磷肥施用对土壤中砷生物有效性的影响

通过盆栽试验,研究了钙镁磷肥和过磷酸钙对土壤砷的生物有效性的影响。结果表明,施用钙镁磷肥和过磷酸钙能显著促进小白菜的生长,与对照相比生物量分别提高了约149%和119%;施磷可显著提高土壤有效态砷含量,其中钙镁磷肥高、低施肥量处理分别比对照增加了52.2%和20.9%,过磷酸钙高、低量施肥处理比对照分别提高了15.0%和5.5%;在同一施磷水平下,钙镁磷肥处理的土壤中有效态砷含量明显高于过磷酸钙处理,施磷可导致小白菜对砷的吸收总量显著增加（P〈0.05）,施用钙镁磷肥处理的小白菜砷吸收量的增加幅度较大。磷肥施用可在一定程度上提高土壤中砷的生物有效性,其中施用钙镁磷肥比过磷酸钙的效果更为明显。

Effects of Phosphorus Fertilization on the Bioavailability of Arsenic in Soils

Effects of two kinds of phosphorus fertilizer including superphosphate（SP） and calcium magnesium phosphate（CMP） application on the growth of bok ehoy （Brassica chinensis ） and bioavailability of arsenic in soils were studied through a pot experiment. The results indicated that application of SP and CMP could significantly promote the growth of bok choy. Compared with the control （CK） treatment, the biomass of bok choy increased by 149% and 119%, respectively. The biomass of bok choy for the treatments with high P application rates was more than that for the treatment with low P application rate for these two kinds of phosphorus fertilizers. It was more beneficial to increase the biomass of bok choy with the treatment of CMP than that of SP. Application of phosphate fertilizer could increase the amount of available arsenic in soils, the increased percentage reached 52.2% and 20.9% respectively for the treatments of high and low application rates of CMP, while those for the treatments of high and low application rates of SP were 15.0% and 5.5%. At the same level of phosphate application, the available arsenic content in soils was significantly higher for the CMP treatment compared with that of SP treatment. The arsenic amount absorbed in bok chny significantly increased with application of phosphate application （P〈0.05）, and the CMP treatment showed higher increased amount of arsenic absorption in bok choy compared with other treatments. Therefore phosphate application could increase the arsenic bioavailability in soils to certain degree, and it was more obvious for the CMP treatment.