On April 19th, a field observation event for short-growing period canola varieties in the "rice-rice-oil" cropping system was held in Suichuan County, Ji'an City, Jiangxi Province. According to on-site yield measurements, the yield of canola increased by 50.95% compared to the locally promoted canola varieties, with a growing period of about 170 days. This achievement sets a new record for actual production per hectare of canola under the "rice-rice-oil" triple cropping system. It provides a replicable and promotable comprehensive technical solution for expanding canola acreage in the Yangtze River Basin and southern winter idle fields, ensuring the supply security of edible oil.
The "Mid-oil Early 1" oilseed rape variety, with a short growth period and high yield, has been successfully cultivated in contiguous plots of 100 mu in Tangjing Village, Yutian Town, Suichuan County. After field evaluations organized by the Oil Crops Professional Committee of the Chinese Crop Science Society, the segmented mechanical actual yield reached 166.05 kilograms per mu, with an oil yield of about 73.33 kilograms per mu (calculated at 44.16% oil content).
Currently, China's dependence on imported edible vegetable oil is as high as 70%, with imports mainly concentrated from a few sources, posing significant risks to supply security. Leveraging the abundant light and temperature resources in the Yangtze River Basin and the double-cropping rice areas in the south, planting short-growth-period oilseed rape during the winter fallow period of rice paddies (sowing after October 20th and harvesting before April 25th of the following year) and developing rice-oil multi-harvest production are crucial approaches to ensure food and oil supply while maintaining a foundation of grain production.
Supported by the national rapeseed industry technology system and the China Agricultural Academy of Sciences innovation project, the Oil Crops Research Institute of the China Agricultural Academy of Sciences has conducted technical research tailored to the rice-oil multi-harvest areas. Under the leadership of Professor Wang Hanzhong, an academician of the Chinese Academy of Engineering, the team successfully bred the "Mid-oil Early 1" oilseed rape variety, which boasts excellent yield and resistance. This variety overcomes the contradiction between high yield and short growth period, exhibiting strong seedling growth, late flowering, robust growth after winter, resistance to lodging and diseases, uniform maturity, and suitability for mechanical harvesting. In areas where rice-oil multi-harvest is practiced, planting densities can reach 35,000 to 50,000 plants per mu, and supporting high-yield planting technologies can further increase productivity.
From 2023 to 2024, the demonstration area of "Mid-oil Early 1" in major rapeseed-producing provinces such as Jiangxi, Hunan, Guangxi, Hubei, and Zhejiang in the Yangtze River Basin and southern regions exceeded 5,000 mu. Demonstrations at each site smoothly transitioned from the "rice-rice (again)-oil" cropping pattern, with shorter growth periods observed further south; in Beihai, Guangxi, the growth period is only about 130 days.
Experts suggest that the winter fallow fields in the Yangtze River Basin and the south hold great potential for expanding rapeseed cultivation using the multi-harvest model. However, the lack of high-yield, high-quality, short-growth-period rapeseed varieties has been a technical bottleneck hindering the comprehensive promotion of the "rice-rice (again)-oil" triple-cropping model in these regions. The large-scale success of high-yield, high-oil, short-growth-period rapeseed varieties represented by "Mid-oil Early 1" demonstrates a new productive force enabling efficient year-round production in the "rice-rice (again)-oil" model, thus promoting high-quality agricultural development.
