Agricultural production in China occurs via three distinct organizational units: the countryside farmer, state farms, and military farms. The countryside farmer in northeast China carries out most production operations with hand tools, some animal and tractor power, and little additional mechanization. Most weeds in row crops are controlled by hand, although a high percentage of the rice crop is treated with herbicides as is about 20% of the wheat. Countryside farmers independently manage small plots of land. State and military farms, the majority of which are located in China's northeastern-most province of Heilongjiang, are highly mechanized and accomplish most weed control with herbicides. Military farms range from ~500–2,500 ha, and state farms generally occupy 50,000–100,000 ha, with some much larger. Primary crops on the military farms are soybeans, oilseed rape, and wheat. State farms generally have more diversity in crops. The need for herbicide adjuvants to increase postemergence (POST) herbicide efficacy and for reduced tillage practices to combat soil erosion are recognized concerns, as is the threat of herbicide resistance.