分室磷添加下菌根对滇池流域红壤间作玉米生长及磷素利用的影响

随着全球范围内磷矿资源短缺问题的日益严重,间作或菌根技术强化作物对土壤磷(P)的利用及增产增收的效应受到越来越多的关注。通过三室隔网盆栽模拟试验研究了分室磷处理不添加磷(P0)、添加有机磷(OP50)、添加无机磷(IOP50)]和根室不接种(NM)、根室接种丛枝菌根真菌Glomus mosseae(GM)对与大豆间作的玉米的生长及磷素利用的影响。研究结果表明:所有复合处理中,以间作?GM?IOP50组合处理下的玉米根系最短和地上部生物量最高;OP50处理下,间作玉米的菌根侵染率显著高于单作处理。间作条件下,无论分室磷添加与否,接种GM处理的玉米地上部生物量明显高于NM处理;接种GM处理的玉米根系生物量和株高均显著高于NM处理,且根系生物量以间作?GM?OP50组合处理下最高。接种GM条件下,P0、IOP50、OP50处理下的间作植株生物量较单作处理分别提高45.98%、111.33%、33.56%。单作条件下,无论分室磷添加与否,接种GM处理的玉米地上部磷含量均显著高于NM处理;无论何种种植模式及分室磷添加与否,接种GM处理的植物根系磷含量均显著高于NM处理。无论磷添加与否,间作?GM组合条件下的玉米地上部磷吸收量均显著较高,其中IOP50处理下的地上部磷吸收量显著高于OP50处理。间作?GM组合条件下,IOP50处理玉米根系的磷吸收效率均显著高于OP50处理。可见,接种GM、分室磷添加和间作各自在一定程度上促进了玉米的生长。综合菌根侵染、生物量及磷含量与吸收量、磷吸收效率等指标,所有复合处理中以间作?GM?IOP50组合对玉米地上部的促生作用最好,玉米磷素吸收最多,可望有效强化滇池流域红壤坡耕地磷素的利用。

Effect of inoculation of AMF on plant growth and phosphorus utilization in intercropped maize under chamber phosphorus addition on red soils in Dianchi Watershed

Arbuscular mycorrhizal fungi (AMF) promotes growth of plants and increases utilization of phosphorus (P) and other nutrients of plants. Intercropping is an effective way promoting use efficiency of resources in both time and space. As the shortage of soil phosphate in different regions around the world worsens, more researches have focused on intercropping or mycorrhizal technology to strengthen soil P utilization and increase crop yield. Irrespectively, little has remained known about the effects of combined AMF inoculation and intercropping on plant growth and P utilization in sloping soils in Dianchi watershed. Plant growth and P utilization of maize (Zea mays L.) intercropped with soybean (Glycine max L.) or monocultured in red soils were investigated through the addition of different amounts of P to compartment chamber and different treatments of AMF inoculation in a root growth chamber. Three different P additions no P (P0), organic P (soy lecithin, OP50) and inorganic P (potassium dihydrogen phosphate, IOP50) with 50 mg(P)kg^-1 of soil, respectively] and two AMF treatments no AMF (NM) and Glomus mosseae inoculation (GM)] were set up. The results showed that among the composite treatments, both the shortest root length and largest shoot biomass of maize occurred under the GM-IOP50 intercropping treatment. For OP50 treatment, AMF infection rate of intercropped maize was significantly higher than that of monocultured maize. Regardless of P addition under intercropping, maize shoot biomass was obviously higher for GM treatment than for NM treatment. Then maize root biomass and plant height were significantly higher under GM treatment than under NM treatment. Root biomass was also highest under GM-OP50 intercropping treatment. For GM inoculation treatment, biomass for P0, IOP50 and OP50 intercropping treatments increased respectively by 45.98%, 111.33% and 33.56% over that of the corresponding mono-cropping treatments. With or without the addition of P under mono-cropping, P content in maize shoot was significantly higher for GM treatment than for NM treatment. Also irrespective of the mode of planting and addition of P, P content in maize root was significantly higher for GM treatment than for NM treatment. Regardless of P addition treatment, P uptake of maize shoot under intercropping with GM inoculation treatment was higher than that of the other treatments. Then shoot P uptake under IOP50 treatment was significantly higher than that under OP50 treatment. Under GM intercropping treatment, the specific absorption rate of P by maize root was significantly higher for IOP50 intercropping treatment than for OP50 intercropping treatment. Thus AMF inoculation, P application and intercropping modes respectively promoted plant growth to a certain extent. GM-IOP50 intercropping treatment performed best in terms of shoot growth and P uptake, which effectively strengthened P use in red soils in Dianchi Lake Basin.