Abstract
Field trials were conducted to examine the growth and yield characteristics of rice (Oryza sativa L.) cultivated in deep-flood irrigation under no-tillage cultivation with single basal fertilization to the nursery box in hilly and mountainous regions, where low temperatures often cause cool weather damage and where labor-saving and low-cost cultivation is also required. Three water management regimes were designed: DF-I (deep-flood irrigation from early growth stage to heading), DF-II (deep-flood irrigation from productive tiller stage to heading), and CWM (conventional water management). The maximum tiller number and panicle number per m2 in the DF-I plot were smaller than those in the CWM and DF-II plots in 1999. In contrast, panicle number per m2 in the DF-II plot was comparable to those in the CWM plot in both years. Panicle number per m2 positively and significantly correlated with grain yield in 2000. The percentage of grain filling was significantly improved by DF. No significant differences in rice yields were observed among the water management regimes in both years. Nitrogen recovery of the fertilizer by rice was not significantly affected by the water management regime, whereas the no-tillage plot showed higher nitrogen recoveries of the fertilizer than those of the tillage plot. Considering the results, we suggest that DW-II with no-tillage cultivation is effective for both avoiding cool weather damage and for developing low-cost and labor-saving rice culture in hilly and mountainous regions.
