有机,无机改良剂对酸性硫酸盐土化学动力学与水稻生长的影响

研究了稻秆、碳酸钙和二氧化锰改良剂对淹水的酸性硫酸盐土的电化学、化学动力学、水稻生长及产量的影响. 施用稻秆(干土重的0.25％)显著影响土壤的还原作用.高浓度的亚铁使水稻前期生长受阻;但亚铁的浓度随后逐渐降低,水稻生长繁茂,谷粒和茎秆产量反较高,植株的含钾量也增高. 加入酸酸钙(相当于干土重的0.25％)明显提高了土壤的pH值,降低土壤的Eh和EC值,并显著降低了水溶性亚铁、亚锰和铝的浓度.碳酸钙或碳酸钙加二氧化锰的处理,都能降低土壤溶液中亚铁的浓度,显著增加稻谷和稻杆的产量,此外,这两种处理都会降低生长前期植株中锌的含量. 加入二氧化锰(干土重的0.005％),使土壤溶液中的亚锰量增多,植株的铁锰比率降低,水稻产量比对照显著增加. 研究结果表明,稻杆是一种改良酸性硫酸盐土较经济的改良剂,其价值值得进一步研究.

THE EFFECT OF ORGANIC MATTER AND INORGANIC AMENDMENTS ON THE CHEMICAL KINETICS AND THE GROWTH OF RICE IN AN ACID SULFATE SOIL

Greenhouse experiments were conducted to determine the effects of straw, CaCO3, and MnO2 on the electrochemical and chemical kinetics and rice growth and yield in a flooded acid sulfate soil.Straw (0. 25% by weigh of the dry soil) application had a pronounced effect on soil reduction. High concentration of watersoluble Fe2+ stunted plants at early growth (but the Fe2+ concentration gradually decreased and plants had vig-orus growth at maturity. Grain and straw yields at harvest were higher. Potassium in the plant tissue was hight where straw was added.Adding CaCO2(0. 25% by weight of the dry soil) markedly increased soil soltuation pH,decreased Eh and EC,and significantly depressd concentrations of water-soluble Fe2+ ,Mn2+ and Al3+.Calcium carbonate,alone or in combination with MnO2,depressed Fe concentration in the soil solution and signficantly increased straw and grain yields. Calcium and MnOj applications also enhanced N and P content in the straw but decreased Zn content.Adding 0. 005% MnO2(by weight of the dry soil) increased the Mn in the soil solution,depressd the Fe:Mn ratio in the plant tissue,and increased grain yield significantly over the control. Results show that straw as an inexpensive amendment for acid sulfate soils merits further study.