Effects Of Soil Amendments And AM Fungi On Maize Growth In Saline Soil

Soil salinization is a common problem in the world.It is related to the use of land resources,crop production and agricultural development.The salinized soil in Inner Mongolia is widely distributed.Due to the development and utilization of mineral resources and the influence of pastoralism in pastoral areas,the area of cultivated land has been reduced year by year.As a land resource,saline soil has a very broad application prospect.At present,the study of saline soil is mainly aimed at the improvement of soil matrix,while the study of saline soil improver focuses on the screening of modifiers and the mixed application of various modifiers,but does not focus on the use of saline soil.Especially,it has not focused on the use of saline soil and the determination of crop growth and related indicators on saline soils,and there has been little report on the mixed application of AM fungi and soil amendments.In this study,maize(Zea mays L.)was selected as the tested plant.The non-polluted soil in the nursery area of Hohhot was used as the substrate for plant growth.The saline soil was simulated in the form of later salting.A greenhouse pot experiment was conducted to study the effects of different amendments or improvers combined with AM fungi inoculation on maize growth,nutrient elements,salt ion uptake,C:N:P ecological stoichiometry,soil pH,electrical conductivity,and diameter distribution on saline soil.At the same time,the physiological and biochemical indicators of the plant were analyzed in order to reveal the mechanism of action of the modifier and mycorrhiza.The purpose of this paper is to investigate the effects of amendments on crop growth and salt tolerance in saline soils,and the effects of combination of modifier and arbuscular mycorrhizal fungi inoculation on crop growth were studied,and it aims to provide basic data and theoretical support for the development and utilization of saline soil.The results showed that,the arbuscular mycorrhizal fungi formed a good symbiotic relationship with the roots of maize under the treatment of various modifiers,and the mycorrhizal infection rate was between 37.6%and 46.7%.Applying amendments increased the shoot,root and total dry weight of maize,and only PAM increased the dry weight of maize significantly by 22.7%.The application of biochar increased P concentrations in shoots and roots of maize plants by 68.5%and 91.2%,and significantly increased P/K~+and root K~+/Na~+,P/K~+by 100.0%,60.8%and 50.0%,respectively.The Na~+concentration in shoots and roots decreased significantly by 17.9%and 29.2%,respectively.All treatments increased the protein concentration of corn leaf significantly by 81.6%to 116.3%.The soluble sugar content of maize leaves increased,but the effect of proline content was not significant.All treatment decreased the soil p H value,and only PAM treatment reduced the soil electrical conductivity by 7.89%.All treatments increased the soil particle size of 2~0.25 mm by 1.77%to 18.59%,and decreased the soil content of0.25~0.05 mm by 3.68%to 14.74%,and decreased the soil content of 0.05~0.01 mm by 2.02%to 4.38%.The results showed that inoculation of AM fungi under improvers treatment increased the P concentration in shoots and roots of maize by 91.1%to 110.5%and72.1%to 107.4%,respectively.And affected the ecological stoichiometric ratio of C:N:P to a different extent,the shoot N:P,C:P and root N:P,C:P decreased by 47.7%to 60.0%,48.1%to 51.5%and 32.8%to 47.7%,47.0%to 56.0%,respectively.The shoot K~+/Na~+,P/K~+and root P/K~+increased significantly from 482.8%to 767.1%,100.0%to 150.0%and 75.0%to 100%,respectively.And the shoot Na~+concentration decreased significantly by 81.5%to 85.5%.The application of PAM and inoculation of AM fungi significantly reduced the content of MDA in maize leaves by 16.91%.The effect of PAM on the content of osmolytes in maize leaves increased.All treatments increased the chlorophyll content of maize leaves significantly.Among them,application of biochar increased chlorophyll b and total chlorophyll content significantly by 140.0%and 137.0%.Applying PAM significantly increased chlorophyll b and total chlorophyll content by 140.0%and142.6%.The application of the amendment and inoculation of arbuscular mycorrhizal fungi did not have the same effect on chlorophyll.Applying only PAM and inoculating arbuscular mycorrhizal fungi significantly increased the content of chlorophyll a,chlorophyll b and total chlorophyll in maize leaves by 78.1%,69.4%and 77.1%,respectively.The preliminary test showed that,the three modifiers promote corn growth.The application of amendments,especially biochar,is important for increasing salt tolerance in plants,inoculation of AM fungi can also enhance the ability of plants to resist salt stress,and promote the utilization of salinized soil for agriculture.