Ratoon rice technology: A green and resource-efficient way for rice production

Ratoon rice, which refers to the production of a second rice crop from the stubble after the harvest of the main crop, is considered a green and resource-efficient rice production system. This review was undertaken to comprehensively evaluate the performance of ratoon rice in comparison with other rice cropping systems regarding the grain yield, grain quality, economics, and sustainability. In addition, the morphology and physiological bases associated with the performance of ratoon rice was also reviewed. With good crop management, ratoon rice gives a yield equivalent to 60% that of the main crop but with a 50% reduction in resources and labor input. Moreover, rice ratooning improves the grain quality, increases the profits for farmers, and decreases greenhouse gas emissions. Several agronomic practices for tiller-bud regeneration, such as nutrient and water management at the harvest of the main crop, establishment of the main crop, stubble cutting height and the variety selection and integrated technologies for the control of diseases and insects, were suggested to strongly affect the performance of ratoon rice. However, constraints, including low and unstable yield of ratoon crop, lodging, and lack of suitable cultivars and specialized rice harvester for the ratoon rice system, have limited the wide scale adoption of ratoon rice. Meanwhile, the mechanisms underlying the specific management strategies for ratoon rice need to be deeply studied.