厢沟免耕秸秆还田对作物及土壤的影响

以常规翻耕为对照,通过2 a的双季稻田厢沟免耕秸秆还田试验发现,厢沟免耕水稻的前期生长较快,分蘖期缩短,而灌浆结实期较长,全生育期免耕比翻耕多1~2 d;油菜两年产量增加,水稻第1年产量变化不大,第2年产量增加。厢沟免耕土壤容重先增后减,有机质先减后增,土壤自调期不足1 a;在土壤各土层分布上,与传统免耕不同,厢沟免耕各土层差异不明显,0~5 cm土层土壤养分富集不明显,15~25 cm土层土壤容重显著降低,有机质比对照增加55.23%。秸秆还田能降低翻耕土壤容重,增加土壤有机质,而对免耕土壤影响不明显。

Effect of Ditch No-Tillage and Straw Recycling on Rice Yield, Soil Bulk Density and Organic Matter

Two-years' experiments in double-cropping rice field were conducted.Results showed that the ditch no-tillage and straw returning,compared with the conventional tillage,made rice grow faster and the tillering stage end earlier.But the filling and productive stage was longer with the total growth stage 1~2 days longer.The yield was higher in both years.Yield of rice changed little in the first year and began to increased in the next year.The bulk density under ditch no-tillage increased first,then decreased,while the content of organic matter first decreased,then increased,the soil self-adjusted stage was less than one year.Unlike the conventional no-tillage,the difference among soil layers was not apparent,the nutrient enrichment under ditch no-tillage was obvious in 0~5 cm soil layer,but the bulk density was significantly decreased in 15~25 cm soil layer.The content of organic matter was 55.23 percent more than that of CK.Straw recycling can decreased bulk density and increased the content of organic matter in conventional tillage,but the effect on that of no-tillage with ditch was not so significant.