外源磷与AMF菌丝对紫色土-玉米间作系统磷迁移的影响

摘要

丛枝菌根真菌(arbuscular mycorrhizal fungus,AMF)在植物与土壤系统中扮演着重要的角色,能促进宿主植物对养分尤其是磷的吸收,间作在提高土壤磷素利用及增产增收等方面具有重要作用.采用隔网分室盆栽模拟试验,根室设玉米单作及玉米-大豆间作处理,并分别进行不同AMF处理(不接种、接种Funneliformis mosseae,分别记为NM、FM),同时对分室进行不同磷处理(不施磷、施无机磷、施有机磷,分别记为P0、IOP50、OP50),研究不同形态外源施磷情况下AMF根外菌丝对间作玉米磷吸收、利用及累积的影响.研究结果表明,(1)FM-IOP50-间作组合处理下的玉米根系最短(16.76 m),生物量最高(1.88 g·pot-1),FM-OP50-间作组合处理下的玉米根系菌根侵染率最高,为66.25％.(2)在相同种植模式及磷处理下,FM处理的玉米根系及地上部生物量均明显高于NM处理;同一磷处理下,无论接种与否,间作玉米地上部和根系生物量均显著高于单作处理.(3)无论何种种植模式及磷处理,接种FM均提高了玉米植株磷含量及磷吸收量,均以FM-IOP50-间作组合处理下磷含量(0.68 mg·kg-1)和磷吸收量(15.97 mg·pot-1)最高;不管接种及分室施磷与否,间作玉米磷含量和磷吸收量均明显高于单作处理.(4)在同一种植模式及菌根处理下,IOP50处理的玉米根系磷吸收效率均显著高于P0及OP50处理.(5) FM接种、分室施磷和间作均在一定程度上促进了玉米植株生物量的增加及其对磷的累积.所有复合处理中,FM-IOP50-间作组合处理下的玉米磷含量和磷吸收量最高.可见,间作体系接种F.mosseae与外源无机磷施用组合是促进紫色土上玉米生长及磷吸收利用的最佳组合,有望通过降低土壤水溶性磷残留而减少径流磷的流失.%Arbuscular mycorrhizal fungi (AMF) in plant and soil systems play a large role,which can help the host plants to uptake nutrients,especially for phosphorus (P) absorption.More researches have focused on intercropping to promote use efficiency of P resources in soils and increase the crops yield.In this study,plant growth and P utilization of maize (Zea mays L.) intercropping with soybean or monocropping in purple soils were investigated through different P treatments to compartment chamber and different AMF treatments in root growth chamber.Two mycorrhizal treatments [no AMF (NM),Funneliformis mosseae inoculation (FM)] and three P treatment ways [none P addition (P0),inorganic P (potassium dihydrogen phosphate,IOP50) and organic P (soy lecithin),P 50 mg·kg1 soil respectively] were set up.The study explored p accumulation in maize and p absorption and utilization from soils under maize/soybean intercropping system through the three-compartment with net separation experiment.The main results as followed,(1) The results showed that among the composite treatments,both the shortest length and largest shoot biomass of maize occurred on the FM-IOP50 intercropping treatment (16.76 m and 1.88 g·pot-1).Largest AMF infection rate of maize roots was found for the FM-OP50 intercropping treatment (66.25％).(2) Under the same P treatment and planting mode,maize root and shoot biomass of FM treatment was obviously higher than the NM treatment.Regardless of FM inoculation or not under the same Ptreatment,shoot and root biomass of intercropped maize was significantly higher than the monocropping treatment.(3) Under the same P treatment and planting mode,FM inoculation increased the maize P concentration and P uptake.Both the highest plant P concentration and P uptake of maize occurred on the FM-IOP50-intercropping treatment (0.68 mg·kg-1 and 15.97mg·pot-1).Under the same P treatment and AMF treatment,intercropping increased the maize P concentration and P uptake.(4) Under the same planting mode and AMF treatment,P uptake efficiency of roots of IOP50 treatment was higher than that of the other P treatments.And (5) in conclusion,AMF inoculation,P application and intercropping respectively promoted P accumulation and plant growth to a certain extent.P concentration in and P uptake by maize plants were the highest under the FM-IOP50 intercropping condition among all combined treatments.Thus,the complex treatment of FM inoculation and inorganic P application under intercropping condition,was the best one for maize growth and P uptake,which could effectively decrease available P content in soil and further reduce runoff P loss.