Effect Of AMF Inoculants And Their Diversity On Yield,Nutrient Uptake And Soil N₂O Emission Of Maize

To determine the effects of Arbuscular Mycorrhizae fungal(AMF)inoculants their diversity on maize grain yield,nutrient uptake and soil nitrous oxide(N2O)emission.Two pot experiments were established during the maize growing period in 2019 and 2020 years.Experiment one was the different AMF inoculants and their diversity of species level.Four different AMF species(Funneliformis mosseae:A;Glomus tortuosum: B;Glomus versiforme: C;Funneliformis geosporum: D)were selected,which had sixteen treatments,including: CK(non-inoculating AMF),inoculating single AMF treatment,two AMF mixed treatments,three AMF mixed treatments and four AMF mixed treatments.Experiment two was the different AMF inoculants and their diversity of genus level.Three different AMF families(Funneliformis mosseae: A;Acaulospora scrobiculata: E;Gigaspora margarita: F)were selected,which had eight treatments,including: CK(non-inoculating AMF),inoculating single AMF treatment,two AMF mixed treatments and three AMF mixed treatmentsfour.The maize yield,biomass,AMF colonization,plant nutrient(N,phosphorus and potassium)content,soil NH4+-N,NO3--N content,N2 O emission were measured.The N2 O emission was determined by static box-gas chromatography.The effects of different AMF inoculants and their diversity on maize yield,nutrient uptake and N2 O emission was analyzed,to provide a theoretical basis for the application of farmland microbial fertilizer,improving crop nutrient uptake and agricultural sustainable development.The main research results were as follows: in the experiment of the different species level AMF inoculants and their diversity,compared with CK,all AMF treatments increased maize grain yield in the two experimental years,and the presence of A,B,C and D increased maize grain yield by 57.9%,26.9%,40.5% and32.9%,respectively.With AMF inoculant diversities increasing,the grain yield of maize increased,and the average grain yield of four AMF mixed treatment was 12.3%higher than single AMF treatments.In the different families level AMF inoculants and their diversity,compared with CK,all AMF treatments increased maize grain yield in the two experimental years,and the presence of A,E and F increased maize grain yield by 57.9%,29.7% and 23.7%,respectively.With AMF inoculant diversities increasing,maize grain yield increased and then decreased,and the average grain yield of two AMF mixed treatment highest.In the two experimental years,soil N2 O emission in maize growth period changed dynamically.In the experiment of the different species level AMF inoculants and their diversity,compared with CK,soil N2 O emission,cumulative emission and emission intensity of all AMF treatments were significantly decreased.The presence of A,B,C and D decreased N2 O emission by 14.0%,13.2%,14.0% and 14.6%,and cumulative emissions decreased by 13.8%,11.4%,12.8% and 13.0%,and emission intensity decreased by 42.4%,27.6%,34.4% and 33.9%,respectively.With AMF inoculant diversities increasing,soil N2 O emission and emission intensity decreased.In the different families level AMF inoculants and their diversity,compared with CK,soil N2 O emission,cumulative emission and emission intensity of all AMF treatments were significantly reduced.The presence of A,E and F decreased N2 O emission by14.0%,19.6%,and 21.1%,and cumulative emissions decreased by 13.8%,19.4% and19.0%,and emission intensity was reduced by 42.4%,37.3% and 34.6%,respectively.With AMF inoculant diversities increasing,soil N2 O emission and cumulative emission decreased,and the emission intensity decreased and then increased.In the experiment of the different species level AMF inoculants and their diversity,compared with CK,the accumulation of N,P and K in maize organs of all AMF treatments were significantly increased.With AMF inoculant diversities increasing,the accumulation of N,P and K increased and then decreased.In the different families level AMF inoculants and their diversity,compared with CK,the accumulation of N,P and K in maize organs in all AMF treatments were significantly increased.With AMF inoculant diversities increasing,the N accumulation in maize organs increased and then decreased,the P accumulation of maize grain,stem and leaf increased,the P accumulation in root and other parts increased and then decreased.Other parts K accumulative increased,the K accumulative of maize grain and roots increased and then decreased,and the K accumulative of leaf decreased.The results of correlation analysis showed that soil N2 O emissions,cumulative emissions and emissions intensity with AMF colonization,maize yield and the biomass(expected other parts biomass)has significant negative correlation,with soil NO3--N and INN content had significant positive correlation.These results showed that maize with different AMF could significantly increased grain yield and nutrient accumulation,and reduced soil N2 O emission,and Funneliformis mosseae was best on improved maize grain yield and nutrient accumulation.The increase of AMF diversities could significantly improved maize grain yield,and the four AMF species mixed treatments showed a better effect on grain yield,but had no significant effect on soil N2 O emission.The two AMF families mixed treatments had better on improving maize grain yield,and the three AMF families mixed treatments had the best on decreasing soil N2 O emission.In conclusion,the more AMF of different species,could better on improving maize grain yield,and the more AMF of different families,could better on decreasing soil N2 O emission.At the same time,suitable types of AMF should be selected to inoculated according to the purposes of high yield,high quality and sustainable development.