Effect of Rice Straw Addition on Rice Production in Terraced Paddy Field Systems Sukristiyonubowo and Enggis Tuherkih

Studies on the effect of rice straw addition on rice production in terraced paddy field systems was carried out during the Wet Season of 2003-04 and Dry Season 2004 at Keji Village, Semarang District. Four treatments, including Improved Technology + Rice Straw (IT+RS), Improved Technology (IT), Conventional Farmer Practices + Rice Straw (CFP+RS), and Conventional Farmer Practice (CFP) were evaluated. Treatments arranged in a randomized complete block design, replicated three times. The objectives were (1) to assess the application of rice straw on rice yield, and (2) to evaluate seasonal variation of biomass production and grain yield. Biomass production for the Improved Technology + Rice Straw treatments was significantly higher than those of other treatments, both in the wet season 2003-04 and dry season 2004. Rice grain yields were 5.73 t/ha in the wet season of 2003-04 and 5.91 t/ha in the dry season of 2004. Significant improvement of rice grain yield was due to the increases of 1000 grains weight, the number of grains/panicle, and the number of filled grains/panicle. Significant increase of rice straw yield was due to the increase of shoot weights and for rice residue due to root weights. Seasonal variations were observed for grain and straw yields when rice straw was applied, similarly variations for the 1,000 grains weight, the number of grains/panicle, the number of filled grains/panicle and shoot weights, were observed. Rice straw is suggested to be incorporated into the soil during the land preparation, to improve soil quality.