Soil Nematode Community Structure Characteristics And The Relationship With Soil Food Web In Fruit/Grain Intercropping System In Sourthern Xinjiang

Furit/food crops intercropping system is one of the most widely applied agroforestry systems in Xinjiang, northwest China, due to its good ecological, social and economic benefits. Intercropping systems have many advantages, for example increasing the economic income, windbreak and sand-fixation, making effective use of resources, achieve fruit and crops complementary advantages and so on. But there is still unknown that long-term sustainability of the development. On the orther side, there is little knowledge of soil nematode changes in intercropping system which response to soil food web diversity and structure impacted by interaction of intercropping plants, and also lack of characteric describes of nematode community in southern Xinjiang. To evaluate the rationality and persistent of intercropping system, we selected jujube, apricot, walnut intercropped wheat and maize, respectively, as our research object, and analysed soil nematode community structure characteristics and the relationship with the soil food web.The main results list as below:There were the negative effects on wheat in furit/wheat intercropping system. Compared to wheat monoculture, soil moisture content was increased, the value of C/N was lower; soil nematode abundance was decreased; the relative abundance of Rhabditis and Diploscapter were lower, the relative abundance of Tylenchus was higher; the values of WI were lower; the values of EI were lower in walnut/wheat and apricot/wheat intercropping system, there tend to mainly fungi degradation pathway in apricot/wheat intercropping system; there was no significantly difference in diversity and structure of soil food webs.There were the positive effects on fruit trees in furit/wheat intercropping system. There was no significantly difference in soil physical and chemical properties; soil nematode abundance were increased in furit/wheat intercropping system, in addition to old walnut trees; the relative abundance of Rhabditis and Diploscapter were higher, the relative abundance of Tylenchus and Paratylenchus were lower in jujube/wheat intercropping system; the relative abundance of Acrobeloides was higher, Aphelenchus was lower in apricot/wheat intercropping system; the relative abundance of Rhabditis and Diploscapter were higher, the relative abundance of Acrobeloides and Aphelenchus were lower in young walnut/wheat intercropping system; there was obvious difference in the nemtode composition between superficial and deep layers of old walnut/wheat intercropping system. There tend to mainly bacterial degradation pathway in furit/wheat intercropping system; the value of WI was higher; in addition to the old walnut, all can affect the maturity index of soil food web.There were the advantages in apricot/maize intercropping system. The soil mositure content was increased in maize rhizosphere, and was no significantly differed in furit rhizosphere of furit/maize intercropping system. Compared to monoculture, nematode abundance were increased in intercropping system, mainly because the larger numbers of cp-2guild. It was benefit for maize that intercropping with apricot, it has no significantly effect for maize that intercropping with walnut, with no related with age. For furit trees, the relative abundance of Acrobeloides and Aphelenchus were higher; it was favourable for energy circulation in apricot rhizosphere soil food web that intercropped with maize; it has no significantly effect on old walnut and changed young walnut rhizosphere soil food web tend to fungi decomposition pathway.Mode (intercropping and monoculture) and plants could be well described by the distribution of soil nematodes, and more effected soil nematode distribution than soil physical and chemical properities. The decomposition channels of soil food web were effected by intercropping mode, while diversity of soil food web were no significantly effected. Over all, there were advantage for furit trees intercropped with food crops, advantage for maize intercropped with furit trees, and disadvantage for wheat. The soil mositure was increased in food crops soil rhizosphere that intercropping with furit trees.