本文選題：常規(guī)耕作　切入點：免耕　出處：《農(nóng)業(yè)機械學報》2017年09期

【摘要】：為探明長期翻耕與免耕條件下不同土層深度土壤結構穩(wěn)定性及其有機碳分布特征,在長期定位試驗中分層(0~10 cm、10~20 cm、…、90~100 cm)采集免耕和常規(guī)耕作處理下混合土樣和原狀土樣進行土壤結構與有機碳的測定,結果表明:(1)隨著土層的加深,0.5~2.0 mm和大于2.0 mm粒級團聚體含量表現(xiàn)為逐漸降低的趨勢,而其他粒級團聚體含量呈增加趨勢。免耕更利于提高大粒級團聚體(0.5 mm)的含量,且土壤結構的穩(wěn)定性顯著提高,其作用深度在50 cm以上。(2)隨著土層的加深,土壤總有機碳和活性有機碳均表現(xiàn)為先增加后降低再趨于穩(wěn)定的趨勢。免耕處理在0~80 cm土層的土壤總有機碳和活性有機碳均高于常規(guī)耕作處理。(3)隨著土層的加深,不同粒級團聚體總有機碳含量呈降低趨勢,大粒級團聚體中含有較高的有機碳。免耕更利于0~40 cm土層不同粒級團聚體總有機碳含量的提高。隨著土壤團聚體粒級的降低,土壤活性有機碳含量呈降低趨勢。與常規(guī)耕作相比,除0.053~0.250 mm粒級團聚體外,免耕提高了0~20 cm土層各粒級團聚體中活性有機碳含量。(4)隨著土層的加深,各粒級團聚體中有機碳對土壤總有機碳的貢獻率表現(xiàn)為先降低后增加再降低的趨勢。不同粒級團聚體中,大于2.0 mm和小于0.053 mm粒級團聚體有機碳貢獻率在0~100 cm土層均低于其他粒級團聚體。在0~20 cm、30~40 cm和90~100 cm土層,免耕處理各粒級團聚體有機碳累積貢獻率均高于常規(guī)耕作。
[Abstract]:In order to find out the stability of soil structure and the distribution of organic carbon in different soil depth under long-term tillage and no-tillage. The soil structure and organic carbon of mixed soil samples and undisturbed soil samples under no-tillage and conventional tillage were determined in long-term location-oriented experiment, the soil structure and organic carbon were determined by stratification of 10 cm ~ (10 ~ (-1) ~ (10) ~ (10) ~ (10) ~ (20) cm, 鈥，

本文編號：1664747