长期稻油轮作改良土壤结构提高水稻产量

Long-term Rice-rice-rape Rotation Significantly Improved Soil Structure and Rice Yield

为研究长期稻稻、稻稻油不同轮作条件下土壤结构、土壤养分与水稻产量的关系。本文对经30年稻稻油(DDY)与稻稻(DDF)轮作的土壤养分、土壤质地和水稻产量进行研究。结果表明:长期稻稻油轮作土壤pH值、有机质、全氮含量均低于稻稻轮作,土壤全钾含量高于稻稻轮作;长期稻稻油轮作土壤伊利石含量低于稻稻轮作,而高岭石含量高于稻稻轮作,表明长期稻稻油轮作能提高土壤风化程度,促进土壤养分元素的释放;Clay:SOC值能较好表征土壤结构状况,且与SOC呈较好线性关系,长期稻稻油轮作土壤Clay:SOC值均低于稻稻轮作;长期稻稻轮作水稻年均产量为14346 kg hm^(-2),长期稻稻油轮作水稻年均产量为15254 kg hm^(-2),年均增产6.3%。因此,长期稻稻油轮作能显著改良耕层土壤结构,促进土壤养分元素的释放及水稻的氮肥利用率,从而显著提高水稻籽粒产量。

The contents of soil nutrients, soil structure and rice yield were analyzed after 30 years rice-rice-rape and rice-rice-fallow rotations in order to investigate their relationships with long-term rotation. The results showed that the pH value and the contents of soil organic matter and total nitrogen under long-term rice-rice-rape rotation were lower than that under long-term rice-rice-fallow rotation; Soil had lower illite content and higher kaolinite content under long-term rice-rice-rape rotation than under long-term rice-rice-fallow rotation. So long-term rice-rice-rape rotation could increase the degree of soil weathering and promote the release of soil nutrient. The ratio of clay to soil organic carbon（SOC） could characterize the soil structure very well and had a good linear relationship with SOC. The ratio of clay to SOC under long-term rice-rice-rape rotation was lower than that under rice-rice-fallow crop rotation.Therefore, the long-term rice-rice-rape rotation can significantly improve soil structure at plow layer, increase the release and accumulation of soil nutrients, and then improve rice yield.