Progress and challenges of rice ratooning technology in Chongqing Municipality, China

Abstract

Ratoon rice, the production of second crop from the dormant buds on the stubble after harvesting of the main crop, is considered an economic, environment-sound, and resource-efficient cropping system. This paper summarized the research progress of ratoon rice in Chongqing Municipality, the upper reaches of the Yangtze River, China in the past 30 years, and analyzed the physiological mechanisms behind the rice varieties with strong ratooning ability and the key practices for achieving high yield of ratoon rice. Ratooning ability and grain yield of the ratoon crop are highly and positively correlated with the initiation and growth of axillary buds, which can be promoted by optimizing variety selection, nutrient and water management, crop establishment method, stubble height, and harvesting method of the main crop. With implementation of those key practices, the grain yield could reach as high as 7.2 ​t ​ha⁻¹ of the ratoon crop with the main crop harvested manually. Due to the shortage of rural labor, mechanical harvesting of the main crop becomes an inevitable option for the sustainable development of ratoon rice. In the future studies, there is need to develop specialized harvesting machines and crop management strategies for reducing the rolling damage to stubbles during mechanical harvesting of the main crop, and consequently achieving high and stable yield of mechanized ratoon rice.