Progress and challenges of rice ratooning technology in the south of Henan Province, China

Rice ratooning technology is on the rise in Henan Province of China, an area that has traditionally been considered unsuitable for ratoon rice due to limited thermal resources. In this review, we presented the current status of ratoon rice production in South Henan and reviewed the research progress on variety selection, high-yielding crop management practice, and innovative ratoon rice-based cropping system in this region. The key practices for high-yielding ratoon rice production include using short to medium duration rice varieties, early planting, early harvesting, and high cutting height. As a result of the introduction of these high-yielding practices, the harvested area of ratoon rice has increased to 40,000 ​ha annually in South Henan in recent years. Meanwhile, ratoon rice production in South Henan is facing several challenges and constraints, such as chilling injury at seedling stage, inappropriate N fertilizer management, and large yield losses in ratoon season due to rolling damage from mechanical harvesting of the main crop. Nonetheless, these issues could be addressed by placing particular emphasis on optimizing seedling-raising system, selecting rice varieties with high resistance to mechanical rolling, and fine-tuning crop management practices for mechanized rice ratooning. As such, we believe that this review will shed light on the development of ratoon rice in Henan and other regions with limited thermal resources.