Abstract: Xianyou is a famous high yielding region of sugarcane in Fujian.This paper deals with theoptimum structure of this field ecosystem in considering of natural and social resources,cropyields,and crop rotation.The balance of soil fertility and economic effects are analyzed bymathematical statistics and linear programming.Results show that optimum structure of fieldecosystem will give a net yield value of 11.18% and net returns of 11.74%.Both are higherthan the old management way.

Key words: Wheat, Leaf emergence, Dynamic model