本文選題：腐殖質(zhì)　切入點：降雨強度　出處：《昆明理工大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：近年來,隨著公眾的環(huán)保意識的增強和國家對環(huán)境的污染治理的重視,社會各界越來越關(guān)心和重視土壤侵蝕或水土流失的治理。由于紫色土抗蝕性弱,分布區(qū)域的地形的起伏大,又地處亞熱帶,若遇到比較強的降雨,紫色土極容易造成水土流失,因而導(dǎo)致土壤養(yǎng)分的流失,土壤肥力的下降,和生產(chǎn)力的下降,嚴(yán)重地影響了當(dāng)?shù)厝嗣竦纳a(chǎn)和生活。本研究在系統(tǒng)的總結(jié)國內(nèi)外的相關(guān)研究資料的基礎(chǔ)上,以牟定颯馬場6種植被覆蓋下(桉樹林、針闊混交林、灌叢、暖溫性針葉林、落葉闊葉林、果園)的紫色土為研究對象,研究了 6種植被覆蓋下紫色土的理化性質(zhì)(包括pH值、總P、有效P、總N、有效N、有機質(zhì))和腐殖質(zhì)組分(包括胡敏酸、富里酸、胡敏素)剖面分布特征。以果園土壤為例,選擇3種不同降雨強度,在室內(nèi)進行土柱模擬試驗,研究腐殖質(zhì)碳量在水中的溶出特征,以及不同的降雨強度和不同的土壤深度對土壤腐殖質(zhì)碳量流失的影響。研究結(jié)果如下:(1)將土壤的剖面分為枯枝落葉層、0-10、10-20、20-30cm四個層次,按這個層次分別采集土樣,研究6種植被覆蓋下紫色土的理化性質(zhì)和腐殖質(zhì)的剖面分布特征。結(jié)果表明:枯枝落葉層的總P、有效P、總N、有效N、有機質(zhì)的質(zhì)量和腐殖質(zhì)(HS-C)、胡敏素(HM-C)、胡敏酸(HA-C)、富里酸(FA-C)的碳量顯著高于其它層。隨著土壤深度的增加,而總P、有效P、總N、有效N、有機質(zhì)、HS-C、HM-C、HA-C、FA-C的含量減小。不同的植被覆蓋方式下的牟定紫色土的土壤腐殖質(zhì)的碳量有顯著的差異。腐殖質(zhì)的平均碳量由低到高依次為:桉樹林果園針闊混交林暖溫性針葉林灌叢落葉闊葉林。腐殖質(zhì)、胡敏素、胡敏酸、富里酸兩兩相互之間均存在極顯著正相關(guān)關(guān)系(p0.01)。同時,腐殖質(zhì)、胡敏素、胡敏酸和富里酸與土壤有機質(zhì)、總P、有效P、總N、有效N均存在顯著正相關(guān)關(guān)系(p0.05)。(2)將降雨強度設(shè)置為0.5mm·min~(-1)、1mm·min~(-1)、2mm·min~(-1),研究不同的降雨條件下果園的土壤侵蝕對腐殖質(zhì)的溶出的影響。結(jié)果表明:3種降雨強度下的開始漏液的時間分別是499、338、176 min;總歷時分別為1639、1378、1088 min。每采集水樣 100 mL,在降雨強度為 0.5 mm·min~(-1)、1 mm·min~(-1)、2 mm·min~(-1)下需要的時間分別是30、20、7 min,因此侵蝕液相對應(yīng)的產(chǎn)流速率分別為3.33、5、14.29 mL·min~(-1)。說明降雨的強度越大,采樣的時間越少,侵蝕液相對應(yīng)的產(chǎn)流速率越快。在不同的降雨強度下,總有機碳、富里酸、胡敏酸碳量表現(xiàn)出來的溶出規(guī)律大體上是一致的,均呈現(xiàn)出先增大后降低的變化趨勢,而且隨著降雨強度的增大,它們相應(yīng)的溶出濃度也增大。當(dāng)降雨強度為0.5 mm·min~(-1)時,總有機碳、富里酸、胡敏酸碳量最大的溶出濃度分別是33.22±1.97、22.98±0.17、6.78±0.17mg·L-1。降雨強度為1mm·min~(-1)時,總有機碳、富里酸、胡敏酸碳量最大的溶出濃度分別是 68.89±1.13、22.98±0.19、8.52±0.23 mg·L-1。降雨強度為2mm·min~(-1)時,總有機碳、富里酸、胡敏酸碳量最大的溶出濃度分別是82.42±0.76、37.64±0.19、9.39±0.23mg·L-1。富里酸碳量在水中的溶出濃度大體上比腐殖胡敏酸大,這是因為富里酸在水中的移動性比胡敏酸大。在研究區(qū),不同降雨強度、不同土壤深度下的腐殖質(zhì)流失程度存在一定差異。降雨強度為2 mm·min~(-1)時,總有機碳、富里酸、胡敏酸的碳量減少率的范圍分別是40.7～45.8%、33.1～38.4%和54.7～59.2%,流失程度相對最劇烈。降雨強度為1mm.min~(-1)時,三者的碳量減少率的范圍分別是26.8～31.3%、23.4～27.3%和39.7～43.3%,流失程度相對次之。在降雨強度為0.5 mm·min~(-1)時,三者的碳量減少率的范圍分別是11.3～14.2%、10.3～12.3%和11.9～16.2%,流失程度相對最弱。腐殖質(zhì)碳量的流失程度在土壤深度為0-10 cm層時最嚴(yán)重,在土壤深度為10-20 cm層時次之,在土壤深度為20-30 cm層時相對最弱。因此總有機碳、富里酸和胡敏酸碳量的減少率隨降雨強度的增加而顯著增加,隨土壤深度的增加而減小。(3)以果園土壤為例,研究其不同深度土壤團聚體的分布,尋求耕作土壤結(jié)構(gòu)的抗侵蝕特征。果園紫色土的分形維數(shù)范圍在2.11～2.48之間,其中團聚體0-10、10-20、20-30 cm的分形維數(shù)分別是2.48、2.26、2.1 1。團聚體的分形維數(shù)隨著土壤深度的增加而降低,說明土壤結(jié)構(gòu)隨土壤深度的增加,其穩(wěn)定性越好。干篩0-10、10-20、20-30 cm的平均重量直徑(MWD)值分別是3.28±0.08、4.96±0.05、5.47±0.13mm,濕篩0-10、10-20、20-30cm的MWD值分別是2.38±0.07、2.47±0.05、2.7±0.11mm,濕篩團聚體的MWD值明顯低于干篩團聚體的MWD值,說明相對于干篩團聚體的MWD值來說,土壤結(jié)構(gòu)的穩(wěn)定性的狀況更應(yīng)該用濕篩團聚體的MWD值來反映。而無論是干篩還是濕篩情況下的MWD值表現(xiàn)出隨著土壤深度的增加而增大的現(xiàn)象,說明土壤的穩(wěn)定性隨土壤深度的增加越穩(wěn)定。(4)水土流失的調(diào)控措施:對于林地來說,保留地表植被和加大植被覆蓋度及合理利用空間布局是控制土壤侵蝕、養(yǎng)分徑流損失的行之有效的方法。間種綠肥、盡量保持土壤疏松和要開好排溝渠及合理使用有機肥等都可以提高果園的腐殖質(zhì)含量。
