| The situation of water resource is the major factors affecting the regional food security, ecology security and economy security in the Huang-huai-hai Plain. At present, winter wheat-summer maize rotation system occupies a huge area in the Huang-huai-hai Plain. Most of the research focuses on the substitution of the current cropping pattern and the method of substitution. In this paper, the evaluation on the eco-cost of agricultural water consumption at County Luancheng is conducted through empirical study and macroscopic analysis. Field experiments on different cropping patterns are carried out based on the evaluation. The eco-function and economic returns of the cropping patterns are compared and analyzed comprehensively; afterwards, the cropping patterns under different possible conditions are optimized. The main results are as follows:1. The development of agriculture in this region cost huge water resource. The eco-cost of the over-consumption on water resource is about RMB 79,876,000 each year in County Luancheng, which is equal to 7.3% of the gross output value in crop production in 2000. The economic returns of food crop, economic crop and feed crop are reduced as much as 29.4%. Considering the eco-cost of water over-consumption, the current cropping pattern in this region is not sustainable.2. The eco-function and the economic returns could be strengthened by applying water-saving irrigation strategy to the current cropping pattern. When the irrigation amount was reduced for winter wheat (from 300 mm to 225 mm) and summer maize (from 180 mm to 120 mm), the water use efficiency and economic returns were increased as much as 23.0% and 47.6% for winter wheat - summer maize, respectively.3. With sufficient irrigation before sowing and 75 mm of irrigation during spring, applying water-saving and drought resistant type of winter wheat to substitute traditional winter wheat-summer maize system could improve 5.7% of the grain yield, 9.3% of the economic returns and 4.1% of water use efficiency, respectively. This demonstrates that the substitution of traditional high water-consumption wheat to water-saving and drought resistance wheat is a highly efficient strategy in water-shortage region, where the irrigation is insufficient for the eco-water consumption of wheat.4. The cropping pattern of spring maize monoculture has good ecological and economic effects in this region. The grain yield could reach 10268.4 kg/hm2 with irrigation amount of 180 mm, and the water use efficiency increased 122.6% than that of traditional cropping pattern and saved 62.5% of irrigation water. The economic return is also increased 36.6%. All these above show that the spring maize pattern is possible to become a high efficient water-saving pattern under water-scarcity condition, when the market-price of grain is fully open and the water resource is charged.5. The priority turns of cropping patterns according to their comprehensive benefits are: drought-resistant wheat-summer maize (no irrigation)>spring cotton>spring sweet potato>spring soybean> drought-resistant wheat/summer maize (irrigation of 135 mm)>spring peanut>feed maize> alfalfa>spring maize>wintergrazer rye-spring cotton>winter wheat-summer peanut>winter wheat-summer maize (irrigation of 270mm)>winter wheat-summer soybean>winter wheat-summer maize (irrigation of 345mm).6. To ensure the balance of water resource for this reason, the wheat planting area is the key problem. The results from stimulation show that the target yield has a negative correlation to economic return, and a positive correlation to eco-cost. The capacity of water resource for winter wheat production in this region is 10,790,000 ton, while the current yield is far more than 12,580,000 tons; if the aim is just satisfying the regional grain ration demand, the planting area could be reduced 11.4%, grain yield may be 38.8% lower than current pattern, but the economic return may increase 36% due to the substitution of other high efficient crops; the planting area of wheat could reduce 16%; when satisf...
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