/ha. It was found that the application of different types of organic fertilizer combined with rice straw had a significant effect on plant height, but did not show any significant effect on leaf area and aboveground dry weight at 30 days after transplanting and at panicle initiation growth stage. At harvest, total aboveground dry weight and panicle number were significantly affected by the application of different types of organic fertilizer. The treatment of rice straw combined with cattle manure and bio-extract fertilizer gave the maximum panicle number. The treatment of rice straw combined with cattle manure gave maximum grain yield, but did not show any significant difference from the treatment of rice straw combined with cattle manure and bio-extracted fertilizer.