Study On Facilitation Mode And Its Mechanism Of Maize Intercropped With Peanut

The monoculture practice in modern agriculture,which is characterized by hight-imput,has played an important role in relieving food crisis to some extent.But it also leads to the decrease of farmland ecological carring capacity.People begin to introspect agrocultural behavior to explore agricultural pattern for sustainable development.The intercropping of maize and peanut has attracted a wide public concern due to the fact that it is a sustainable way to ensure the high productivity and stability of the cropping system with high-efficient utilization of agricultural resources.The previous studies on maize and peanut intercropping mainly focused on the competition and compensation of light resource,and the changes of N,P and Fe contents in soil under the intercropping regimes.It is still lack of deeply understanding of the ecological niche function exhibiting in interspecies interaction under the intercropping regimes.Therefore,it needs to further uncover the mechanism of the interspecific facilitation and its mode action in the intercropping system of maize/peanut.Accordingly,a field experiment was conducted in the test base of Dayang township,Putian city,Fujian province to investigate the yield performance and its mechanism on the interspecific facilitation between maize and peanut plants based on the principle of ecological niche.Firstly,maize and peanut were cultivated in four intercropping patterns(3:6,3:8,3:10 and 3:12);Then the best and worst intercropping patterns were determinded based on the tests;finaly,a field experiment of the two selected intercropping patterns was carried out under three different root separation treatments with no barrier(NB),mesh barrier(MB)and plastic film barrier(PB).Our results showed that:(1)Comprehensive analysis of land equivalent ratio,actual yield loss,system productivity index,resource utilization efficiency,the interspecific competitive competitive effect and the interspecific competitive rate,and in the four intercropping paterns,the results showed that monoculture has lower crop productivity in some degree compared with their monoculture,and the best intercropping pattern in maize/peanut ratio was 3:8,the worst was 3:12.(2)The advantage in crop production under intercropping regimes was trade off in PB treatment,suggesting that underground rhizosphere interaction facilitation between the two intercropped plants plays an important role in population yield of intercropping system.(3)The facilitation in the underground parts was decreased due to the expanding of peanut populations.(4)Underground part interactions to improve soil habitat is more suitable for crop growth in intercropping system than that in monoculture,therefore,it is suggested that soil habitat improvement can be regarded as the embodiment of the interspecific facilitation in the intercropping system.(5)The interspecific facilitation is much more conducive to the growth of peanut roots.(6)The trophic niche overlap was significantly increased through the underlying mechanism of the higher complementarity of nutritional ecofactors and the lower similarity of them in maize and peanut plants under the intercropping regimes,But in the presence of underground part interactions,needs to retain complementary demand for nutritions,at the same time,it also needs to reduce the nutritional similarity,which often leads to negative effects on each other caused by the competition,therefore,their trophic niche breadth will be broaden,consequently reduces niche overlap.(7)The underground part interactions result in changed microbial structure and its diversity,as well as bacterial niche breadth.