Study On The Relief Effect Of Rhizobium Inoculation On The Obstacles Of Replanting Pea

In order to explore the effect of alleviating obstacle of pea continuous cropping by inoculating with rhizobia,screen the rhizobia with application potential,and provide a theoretical basis for the research on the obstacle of pea continuous cropping.In this experiment,two different varieties of pea(L6: Longwan 6 and D8: Dingwan 8)were planted in a regular and repeated cropping manner using pot culture to inoculate a single bacteria(R1:ACCC15657,R2: ACCC15735,R3: Wa32)and mixed bacteria(R4:ACCC15657+ACCC15735,R5: ACCC15657+Wa32,R6: ACCC15735+Wa32,R7:ACCC15657+ACCC15735+Wa32)as experimental treatments,and non-inoculation as a control.To study the effects of rhizobia on the growth indexes,photosynthetic indexes and the number of root microbes in different growth periods(seedling,flowering,and mature)of pea plants grown in stubble and continuous cropping,and to provide a scientific basis for exogenous inoculation of rhizobium bacteria as biological fertilizer to alleviate the obstacle of recropping of pea plants.The results are as follows:1.Repeated cropping of different pea varieties had different effects on the growth indicators at different periods.Compared with normal cropping,the plant height of L6 flowering period and D8 growth period decreased by 26.5%,14.4%,17.3% and 16.8%,respectively;L6 and D8 above ground the biomass in the seedling stage decreased by 18.2%,35.3%,and in the flowering stage by 26.8%,18.9%;the biomass of the underground portion of L6 decreased by 51.8% in the flowering period;the root length decreased by 25.3% and44.5% in the flowering period of L6 and D8;L6 root surface area decreased by 39.5%,22.4%during flowering and mature periods,and D8 had no significant difference in each growth period;root shoots increased by 36.9%,46.0%,34.6,36.2% compared with L6 seedling and D8 growth periods;L6 and the chlorophyll content of D8 decreased by 13.6% and 16.2% at the flowering stage;the Pn value of L6 at the seedling and flowering stage decreased by 29.4%and 76.3%;the Gs value of L6 and D8 increased by 93.6% and 55.2% at the flowering stage;the Tr values of L6 and D8 increased by 101.9% and 107.8% at the flowering stage,and decreased by 16.4% and 75.5% at the maturity stage;the Ci values of L6 and D8 increased significantly at the seedling and flowering stage,and decreased significantly at the maturity stage;the number of L6 and D8 bacteria decreased by 36.9% and 39.9% respectively during the mature period;the number of fungi in the two pea varieties decreased significantly in each grow period;the numbers of L6 and D8 actinomycetes increased by 92.0% and 86.1%respectively during the mature period.2.Inoculation of rhizobia is beneficial to the growth of pea plants in the stubble and continuous cropping.Different rhizobia had different effects on different pea varieties.Inoculation with single rhizobia R2 in direct cropping had the most obvious promotion effect on the growth index of L6,and the treatment with mixed inoculation R5 had the best promotion effect on the photosynthetic index of L6;repeated cropping and mixed inoculation with R5 had the best effect on the growth index of L6.Inoculation of R1 had a better effect on L6 photosynthetic index.The effect of mixed inoculation with R7 on the growth index of D8 was obvious,and the mixed inoculation with R6 had the best effect on the photosynthetic index;the repeated cropping with the mixed inoculation R4 had the best effect on the growth index,and the single inoculation R1 had the best effect on the promotion of D8 it is good.The number of bacteria and actinomycetes treated with rhizobia inoculation increased,and the number of fungi tended to decrease.3.Correlation analysis of various growth indicators found that L6 plant height was significantly positively correlated with above-ground biomass and underground biomass,and above-ground biomass was extremely significantly positively correlated with root length,and underground biomass was significantly correlated with total root surface area and roots.Crown ratio showed a very significant positive correlation,root length and total root surface area showed a very significant positive correlation,Pn had a significant positive correlation with Gs and Tr,Gs had a very significant positive correlation with Tr,and the number of bacteria had a very significant positive correlation with the number of actinomycetes.D8 underground biomass was significantly positively correlated with root-shoot ratio,root length was extremely significantly positively correlated with total root surface area,root-top ratio was significantly negatively correlated with the number of Pn,Gs,and bacteria during flowering and maturity,and Pn was significantly negatively correlated with Gs and Tr were significantly positively correlated,and Gs and Tr are extremely significantly positively correlated.Repeated pea planting seriously inhibits the growth and development of pea.Rhizobium inoculation can increase the growth and photosynthetic indicators of pea plants in the stubble and continuous cropping,and increase the number of beneficial microorganisms.However,there are differences between different rhizobia,different pea varieties and different planting methods.Therefore,the selection of the dominant rhizobia inoculated with strong compatibility with leguminous crops can be used as one of the measures to alleviate the obstacles to repeated cropping.