Development of sustainable and environmentally sound rice production technology using slags, iron containing materials

通过田间试验，考察了由炉渣组成的含铁材料（ICM）在减少稻田甲烷排放和提高水稻产量方面是否有效。在6种易还原性铁和易分解有机质含量不同的土壤中，施用ICM （1kg m^<-2>）可提高水稻产量，但不能缓解2年稻田的甲烷排放。与未使用ICM的土壤相比，所有商用ICM（10种材料）都增加了淹没水稻土（游离氧化铁含量低的冲积土）的甲烷产量。添加ICM增加甲烷产量的原因是ICM含有少量的可还原性氧化铁，并通过提高土壤ph来促进有机物分解。添加HCl可以改善ICM的性能。两种原ICM均能提高水稻产量和稻田甲烷排放量，但与未添加ICM相比，两种改质ICM使水稻植株硅含量和产量提高了34- 46%，甲烷排放量降低了10-41%。改良后的ICM不但没有提高水稻土的pH值，而且提供了大量的还原性氧化铁。这就是改良的ICM能减轻水田甲烷排放的原因。结论认为，改良含铁材料的应用是可持续和无害环境的水稻生产技术的有效选择。

A field study was conducted to examine whether iron containing materials (ICM) composed of slags were effective in mitigating methane emission from paddy fields and increasing rice production. Addition of ICM (1kg m^<-2>) increased the grain yield of rice but could not alleviate methane emission for two years in paddy fields of 6 soils with different levels of easily reducible ferric iron and easily decomposable organic matter. All of the commercial ICM tested (10 materials) increased methane productions from a submerged paddy soil which was alluvial soil with low content of free iron oxide, compared with the soil without ICM. Increase of methane productions by addition of ICM was derived from the facts that ICM contained small amounts of reducible Iron oxide and stimulated organic matter decompositions by raising soil pH. The properties of ICM were improved by adding HCl. While two kinds of original ICM increased the grain yields of rice and methane emission from paddy fields, two kinds of altered ICM increased silicon contents of rice plant and the grain yields by 34-46 % and decreased methane emission by 10-41% compared with no addition of ICM. The improved ICM did not increased pH of the paddy soil and supplied large amounts of reducible iron oxide. That is the reason why the improved ICM alleviated methane emission from submerged paddy fields. It was concluded that the application of improved iron containing materials was effective option as a sustainable and environmentally sound rice production technology.