Abstract:Based on the joint experiments of corn agricultural ecology in 31 cities and counties in Heilongjiang province and on the model connection according to the theory of double combination design, a mathematic model of corn regional production in Heilongjiang is established. It reveals to what extent the accumulated temperature, precipitation, soil fertility, farm manure, and chemical fertilizers can affect corn yield. The model also reveals the regularity of variation of those factors. The model has already be...