Abstract:The study has been finished on shuang liu farm of the Institute of Biology Chengdu, Academla Sinica.The present paper deals with the ecosystem on Density-Planting patterns for 3×7 5×7 7×7 square cun in median rice. We Assume the system to be linear, and time-invariant, and the same conditions in fertilizer and water. Therefore we get linear time-invariant ecosystem of feedback of single input and single output. The general formula of transfer function and, of each main loop is obtained by systematic block d...