隔根与接种 FM 对红壤上玉米/大豆植株生长及氮素利用的影响

【目的】探讨接种摩西管柄囊霉 (Funneliformis mosseae，FM) 和不同隔根处理对红壤上间作植株生长、植株氮吸收量和土壤氮的影响。【方法】采用盆栽模拟试验，设不同菌根处理[不接种 (NM)、接种 (FM)]与玉米/大豆不同隔根处理 (根系不分隔、部分分隔、完全分隔)。【结果】接种 FM 的玉米、大豆根系均有一定的侵染，菌根侵染率在部分分隔处理下最低。间作根系的分隔处理对玉米和大豆的菌根依赖性产生了明显影响，大豆的菌根依赖性随间作交互作用强度的加大而增加。无论何种隔根处理，接种 FM 均显著增加了玉米植株生物量，其地上部生物量高出 NM 处理 11.7%～81.4%，根系生物量高出 NM 处理 18.8%～166.7%。根系分隔处理下，接种 FM 均显著降低了大豆生物量。同一隔根方式下，接种 FM 明显提高了玉米的植株氮吸收量和根系氮吸收效率。在不分隔处理下，接种 FM 显著增加了大豆的地上部氮吸收量，但在部分分隔和完全分隔处理下则反而有所下降；在部分分隔处理下，接种 FM 显著降低了大豆根系的氮吸收量，在不分隔和完全分隔处理下亦呈下降趋势。在部分分隔处理下，接种 FM 显著提高了大豆根系氮吸收效率，在完全分隔处理下反而有明显下降，且在 NM–不分隔处理下的大豆根系氮吸收效率最低。相关分析显示，玉米、大豆植株氮吸收量与土壤碱解氮含量呈显著负相关。【结论】接种丛枝菌根真菌 (AMF) 和隔根方式的组合能不同程度地影响玉米和大豆对氮的吸收利用及间作植株的生长，并能对土壤有效氮产生较大影响。所有的复合处理中，AMF和间作根系部分分隔处理组合对玉米和大豆生长及氮素利用的促进作用较好，并能有效降低土壤碱解氮的残留。

Effects of inoculating Funneliformis mosseae and intercropping under different roots separation methods on plant growth and nitrogen utilization of maize and soybean in red soils

[Objectives] This article explored effects of inoculating arbuscular mycorrhizal fungi (AMF) and different root separation methods on plant growth,nitrogen (N) uptake and available nitrogen content in soils.[Methods] Two mycorrhizal treatments [without inoculation (NM) and with inoculation of Funneliformis mnosseae (FM)] and three root separation methods (no separation,partial separation and full separation) were set up,and N uptakes by intercropping plants and available N contents in red soils were determined.[Results] Results showed that the roots of maizes and soybeans were all infected by FM fungi,the mycorrhizal colonization rates were the lowest under the partial separation treatment.The root separation methods had obvious influence on the mycorrhizal dependency of maize and soybean,and the mycorrhizal dependency of soybean was increased along with the increase of intercropping interaction strength.Compared to the NM treatment,the FM inoculation increased the shoot and root biomass significantly regardless of the roots separation methods,and the shoot biomass of maize inoculated with FM was 11.7％ to 81.4％ higher than the NM treatment and the root biomass of the FM treatment was 18.8％ to 166.7 higher than the NM treatment.The biomass of soybean was significantly decreased by the FM inoculation under root separation conditions.Under the same root separation way,FM inoculation increased the N uptake of maize plants and N uptake efficiency of roots obviously.Under no-separation condition,the N uptake by soybean shoots was increased by the FM inoculation significantly,but those were decreased under the partial separation and full separation conditions.Under the partial separation way,the N uptake by soybean roots was significantly decreased by the FM inoculation,and those were also decreased under the no-separation and full separation conditions.The N uptake efficiency of soybean roots under FM inoculation was increased under the partial separation condition,but it was decreased obviously under the full separation condition.The N uptake efficiency of soybean roots was the lowest under the NM and no-separation condition in all complex treatments.The available N contents in soils were significantly and negatively correlated with the N uptakes by maize and soybean plants.[Conclusions] The interactions between AMF inoculation and root separation methods could affect the growth and N uptake of maize and soybean in different degrees,and could also influence the available N contents in soils.Among all compound treatments,the enhanced effect of the combination treatment of the AMF inoculation and partial separation on maize and soybean growth and N utilization was the largest,and it could also decrease the available N contents in soils.