| Abstract: | We investigated the effects of integrated organic and inorganic fertilizers on the growth and yield of indica rice variety Manawthukha and japonica rice variety Genkitsukushi. In a split-plot design, the two rice varieties were assigned as main plot factors, and the integrated treatments were the subplot factors, including no-N fertilizer(N_0), 50% chemical fertilizer(CF)(CF_(50)), 100% CF(CF100), 50% CF + 50% poultry manure(PM)(CF_(50)PM_(50)), 50% CF + 50% cow manure(CM)(CF_(50)CM_(50)), and 50% CF + 50% compost(CP)(CF_(50)CP_(50)). CF100 was equivalent to N at 85 kg/hm~2. Manure was applied based on the estimated mineralizable nitrogen(EMN) level, which is dependent on total N(%) of each manure type. Manawthukha rice plants were taller with higher tiller number and dry matter content. However, higher soil-plant analysis development(SPAD) values were measured in Genkitsukushi throughout the crop growth period, resulting in higher seed-setting rate(%) and greater yield. At the same N level, CF_(50)PM_(50) application in both rice varieties resulted in higher SPAD values, plant height and tiller number than CF_(100). CF_(50)PM_(50) containing total N more than 4% supplied synchronized N for the demands of the rice plants, resulting in maximum dry matter, yield and yield components. CF_(50)CM_(50) and CF_(50)CP_(50) treatments containing total N less than 4% resulted in lower yields which were similar to CF_(100). These results indicated that integrating organic and inorganic fertilizers enhanced growth parameters and yields of Manawthukha and Genkitsukushi, while reducing the dose of chemical fertilizer. |
