Study On The Interspecific Effect Of Potato Intercropping With Maize

Intercropping is a kind of intensive use of resource,which can alleviate the occurrence of soil diseases caused by perennial continuous cropping,and plays an important role in improving soil environment and improving land use effeciency.In this experiment,potato intercropping maize was taken as the research object,and single factor random block design was used to analyze the interspecific effect of intercropping crops and the response of soil bacteria to different cultivation modes under the continuous positioning test from 2017 to 2018.The biomass and community structure of soil bacteria in intercropping cultivation were analyzed by molecular biological methods.1.The results show that:In 2018,the initial fluorescence(FO)value and Non-photochemical quenching coefficient(NPQ)value of intercropped potatoes were significantly higher than those of monocultured potatoes 87.24%and 49.38%,indicating that the fluorescence yield and heat dissipation capacity of the reaction center of the leaves of intercropped potatoes were higher than those of monocultured potatoes when the reaction center was fully open,and the maximum photochemistry quantum yield(Fv/Fm),photochemistry quenching coefficient,actual photochemistry quantum efficiency of PS ?and effective photochemistry quantum yield in intercropping maize were higher than those in monoculture.The net photosynthetic rate and stomatal conductance of maize intercropped were higher than those of maize monocultured for two consecutive years,and the difference was significant in 2017.And the transpiration rate of potato monocultured for 2018 was significantly higher than that of potato intercropped for 54.07%.2.The contents of total nitrogen and total phosphorus in stems,leaves and grains of Intercropped maize were higher than those of monoculture in two consecutive years.In 2017,the contents of total phosphorus in maize's grains of intercropped maize were significantly higher than that of monoculture in 0.14%.The contents of total nitrogen in intercropping maize's grains was significantly higher than monoculture maize by 17.12%,and total phosphorus in intercropping maize's leaves and stems were also significantly higher than that of monoculture maize by 88.89%in 2018.In the same year,the total nitrogen content of intercropping potato's tubers was significantly higher than that of potato monocultured by 16.83%,and the contents of total phosphorus and total potassium in intercropping potato's tubers and leaves and stems were also higher than those in monoculture potato.3.In two consecutive years,the above ground biomass of intercropping was higher than that of monoculture,and the biomass gap between intercropping potato and monoculture was greater than that of maize;In 2018,intercropping LER>1,showed that the intercropping advantage.The interspecific competitiveness of potato was greater than that of maize in two years.4.In 2018 year,the content in intercropping soil was 4.80%and 4.63%higher than that in monoculture maize and potato treatments of organic matter,which was significantly different from that in monoculture maize.And there was a signifieant positive correlation between soil organic matter and crop yield.The available phosphorus in intercropping cultivation was 4.25 mg.kg-1 higher than that in monoculture maize.In 2017,the available potassium in intercropping soil was 40 mg.kg-1 and 27 mg.kg-1 higher than that in monoculture of maize and potato.5.Compared with monoculture treatment,intercropping decreased the ratio of Gram-positive bacteria to Gram-negative bacteria in soil.T-RFLP results showed that Shannon index and Evenness index were increased in intercropping cultivation compared with the two monocultures,while Simpson index was the opposite.New dominant fragments with 148 bp length appeared in enzyme digestion fragments.The abundance of beneficial functional bacteria in soil was also higher than that in monoculture,on the contrary,the richness of potential pathogenic bacteria in intercropping was lower than that in single cropping.In addition,the relative abundance of four beneficial genera for Nirosomonas,Arthrobacter,Spirulina and Acetobacterium,which did not appear in single cropping.6.The results of high-throughput sequencing showed that intercropping did not increase the number of bacterial OTUs.monoculture maize,intercropping,and monoculture potato.The results of high-throughput sequencing showed that the correlation between soil nutrient content and bacterial under the phylum level was similar to that of T-RFLP.The abundance of Proteobacteria increased with the increase of available phosphorus,available potassium and available nitrogen content in soil,and abundance of Proteobacteria decreased with the increase of soil total nitrogen,total phosphoras,organic matter content and the numerical value of pH.Total nitrogen content was also positively correlated with the abundance of Thaumarchaeota.