菌根技术对磷石膏农用的强化效应

Strengthening effect of mycorrhizal technology on application of phosphogypsum in agriculture

磷石膏资源农业利用的可行性已成为磷复肥生产实现可持续发展的关键,而菌根技术的引入可能是磷石膏在低硫缺磷土壤上农用的有效新途径。该文以小葱(Allium schoenoprasumL.)为供试植物进行模拟试验,研究添加不同量(0、20、40g/kg)磷石膏(phosphogypsum,PG)和接种不同丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)(Glomus mosseae、Glomus aggregatum、Diversispora spurcum)对其生长及磷、硫、砷吸收的影响。结果表明:小葱植株生物量、磷、硫、砷含量及磷砷吸收比均随磷石膏添加水平的提高而有增加趋势。与未接种相比较,在添加了磷石膏的基础上接种上述AMF均能不同程度改善小葱生长并促进其磷素养分的吸收,而添加40g/kg磷石膏(PG40)处理接种Glomus mosseae(GM)和Diversispora spurcum(DS)的宿主植株砷含量显著较低,其中以PG40-GM组合处理的小葱生长量、磷、硫吸收量及磷砷吸收比最大,在缺磷低硫土壤上促生效果最好。PG20添加水平时接种上述任意AMF后的小葱砷含量明显降低(且在食品砷限量标准范围内);而PG40添加水平时只有接种DS的小葱砷含量基本在限量标准之内,且抗砷效果较好。

Phosphogypsum （PG） is one of the largest industrial solid wastes, which stacked on the open yard could pose many environmental risks. Meanwhile, PG contains phosphorus （P）, sulphur （S） and the other plant-essential nutrient elements, so that the application feasibility of PG in agriculture is very important for sustainable development of phosphate fertilizer and complex fertilizer industry. PG also contains harmful substances for human body such as arsenic （As）. Mycorrhizal fungi may play an important role in protecting plants against As uptake under As and other heavy metals stress. Therefore, the introduction of mycorrhizal technology may become an effective and new way of application PG to the soil with P deficiency and low S. A pot experiment was conducted to study the plant growth and P, S and As uptake by shallot （Allium schoenoprasum L.） under 3 different PG addition levels （0, 20, 40 g/kg） （PG0, PG20, PG40） and inoculating 3 different arbuscular mycorrhizal fungies （AMF） （Glomus mosseae （GM）, Glomus aggregatum （GA）, Diversispora spurcum （DS））. This objective of this research was to explore the potential utilization value of PG compound with mycorrhizal technology to agricultural soil for Southern China. Furthermore, the experiment was carried out in the plastic greenhouse located at Yunnan Agricultural University in November 2010. The samples were harvested after plant growth for 14 weeks. Mycorrhizal colonization rate, dry weight, P, S and As concentrations in shallots were determined. SPSS11.5 statistical software was used for analyzing the interactions for PG addition and AMF inoculation treatments. The results showed that a low root colonization rate （30%） was detected. The biomass of shallot was increased with the increasing PG additive levels. Concentration of P, S and As in shallots also increased with the increasing PG additive levels. For PG20 and PG40 treatment, GM, GA and DS colonization respectively can improve plant biomass and P uptake by shallot at different degrees. Comparing with corresponding control treatments, the treatment of PG40 addition together with GM inoculation had a significant effect in improving shallot biomass and P, S uptake. This treatment had the best growth-promoting effect in soil with P deficiency and low S. Meanwhile, the uptake ratio of P to As in shallot was the highest for GM inoculation with PG40. As concentrations in shallot were decreased significantly in the treatments of GM and GA inoculation with PG20, which were lower than the national arsenic limit standard for food. However, As concentration in shallot with PG40 combined with DS inoculation was in food arsenic limited standard, which showed the most obvious anti-arsenic effect. Therefore, the PG40-DS combined treatment and PG20 with AMF inoculation appeared the perspective for promoting PG use and ensuring food security. When PG application rate of advantage anti-arsenic treatment is 20 and 40 g/kg soil, respectively, the application amount of 2700 and 5400 kg per acre will be expected to be used to solve some problems from PG stacking on the field.