Abstract:In order to study the response of native arbuscular mycorrhizal fungi (AMF) and intercropping patterns to nitrogen (N) forms changes in runoff on red soil, different planting patterns (mono-maize, maize/soybean intercropping, mono-soybean) and different mycorrhizal treatments (mycorrhizal inhibition, none mycorrhizal inhibition) were designed by simulating runoff experiment under natural rainfall. The migration characteristics of N of different forms in runoff under the combined treatments of mycorrhizal and intercropping were analyzed using the six runoff water samples collected from June to September in 2017. The results showed that during the sampling times, the total N concentrations in runoff increased firstly and then decreased, while the concentrations of nitrate N showed a trend of increasing firstly, then decreasing and increasing again, and the ammonium N concentrations decreased firstly and leveled off then. Under all combined treatments, the total N concentrations in runoff was the lowest under the intercropping-uninhibited treatment, which was about 35.0% and 42.1% lower than those of mono-maize and mono-soybean under mycorrhizal inhibition treatments respectively. Regardless of the planting modes, the concentrations of nitrate N in runoff under the uninhibited treatment was lower than that of the inhibited treatments, which were significantly lower than those of mono-maize and mono-soybean under mycorrhizal inhibition treatments, the reduction rate were 26.2% and 33.9% respectively. Regardless of whether the mycorrhizal inhibition was applied or not, the concentrations of ammonium N in runoff with intercropping treatment were lower than those of mono treatments, which was the lowest under intercropping-uninhibited treatment. Compared with mono-corn and mono-soybean under mycorrhizal inhibition treatments, the reductions were 34.8% and 28.2% respectively. These results indicated that native AMF and intercropping treatments had a certain synergistic reduction potential for runoff nitrogen loss on red soil.