High efficiency and sustainable development models in Shanxi dryland agriculture regions

Dryland agriculture plays an important role in developing Shanxi local economy. Base on resource characteristics of dryland regions, three kinds of sustainable development models in Shanxi dryland agriculture regions are established. (i) the good cycling model of combining farming with raising an imals: its land productivity is increased by 49.7% compared with sole maize production system, a lamb gross weight increased by 11.3kg after 115 days, 14.1% more than that under traditional management. Grass output of slope is 12000～14400kg/hm².(ii) Model of sweet potato-processing-raising animals: its sweet potato yield is more than 75000kg/hm²，cost of starch film is lower 27.9% than PVC film, two kinds of sweet potato products are produced, the value of producing starch noodle is 10 times sweet potato. (iii) Eco-orchard model with double-way controlling soil water: compared with the clearing orchard, soil water content of 0～60cm depth in eco-orchard is more 3.1%, organic matter content of 0～40cm soil depth is 1.7g/kg higher, exchangeable potassium is more than 0.091mg/g soil. Four years after, the soil density decreases by 0.20g/cm³, number of pests enemy is more than 3 times, pests decrease by 95%, fruit diseases decrease by 80%, first grade fruit yield is 27000kg/hm², net income increases by 1338 yuan/hm².