不同释放速率过氧化钙对模拟潜育环境下稻田土壤理化特性的影响

【目的】为探索缓释过氧化钙对潜育性稻田土壤的改良效果。【方法】于网室内进行潜育化稻田环境模拟试验，以不施、施过氧化钙粉末、施过氧化钙颗粒为对照，从已研发的10种不同包膜缓释过氧化钙中，选出4种缓释过氧化钙，探究其在水稻早稻分蘖期与收获期对潜育化稻田土壤中还原物质总量、活性还原性物质、还原性铁锰、有效养分等含量的变化的影响，以及对水稻整个生育期土壤pH、氧化还原电位、活性氧浓度动态变化的影响。【结果】结果表明，施用过氧化钙均能降低土壤还原物质含量，提高土壤速效养分含量和土壤pH、氧化还原电位及活性氧浓度。缓释过氧化钙的改良效果最佳，其次为过氧化钙颗粒和过氧化钙粉末。缓释过氧化钙处理中以乙基纤维素包膜效果最好，与不施过氧化钙处理相比，施用乙基纤维包膜过氧化钙和过氧化钙粉末处理下还原物质总量、活性还原性物质含量和还原性铁、锰含量分蘖期分别降低了22.9%和36.0%、20.5%和13.6%、37.7%和29.0%、38.8%和56.8%，收获期分别降低了32.4%和20.0%、32.7%和19.5%、34.3%和7.9%、25.5%和39.2%；其土壤pH平均分别提高13.1%和8.0%，土壤氧化还原电位与活性氧浓度平均分别依次提高34.3%和-11.3%及58.6%和13.4%。【结论】结果可为缓释过氧化钙在实际应用中对潜育化稻田的改良提供理论依据和实践基础。

Effects of Different Release Rates of Calcium Peroxide on Physicochemical Properties of Paddy Soil Under Simulated Gley Environment

The environmental simulation experiment of gleyed paddy field was carried out in net lab in order to explore the effect of slow-release calcium peroxide on the improvement of gleying paddy soil. Four kinds of slow-release calcium peroxide were selected from 10 kinds of coated slow-release calcium peroxide. The total content of reducing substances in the soil of gley fertile paddy field was investigated in rice tillering and harvest stages, and the changes of active reductive substances, reductive ferromanganese, effective nutrients and the dynamic changes of soil pH, redox potential and reactive oxygen concentration during the whole growth period of rice were also studied. The results showed that calcium peroxide could reduce the contents of soil reduction substances in the sampling period, and could improve the contents of available nutrients and soil pH, redox potential and reactive oxygen concentration in soil. Slow-release calcium peroxide had the best effect, followed by calcium peroxide granules and powders. The effect of ethyl cellulose coating was the best in the treatment of slow-release calcium peroxide, compared with the treatment of ethyl fiber coated calcium peroxide and calcium peroxide powder, the total content of reducing substance, the contents of active reductive substance, reductive iron and manganese were reduced by 22.9% and 36.0%, 20.6% and 13.6%, 37.6% and 29.0%, 38.7% and 56.9% in tillering stage respectively, decreased by 32.4% and 20.0%, 32.7% and 19.5%, 34.3% and 7.9%, 25.5% and 38.6% in harvest stage respectively; soil pH increased by 13.5% and 8.3% respectively, soil redox potential and reactive oxygen concentration increased by 43.0% and 2.2%, 58.6% and 13.4% respectively. The above results can provide theoretical and practical basis for the improvement of gleying paddy fields by slow-release calcium peroxide.