Assessment And Technical Countermeasures Of Ecological Safety Of Cropping System In Suburban Region In Beijing--A Case Study In Shunyi County

Considering the ecological problems of the cropping system of Beijing, we make a study on theecological safety of cropping system based on the case study in Shunyi On the basis of theevaluation, some key facts of the cropping system are analyzed and predictions are put forward forthe unsafe facts. The study provides the cropping system with technologies by summing up thewell-researched technologies and testing. Main results are generalized as follows:The index system has been built as the aspects of quality and quantity are considered.The quality of atmosphere subsystem is the best of the four departments. It can provide the goodenvironment for Shunyi's further development. Judging from the quality index, the watersubsystem, the soil subsystem, the crop subsystem are all good, but there is still something shouldbe alert on the quantity index of them.The general situation is good of the cropping system; however, most of the members are at theedge of the safety. We should keep watch on them in case their deterioration.With the use of soil, there is more heavy metal in it. At the same time, the water supply for crop isat the price of drawing the groundwater unduly. So we make a prediction for conditions of them.As crop system is so complex, we study the technologies of the optimum design of fertilizer, thedecomposition of DDT through compost. In the same time we summary some other technologies,such as rotation, conversation tillage, water-saving of structure. So we can provide the technicalcountermeasures for the ecological safety of Shunyi's cropping system with these keytechnologies.