發(fā)布時間：2019-06-03 20:07

【摘要】：為明確侵蝕性降雨條件下不同農(nóng)業(yè)措施對玉米季坡耕地水沙過程的影響及減沙效應(yīng),通過自然降雨條件下徑流小區(qū)觀測試驗(yàn),研究順坡耕作(CK)、橫坡壟作(CT)、橫坡壟作+秸稈覆蓋(CT+SM)、橫坡壟作+地膜覆蓋(CT+PM)、橫坡壟作+有機(jī)質(zhì)輸入(CT+OM)5種農(nóng)業(yè)措施對紫色土玉米季坡耕地徑流深、徑流系數(shù)、徑流曲線數(shù)、產(chǎn)沙量、土壤可蝕性指標(biāo)的綜合影響。結(jié)果表明,歷次降雨事件CK徑流系數(shù)變幅為18.89%~32.23%,CT+OM和CT+PM顯著削減了徑流量和產(chǎn)沙量,徑流量較CK減少15%~35%、泥沙量減少12%~75%。土壤可蝕性指標(biāo)隨降雨量和徑流量增加均呈增加趨勢,但增加幅度隨著降雨量或徑流量的增加而減小;土壤可蝕性與地表徑流量之間呈冪函數(shù)遞增關(guān)系,確定系數(shù)R2為0.70~0.87(p0.05);土壤可蝕性與降雨量呈對數(shù)曲線關(guān)系,R2為0.85~0.91(p0.05)。歷次降雨橫坡各處理土壤可蝕性指標(biāo)(Kw)顯著低于順坡壟作,CT和CT+OM的Kw均值分別為0.025kg·m~(-2)·mm~(-1)和0.023 kg·m~(-2)·mm~(-1),與CK相比平均分別減小17%和24%;CT+PM和CT+SM的Kw值最小,均值分別為0.021 kg·m~(-2)·mm~(-1)和0.018 kg·m~(-2)·mm~(-1),與CK相比分別減小29%和38%。綜上,橫坡壟作增加地膜覆蓋或秸稈覆蓋是控制紫色土玉米季坡耕地地表徑流、降低土壤可蝕性的有效措施。本研究為控制紫色土玉米季坡耕地水土流失、削減農(nóng)業(yè)面源污染負(fù)荷提供了理論依據(jù)。
[Abstract]:In order to clarify the effects of different agricultural measures on the process of water and sediment reduction in corn seasonal sloping farmland under erosive rainfall conditions, (CT), was studied by observing runoff plot under the condition of natural rainfall. (CT), on horizontal slope of slope tillage was studied by means of observation experiment of runoff plot under the condition of natural rainfall. Cross slope ridge mulching straw mulching (CT SM), horizontal slope ridge mulching plastic film mulching (CT PM), horizontal slope ridge cultivation organic matter input (CT OM) five agricultural measures on purple soil corn season slope cultivated land runoff depth, runoff coefficient, runoff curve number, sediment yield, Comprehensive effect of soil erodibility index. The results show that the variation of CK runoff coefficient is 18.89% and 32.23%, and the runoff and sediment yield are significantly reduced by CT OM and CT PM. Compared with CK, the runoff is reduced by 15% and 35%, and the sediment volume is reduced by 12% and 75%. The soil erodibility index increased with the increase of rainfall and runoff, but decreased with the increase of rainfall or runoff. There was a power function increasing relationship between soil erodibility and surface runoff, and the coefficient R2 was 0.70 鈮，

本文編號：2492193