Effect of Rice Variety and Nutrient Management on Rice Productivity in Organic Rice System.

Demand for organic rice has been increasing for decades. However, the information on sustainable organic rice production is still lacking. The objective of this paper was to investigate the effects of soil amendment, nitrogen rate, and variety on rice grain yield, yield component, grain protein, and chlorophyll content. Two paddy field experiments with four replications were conducted including rice variety (Presidio and Tesanai 2), soil amendment (Nature Safe and Rhizogen), and nitrogen rate (0 and 150 kg N/ha) in 2012 and 2013 at Beaumont, TX. Our data revealed obvious interacting effect of soil amendments, year, rice variety and nitrogen rate on panicle count. For example, under either Nature Safe or Rhizogen treatment in 2013, panicle count was two times higher than other treatments. Moreover, Presidio rice had significantly greater total grain milling yield and whole grain milling yield than Tesanai 2 rice under both nitrogen rate treatments and soil amendments. Besides, rice yield was higher at nitrogen rate of 150 kg N/ha (9,210 kg/ha) compared to 0 kg N/ha (8,176 kg/ha). However, no significant difference in rice yield and yield components was observed between two soil amendments. Furthermore, the data also showed that Tesanai 2 rice had greater rice yield and plant height than those Presidio rice. Our study indicated that variety selection and nitrogen fertilization of soil amendment can be an effective practice for high-yielding organic rice production.