硅对酸性土壤铝毒的缓解作用

Alleviating Effect of Silicon on Aluminum Toxicity to Wheat Growth in Acid Soil

铝毒是酸性上壤限制作物生长的主要因素，寻找缓解甚至消除土壤铝毒的措施是合理开发利用酸性土壤、提高作物产量的重要途径。本试验选取湖北温泉第四纪母质发育的酸性红壤（ｐＨ值４．８），作了加硅处理的小麦土培和根际培养试验，测定了麦苗植株生长量、部分矿质元素含量以及根际土壤活性铝的含量。结果表明，加硅０．３ｍｍｏｌ／ｋｇ即可促进麦苗根系对钙、镁等元素的吸收，增加植株的生长量。硅加入量达到０．９ｍｍｏｌ／ｋｇ时，对麦苗生长和矿质养分吸收的促进作用更加明显。加硅处理还在一定程度上减缓了麦苗根际土壤ｐＨ值下降和活性铝增长的幅度。本文讨论了酸性土壤上施用含硅物料缓解铝毒的作用及其应用的前景。

Pot culture experiments were carried out to studythe effect of silicon application in acidic soil on thealleviation of aluminum toxicity to wheat. Siliconwas added as solutions of sodium slilicate with aPH value of 4. 8 and the unamended soil was usedas control. Plant biomass and contents of someelements in wheat seedlings were measured. Theconcentrations of some species of active aluminumin rhizosphere soils were also determined. It wasfound that the biomass of wheat seedlings increased and the uptake of Ca, Mg etc. by wheatseedlings was. improved with 0. 3 mmol/kg of Siadded. When the amount of St added reached 0. 9mmol/kg, more significant effects can be ob--served for the growth and uptake of nutrients bywheat seedlings. Moreover, silicon tretmentsslowed down the PH decline and the increment ofsoluble and exchangeable aluminum content inrhizosphere soils. Considering the resources andthe effects for mitigating aluminum toxicity, application prospect of silicon materials such as someindustrial waste products and crop residues in acidsoils were discussed.