Zhao Yixue, Li Hongjian, Wang Ming
According to the observed data of heat and Water in the basins in middle areas, Shanxi previce, the paper analyses the heat and water conditions there under different cropping system, by using the following formulas: K=H-(ΣA+G)+ΔA, K=2H-(ΣA+G)+ΔA and B=P+C+(W1-W2)-(R+I)-E It alse colculates the budget of heat and water (not having irrigable condition) to the main field crops respectively. It shows.As to one crop per annum, heat surplus in the fields of winter wheat (≥0℃ cumulative temperature, else crops are ≥10℃. cumulative temperature), corn and millet is about 222.3℃, 937.4℃ and 1187.1℃ respectively. Heat deficit in the field of cotton is about 142.9℃ heat surplus is about 860.7℃ only in Linfen and Yuncheng basins, water deficit in the fields of winter wheat, corn, cotton and millet is-about 96.4mm 121.9mm 53.6mm and 151.1mm respectively.As to two-year-three crop system, heat surplus in the fields of crops(planting corn, winter wheat and millet) is about 779.2℃ heat deficit inthe field of crops is about 302.7℃ in Xin-ding basins. Water deficit inthe field of crops (planting corn, winter wheat and millet) is about 388.5mm.As to two-crop a year, if planting winter wheat and corn, heat deficit is about 165.5℃ and water deficit is about 196.3 mm. If planting winter wheat and millet, heat surplus is about 84.4℃ and water deficit is about 291.9mm in Yuncheng basin.From April to May is a period of the highest water consumption of winter wheat and the sowing time of corn, cotton and millet and the time of heat in field is higher. But in this period precipitation is the lowest. Therefore, a complementary amount of water is required in irrigation.The analysis and computation of the heat and water budgets are to provide scientific basis for making full use of the thermal resources, economizing on water resources irrigating crops in field rationally, developing the economy of Shanxi province.
