菌根和间作对滇池流域红壤磷素迁移的影响

为了研究菌根和间作对滇池流域红壤磷迁移的减控影响,根据2013年5—10月采集的6次径流水样,通过田间小区试验,选取玉米大豆间作的红壤径流区,以单作玉米、单作大豆为对照,并设置抑菌处理(施用苯菌灵)和未抑菌处理,模拟分析间作和菌根处理复合作用下的径流磷迁移特征.结果表明:除7月19日外,整个雨季各处理下径流中ρ(TP)、ρ(可溶性磷)和ρ(颗粒态磷)随采样时间均无明显变化;所有组合处理中,未抑菌-间作处理下径流中ρ(TP)最低,比单作玉米、单作大豆分别降低25.6%、12.2%;无论是否抑菌,玉米大豆间作处理可使径流中ρ(可溶性磷)较单作玉米处理降低约24.7%;未抑菌处理下,玉米大豆间作处理径流中ρ(颗粒态磷)比单作玉米、单作大豆分别降低约14.3%、20.2%,并且在玉米大豆间作条件下,未抑菌处理径流中ρ(颗粒态磷)显著低于抑菌处理.另外,无论是何种种植模式,抑菌处理下土壤中w(TP)均显著高于未抑菌处理,增幅在9.0%以上;抑菌条件下,间作玉米处理下土壤中w(TP)、w(速效磷)较单作玉米处理显著降低;与抑菌-单作玉米处理相比,未抑菌-间作玉米处理下土壤中w(TP)和w(速效磷)也分别降低了0.25 gkg和2.56 mgkg.研究显示,菌根真菌协同玉米大豆间作体系可在一定程度上减少坡耕地红壤磷的径流流失,对滇池流域农业非点源污染具有一定削减潜力.

Effects of Mycorrhiza and Intercropping on Phosphorus Transference on Sloped Red Soil Land in Dianchi Watershed

Abstract: The objective of the present study was to investigate the influence of mycorrhizal inhibition and intercropping systems on reduction of P transport on red soil in Dianchi Watershed. A field runoff simulation experiment was conducted from May 25^th to October 21^stin 2013, the maize and soybean intercropping soil m runoff areas were selected, the mono-maize and mono-soybean control respectively were designed, and the mycorrhizal inhibition treatment (benomyl application can inhibit the growth of fungi) and none mycorrhizal inhibition (NM) treatment were designed respectively. The characteristics of runoff P transference after complex intercropping maize/soybean and mycorrhizal inhibition treatment were studied. The results showed that total P (TP), particulate P (PP) and soluble P (SP) concentrations in runoff water were not obviously changed over the sampling time in the rainy season except for July 19^th. The NM inhibition-intercropping treatment had the lowest TP concentration in runoff water among all the combined treatments. TP concentration in runoff for the intercropping treatment was lower 25.6% and 12.2% lower than for mono-maize and mono-soybean treatment under NM-intercropping conditions, respectively. Whether the mycorrhizal inhibition was applied or not, compared with the mono-maize treatment, intercropping decreased SP concentration in runoff about 24.7%. Under the NM inhibition treatment, PP concentrations in runoff for intercropping treatment were lower 14.3% and 20.2% lower than mono-maize and mono-soybean treatment, respectively, and under the intercropping treatment, PP concentration in runoff for NM inhibition treatment was lower than mycorrhizal inhibition treatment significantly. In addition, regardless of the plant modes, TP content in soil for the mycorrhizal inhibition treatment was lower 9.0% than NM inhibition treatment significantly. Under the mycorrhizal inhibition conditions, compared with the mono-maize treatment, intercropping maize treatment decreased the TP and available P content in soil significantly. Compared with the mycorrhizal inhibition-mono-maize treatment, the NM inhibition-intercropping maize treatment decreased the TP and available P content in soil by 0.25 g/kg and 2.56 mg/kg respectively. Compound mycorrhizal and intercropping treatment reduced P loss in runoff water to some extent on sloped red soil, and had a certain reduction potential on agricultural non-point source pollution in the Dianchi Watershed.