882. Enhancing Health-Boosting Properties of Black Rice via Optimal Phosphorus Management

Rice is the most important crop in Laos and serves as the nation's staple food. In the 1990s, Laos achieved self-sufficiency in rice production and subsequently adopted rice production expansion and export as a key component of its economic growth strategy. However, as a landlocked country with high transportation costs and surrounded by rice-exporting powerhouses such as China, Thailand, and Vietnam, Laos faces the challenge of establishing its rice in the global market by offering high-quality and distinctive products. Therefore, JIRCAS has focused on Lao black rice as a promising commodity with excellent market potential.
 
In China and Southeast Asia, the tradition of consuming black rice for its health-promoting properties has persisted, commanding premium prices in local markets. Black rice exhibits a high accumulation of antioxidants, such as anthocyanins, in its pericarp, contributing to a wide range of reported pharmacological benefits. This accumulation of antioxidants is a natural defense mechanism against various stresses in rice plants. In Laos, where agricultural infrastructure is less developed, rice crops often face stresses such as drought and nutrient deficiencies, conditions that paradoxically enhance the production of black rice with high antioxidant content. However, this comes at the cost of reduced yields.
 
In tropical soils, phosphorus deficiency is known to be a major limiting factor for rice productivity. While supplying large amounts of the missing phosphorus can improve black rice yield, it's expected to compromise rice health functionality. Therefore, we investigated the effects of both high and low soil phosphorus levels on black rice productivity and functionality and published our results in Frontiers in Sustainable Food Systems in 2023 in a paper titled "Optimizing phosphorus management to increase grain yield and nutritional quality while reducing phytic acid concentration in black rice (Oryza sativa L.)". We have shown that even in phosphorus-poor soils, optimizing phosphorus fertilization can produce black rice with both high productivity and commendable health functionality. These research results indicate that balancing productivity and functionality through soil-specific phosphorus fertilization management is a critical breakthrough, particularly beneficial to the livelihoods of black rice producers in developing countries.

Reference
Aung Zaw Oo et al. (2023) Optimizing phosphorus management to increase grain yield and nutritional quality while reducing phytic acid concentration in black rice (Oryza sativa L).  Front. Sustain. Food Syst. 7:1200453. https://doi.org/10.3389/fsufs.2023.1200453

Contributors：ASAI Hidetoshi and Aung Zaw Oo (Crop, Livestock and Environment Division)