【摘要】 为了研究土著丛枝菌根真菌(arbuscular mycorrhizal fungi, AMF)与间作模式对坡耕地红壤径流氮形态变化的响应,通过自然降雨条件下的径流小区模拟试验,设置不同种植模式(单作玉米、玉米/大豆间作、单作大豆)和不同菌根处理(抑菌(喷施苯菌灵)、未抑菌)进行研究。根据2017年6—9月采集的6次径流水样,分析比较菌根与间作复合处理下径流氮形态变化迁移特征。结果表明:在6次取样时间内,地表径流总氮浓度呈先上升后下降的趋势,硝态氮浓度呈先上升后下降再上升的趋势,而铵态氮浓度则表现出整体下降的趋势,并趋于平缓。所有复合处理中,间作-未抑菌处理的径流总氮浓度最低,较单作玉米-抑菌与单作大豆-抑菌处理显著降低35.0%和42.1%。无论何种种植模式,未抑菌处理的径流硝态氮浓度均明显低于抑菌处理,其中间作-未抑菌处理的径流硝态氮浓度较抑菌处理下的单作玉米与单作大豆处理显著降低,降幅分别为26.2%和33.9%。无论是否抑菌,间作处理的径流铵态氮浓度均低于单作玉米与单作大豆处理,间作-未抑菌处理下其浓度最低,较单作玉米-抑菌与单作大豆-抑菌处理明显降低34.8%和28.2%。由此可见,土著AMF与玉米/大豆间作对径流氮流失具有一定的协同削减潜力。更多还原

【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.更多还原