【摘要】：黑土區(qū)的土壤侵蝕導(dǎo)致黑土質(zhì)量下降和作物減產(chǎn),嚴(yán)重威脅國家糧食安全。因此,研究黑土區(qū)土壤侵蝕對土壤質(zhì)量和作物產(chǎn)量的影響,為針對性的開展黑土資源保護(hù)提供重要科學(xué)依據(jù),也對保障國家糧食安全具有重要意義。本論文以典型黑土區(qū)黑龍江省哈爾濱市賓縣東山溝流域為研究區(qū),采用野外調(diào)查、室內(nèi)分析、核素示蹤和GIS技術(shù)相結(jié)合的研究方法,研究了流域土壤侵蝕空間分布特征,分析了流域土壤質(zhì)量主要指標(biāo)特征,基于指標(biāo)全集和最小數(shù)據(jù)集指標(biāo)評價了流域土壤質(zhì)量,剖析了土壤侵蝕對土壤質(zhì)量的影響,構(gòu)建了土壤侵蝕和土壤質(zhì)量對玉米產(chǎn)量影響的經(jīng)驗?zāi)Ｐ�。主要研究結(jié)論如下:(1)分析了黑土區(qū)流域土壤侵蝕—沉積空間分布特征。流域土壤侵蝕-沉積速率介于-7122.25~5471.70 t km-2 yr-1之間,平均值是-830.10 t km-2 yr-1,表明流域以侵蝕為主。在流域尺度,侵蝕和沉積呈交錯分布,流域上游以侵蝕為主,流域中游侵蝕與沉積并存,而下游地區(qū)主要發(fā)生沉積。在坡面尺度,坡中部侵蝕最嚴(yán)重,坡上部侵蝕較弱,而坡腳主要表現(xiàn)為沉積。流域侵蝕速率與坡度、坡長均呈極顯著的冪函數(shù)關(guān)系,而坡度對侵蝕的影響大于坡長。(2)闡明了流域土壤質(zhì)量指標(biāo)特征及其對侵蝕-沉積的響應(yīng)。分析的15個包含土壤物理學(xué)、化學(xué)和微生物學(xué)的土壤質(zhì)量指標(biāo)特征及空間分布特征,不同土壤質(zhì)量主要指標(biāo)空間分布趨勢不同。流域土壤質(zhì)量空間分布與流域侵蝕—沉積空間分布呈相反趨勢;土壤有機(jī)質(zhì)、全氮、堿解氮、速效磷、脲酶、堿性磷酸酶微生物量氮受土壤侵蝕影響顯著,說明土壤侵蝕是影響土壤養(yǎng)分、酶活性和微生物量的重要因素。(3)評價了流域土壤質(zhì)量水平。基于相關(guān)分析和主成分分析,選取15個土壤質(zhì)量主要指標(biāo)作為指標(biāo)全集,篩選出7個土壤指標(biāo)(黑土層厚度、土壤團(tuán)聚體平均重量直徑、有機(jī)質(zhì)、全氮、p H、堿性磷酸酶、微生物生物量氮)作為評價土壤質(zhì)量最小數(shù)據(jù)集指標(biāo)。基于指標(biāo)全集估算的流域和坡面土壤質(zhì)量綜合指數(shù)平均值分別為0.419和0.471。基于最小數(shù)據(jù)集評估流域和坡面土壤質(zhì)量綜合指數(shù)平均值皆為0.453,說明篩選的土壤質(zhì)量評價最小數(shù)據(jù)集指標(biāo)具有很好的代表性。兩種評價結(jié)果均表明流域土壤質(zhì)量以低等水平和較低水平為主,說明研究流域土壤質(zhì)量退化嚴(yán)重。土壤質(zhì)量在流域空間分布表現(xiàn)為:下游中游上游,在坡面分布表現(xiàn)為:坡下部坡上部坡中部。(4)研究了流域2009-2013年玉米產(chǎn)量特征及其空間分布。流域玉米產(chǎn)量在年內(nèi)和年間變化均存在差異。整個流域玉米產(chǎn)量表現(xiàn)為:下游中游上游。坡面玉米產(chǎn)量最大值分布在坡下部,最小值分布在坡中部。基于土壤質(zhì)量指標(biāo)全集(TDS)和最小數(shù)據(jù)集(MDS)評價的土壤質(zhì)量綜合指數(shù)均與玉米產(chǎn)量關(guān)系較好,但以最小數(shù)據(jù)集評價的土壤質(zhì)量綜合指數(shù)與玉米產(chǎn)量的關(guān)系更好,再次表明構(gòu)建的評價流域土壤質(zhì)量的最小數(shù)據(jù)集指標(biāo)有較好適宜性。(5)剖析了土壤侵蝕和土壤質(zhì)量對玉米產(chǎn)量的影響。流域和坡面兩個尺度上玉米產(chǎn)量空間分布與土壤質(zhì)量相對應(yīng),而其與土壤侵蝕空間分布呈相反趨勢。流域玉米產(chǎn)量與土壤侵蝕速率呈極顯著負(fù)相關(guān)關(guān)系,與土壤沉積速率關(guān)系不顯著;建立了土壤質(zhì)量與玉米產(chǎn)量的關(guān)系模型,且模型有效性較好。構(gòu)建了玉米產(chǎn)量與土壤侵蝕速率和土壤質(zhì)量綜合指數(shù)的關(guān)系模型。
[Abstract]:Soil erosion in black soil area leads to the decline of black soil quality and crop production, which seriously threatens national food security. Therefore, it is of great significance to study the effect of soil erosion on soil quality and crop yield in black soil area. Based on the research method of field investigation, indoor analysis, isotope tracing and GIS technology, this paper studies the spatial distribution characteristics of soil erosion in watershed, and analyzes the characteristics of main indexes of soil quality in watershed. Based on the index and minimum data set index, the soil quality of watershed was evaluated, the influence of soil erosion on soil quality was analyzed, and an empirical model of soil erosion and soil quality on maize yield was constructed. The main conclusions are as follows: (1) The spatial distribution of soil erosion in black soil area is analyzed. The rate of soil erosion-deposition is between -7122. 25-547t km-2yr-1, and the average value is-830. 10t km-2yr-1, indicating that the basin is mainly eroded. In the basin scale, erosion and sedimentation are distributed in a staggered way, the upper reaches of the basin is mainly eroded, and the erosion and deposition of the middle reaches of the basin coexist, while the downstream area mainly occurs. On the slope surface scale, the erosion in the middle of the slope is the most serious, the upper erosion of the slope is weak, and the slope foot is mainly characterized by the deposition. The erosion rate, slope and slope length of