Effects Of AM Fungi And Amendments On The Growth Of Nitraria Sibibica And Improvement Effect Of Sandy Soils

Soil desertification is an important environmental issue of common concern all over the world.Current studies mainly focus on the improvement effects of different amendments on sandy soils.AM fungi are the most widely distributed symbiotic fungi in the soil.The effects of AM fungi combined with amendments on plant growth and improvement effect of sandy soil have rarely been reported.In this study,pot experiments in greenhouse were used to study the effects of AM fungi and three amendments,including biochar(BC),organic fertilizer(OF)and humic acid(HA),on plant growth and soil substrate in sandy soils.The sandy soil of Inner Mongolia grassland was collected as culture medium and Nitraria sibirica was selected as plant species for sandy soil improvement.The experiments results showed that:(1)The symbiotic relationship between AM fungus Rhizophagus intraradices and root system of Nitraria sibirica was successfully established in sandy soil with different amendments.The mycorrhizal infection rate was 15.22%~28.17%.The inoculation of AM fungi significantly increased the total dry weight of Nitraria sibirica by 22.6%~113.8% in control and OF,HA,BC+OF treatments,and increased respectively the contents of Nitraria sibirica N,P,K,Ca and Mg by117.5%~191.9%?106.5%~538.9%?31.9%~89.6%?91.6%~164.1%?17.8%~138.9%in control and BC,HA,BC+OF,BC+HA treatments.(2)The inoculation of AM fungi significantly increased respectively the totalN,P and K concentrations of sandy soils by 152.5%?10.7%~63.2%?13.5%~92% in BC,HA and BC+OF treatments,and the available N,P and K concentrations of sandy soils increased respectively by 60%?26.5%~189.2%?24.3%~45.3% in BC,OF,HA and BC+HA treatments.(3)The inoculation of AM fungi significantly increased the micro-aggregates of 2-0.25 mm,0.05-0.01 mm of sandy soil by 47.9% and 37.8% in BC treatment,and the micro-aggregates of 0.05-0.01 mm increased by 35.9% in BC+OF treatment,and in BC+HA treatment the micro-aggregates of 0.05-0.01 mm increased by 35.1%.(4)The activities of urease,phosphatase and catalase of sandy soils in BC,OF and BC+OF treatments increased respectively by 61.5%~86%?53.8%~231.9%?12.7%~30.1% by inoculating AM fungi,and the water content of sandy soils in BC treatment increased by 9.8%.There was no significant effect on the density of sandy soils with amendments.The EC value of sandy soil decreased by 37.61%~58.18%after planting Nitraria sibirica with AM fungi and amendments.The results showed that inoculation of AM fungi could significantly improve plant growth and soil substrate improvement under the condition of single or mixed application of amendments,which showed that the combination of microbial and physicochemical remediation measures were more conducive to promoting the effect of plant modification of sandy soil and providing scientific basis and technical support for the future large-scale ecological remediation of sandy soil.