Recent soybean subsidy policy did not revitalize but stabilize the soybean planting areas in Northeast China

With over 80 % of soybean demand dependent on imports, China has implemented multiple soybean stimulation policies to improve its soybean self-sufficiency. Northeast (NE) China, the leading soybean-producing region in China, produces more than half of the soybean in the country, and it is unclear whether agricultural policies had substantial effects on soybean planting areas and cropping patterns in NE China. Here, we generated annual crop maps at 10-m resolution in NE China during 2017–2021, and found that recent soybean producer subsidy policy released in 2017 has not revitalized but only stabilized the soybean planting areas in NE China, with a decline (−27.9 %) during 2020–2021 due to the high comparative benefits of maize cultivation. We found that a routine maize-soybean rotation system that might dominate the cropping patterns instead of the soybean subsidy policy. The effects of the routine rotation were more prevelant in the 2300–2700 ℃ d of the ≥ 10 ℃ accumulated temperature in NE China. The lower net profits of soybean than maize cultivation could be the major reason for the stagnant soybean planting areas, which could be attributed to the low yield of soybean and could not turn the tide only rely on limited producer subsidies. The soybean producer subsidy led to a stabilization of soybean planting areas, which could pave the way for future growth, and further actions are needed to stimulate soybean production in NE China, for example, maize-soybean rotation and maize-soybean strip intercropping which could achieve both productivity and sustainability.