river basin are very significant, and the effect of slope on erosion is larger than that of slope. (2) Clarified the characteristics of soil quality index and its response to erosion-sedimentation. The characteristics of soil quality indexes and spatial distribution characteristics of 15 soil physics, chemistry and microbiology were analyzed, and the spatial distribution trends of different soil qualities were different. The spatial distribution of soil mass in the watershed is opposite to the distribution of sediment spatial distribution in watershed erosion. Soil organic matter, total nitrogen, alkali solution nitrogen, quick-acting phosphorus, phosphorus and alkaline phosphatase micro-microbial biomass nitrogen are affected by soil erosion, which indicates that soil erosion is the soil nutrient. Enzyme activity and microbial biomass are important factors. (3) The quality level of soil in the watershed was evaluated. Based on the correlation analysis and principal component analysis, 15 soil quality indexes were selected as indicators to select seven soil indexes (black soil layer thickness, average weight diameter of soil aggregate, organic matter, total nitrogen, p H, alkaline phosphatase, Microbial biomass nitrogen) was used as the minimum data set index for evaluating soil quality. The average mean value of soil mass index of watershed and slope was 0. 419 and 0. 471, respectively. Based on the minimum data set, the mean value of the soil quality index of the watershed and slope surface is 0. 453, which shows that the minimum data set index of the screened soil quality has a good representativeness. Both evaluation results show that the soil quality of the river basin is lower and lower, which indicates that the quality of soil in the study basin is seriously degraded. The spatial distribution of the soil in the basin is located in the middle reaches of the upper slope of the lower slope of the slope. (4) The characteristics of maize yield and spatial distribution in 2009-2013 were studied. There was a difference in the yield of maize in the watershed between the year and the year. The yield of maize in the whole river basin is as follows: upstream of the middle reaches of the downstream. The maximum distribution of maize yield at the slope surface is at the lower part of the slope, and the minimum value is distributed in the middle of the slope. The soil quality comprehensive index evaluated based on the soil quality index (TDS) and the minimum data set (MDS) was better than that of maize, but the comprehensive index of soil quality evaluated with the minimum data set was better than that of maize yield. It is shown that the minimum data set index of soil quality in evaluating river basin is good suitability. (5) The effects of soil erosion and soil quality on maize yield were analyzed. The spatial distribution of maize yield on the two scales of watershed and slope is corresponding to soil quality, but it is opposite to the spatial distribution of soil erosion. The relationship between the yield of maize and the rate of soil erosion was negatively correlated with the rate of soil deposition, and the relationship between soil quality and maize yield was established, and the model was good. The relationship model of maize yield and soil erosion rate and soil quality comprehensive index was established.
【學(xué)位授予單位】：中國科學(xué)院研究生院(教育部水土保持與生態(tài)環(huán)境研究中心)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：S157;S513
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本文編號：2305237