Due to the scarcity of the water resources in Anhui Province,developing water saving irrigation is the fundamental measure,which can relieve the conflict between water supply and demand,realize the optimal allocation of the water resources,promote the adjustment of agricultural planting structure,and achieve sustainable development of agriculture.

Agriculture plants Structural adjustments a hot work.

The changes of nutrient balances driven by adjusting crop structure at county level during 25 years——A case study in Huimin County,Shandong Province;

Optimization of crop structure by applying systematic dynamics;

In this paper,five issues of 11 agricultural counties in Yan an area are studied,which include the total area change of farmland and seeding;the change of planting structure;the change of agricultural investment;the total and average output changes of grain and oil plants;the change of per farmer income per year.

The four planting structures of economic grain,grass economic grain,forestry economic grass,and specialized production were considered to be suited to local farmland through the analysis and experiment of planting production in Zhungar Southern Fan Zone.

Combined with the feed comsumption of livestocks, the linear programming model of cropping structure adjustment has been established.