Preliminary Studies On Ecological Manipulation Technology Of Rice Production In Hejia Village, Samen County, Zhejiang Province

Ecologically-Based Pest management strategy is an inevitable trend in pest management development. Although development of green technology to prevent and control pests is widely proposed and discussed, there is few reports about this technology used in fermers' fields. Rice farmers in Hejia Village, Sanmen County, Zhejiang Province, have been using the ecological manipulation principles through the conservational natural biocontrol methods to effectively manage the insect pests without insecticide and fungicide during the whole rice growing season for 10 years. They also achieved significant economical, ecological and social benefits.From 2007 to 2009 we sampled the arthropod diversity in Hejia villiage paddy, especially herbivore and predator populations. We found that this village is rich in biodiversity. In such natural conditions, the populations of wolf spider and microspider assemblages pursued the temporal population dynamics of planthoppers and leaffolders in a significant way. Furthermore, the existence of progressive-type curves of spatial numerical responses of spiders to planthoppers during the early-mid season resulted in a lower density of planthopper populations in the mid-late season.From 2007 to 2009 through farmer survey on rice production efficiency in Hejia and other nearby villages, we found in the whole Sanmen county, the cost of rice production cost increased 18% every year and yearly pure income increase 3.5% only; on the contrary in Hejia village revenue reached RMB Yuan 1787 per mu in 2009, and pure income increased 27.6% yearly, due to no insecticide and fungicide application, which included RMB Yuan 102 of saving agricultural inputs, Yuan 146.5 of labor saving, Yuan 43 of higher price of rice grain and government subsidies.In Hejia village, the implementation of ecological manipulation approach was the results from local farmers'knowledge, attitude and practice about rice pests and their management. They have basic knowledge of science, ecological consciousness. They are also good at learning and self-improving. Because of farmland locating in mountain area, high cost of labor, most of farmers out-going, shortage of labor, native farmers have the practive of culturing rice paddy without pesticide and less fertilizer gradually. Our survey showed that farmers living in mountainous area are more like to accept and try conservational biocontrol techniques easier than the farmers living in plain area. So, more attention should be paid to the mountainous farmers to explore the anthropological mechanism underlying the ecological manipulation practices.