4种磷肥对土壤-叶菜类蔬菜系统中镉生物有效性的影响

Effects of four phosphorus fertilizers on cadmium bioavailability in soil-leaf vegetables systems

采用连续种植盆栽试验,以菠菜(Spinacia oleracea L.)、小白菜(Brassica rapa L.)和2种苋菜(Amaranthus mangostanus L.)为供试作物,研究4种不同磷肥对叶菜类蔬菜产量、吸收累积Cd量及对土壤Cd生物有效性的影响。结果表明:施用磷肥显著增加蔬菜产量,降低植株地上、地下部Cd含量,提高地上部Cd累积量,但施用磷肥处理间累积量差异不大;土壤有效态Cd含量与土壤pH呈显著负相关;4种磷肥酸化土壤能力大小为过磷酸钙(SSP)>磷酸二氢铵(MAP)、磷酸氢二铵(DAP)>磷酸氢钙(DCP);施用磷酸氢钙处理在4种蔬菜中的增产效果均表现最好,植株Cd含量最低,土壤pH最高,土壤有效态Cd含量最低。

A pot experiment was conducted to study the influences of four phosphorus on yield, cad- mium （Cd） absorption and accumulation in leaf vegetables （spinach,pakehoi,willow leaf and round leaf amaranth） and the Cd availability in soil. Results showed that phosphate treatments could significantly promote vegetables growth,reduce the Cd concentrations in vegetable shoots and roots and increase Cd accumulation in four vegetables shoots compared with the control treatment. However,the Cd accumu- lation in the shoots didn＇t varied significantly with the phosphate treatments. A significantly negative linear relationship was found between soil pH and the available Cd. The capability of four phosphates in acidifying soil varied in following order： SSP （superphosphate） 〉MAP （monoammonium phosphate）, DAP （diammonium phosphate）〉DCP （dicaleium phosphate）. The DCP treatment exhibited the highest yield, the lowest content of Cd in vegetable,the highest pH and the lowest soil available Cd.