Influencing Factors of the Mycorrhizal on Phosphorus Transport and Reduction in the Maize//Soybean Intercropping Red Soil of Dianchi Watershed

The objective of this study was to investigate the influencing factors of the mycorrhizal on phosphorus transport and reduction in the intercropping red soil of Dianchi Watershed. A field runoff simulation experiment was conducted, the intercropping soil of 1.6m20m runoff areas were selected, the mono-maize and mono-soybean control respectively were designed, and the mycorrhizal inhibition treatment(benomyl application can inhibit the growth of fungi) and none mycorrhizal inhibition(CK) treatment respectively were designed.The research results showed that, under intercropping and mono-soybean treatments, mycorrhizal inhibition treatment increased the concentration of total phosphorus in runoff. Regardless of the planting modes, mycorrhizal inhibition decreased the hyphal length density, and decreased total glomalin(TG) content in soil to a certain extent. In addition, except mono-soybean-CK treatment, CK treatment increased 0.25~2mm water stable aggregates in soil, the TG content in soil was higher in upper part of sloping fields. Under the mycorrhizal inhibition treatment, intercropping increased the content of 0.25 mm water stable aggregates in soil in different degrees. For the CK treatment, comparing with mono treatments, intercropping treatment decreased the concentration of total phosphorus in runoff, and intercropping treatment also increased the content of 0.25~2mm water stable aggregates in soil in a certain degree. In conclusion, for all treatments, the total phosphorus concentration in runoff under the intercropping-CK treatment was the lowest, and the hyphal length density under the intercropping maize-CK treatment was the highest, as well as the content of TG significantly was higher.