[Abstract]:In recent years, with the pollution of the environment of the public awareness of environmental protection and national attention from all sectors of society, more and more concern and attention for controlling soil erosion or soil erosion. Because the purple soil erosion resistance is weak, the distribution area of terrain, and is located in the subtropical zone, if encountered strong rainfall, purple the soil is likely to lead to soil erosion, resulting in the loss of soil nutrients, soil fertility decline, and decreased productivity, seriously affected the local people's production and life. The research based on summarizing the domestic relevant information system abroad. In 6 vegetation cover race Monding SA (under the Eucalyptus trees, coniferous forest, shrub, warm temperate coniferous forest, deciduous broad-leaved forest, orchard) in purple soil as the research object, studied the physicochemical properties of the 6 vegetation cover of purple soil (including pH value, total P, available P, total N, available N, organic matter) And humus (including Hu Min acid, fulvic acid, Hu Minsu) in orchard soil profile distribution characteristics. For example, a choice of 3 different rainfall intensity, soil column experiments indoors, the amount of carbon in humus on the dissolution characteristics of the water, and the effects of different rainfall intensities and different depth of soil erosion the soil humus carbon content. The results are as follows: (1) the soil profile is divided into the litter layer, four layers of 0-10,10-20,20-30cm, according to the level of soil samples were collected. The profile distribution of physicochemical properties and humic matter of 6 vegetation coverage in purple soil. The results showed that the total P branches the litter available P, total N, available N, organic matter and humus quality (HS-C), Hu Minsu (HM-C), Hu Min acid (HA-C), fulvic acid (FA-C) the carbon content was significantly higher than that of other layers. With the increase of soil depth, and total P, available P, total N. Available N, organic matter, HS-C HM-C, HA-C, FA-C, reduce the content of soil humus carbon content. Different vegetation under Monding purple soil had significant difference. The average amount of humus carbon from low to high as follows: Eucalyptus forest orchard coniferous forest and warm coniferous forest shrub deciduous broad-leaved forest. Humic matter, Hu the main, Hu Min acid, fulvic acid between 22 was significantly correlated (P0.01). At the same time, Hu Minsu, humus, humic acid and fulvic acid and soil organic matter, total P, available P, total N, there were significant positive correlation between N (P0.05) (2). The rainfall intensity is set to 0.5mm min~ (-1), 1mm min~ (-1), 2mm min~ (-1), study the different rainfall conditions of orchard soil erosion on humus dissolution effect. The results showed that 3 kinds of rainfall intensity to leakage time was 499338176 min in total; duration was 163913781088 min. per collection 姘存牱 100 mL,鍦ㄩ檷闆ㄥ己搴︿負(fù) 0.5 mm路min~(-1),1 mm路min~(-1),2 mm路min~(-1)涓嬮渶瑕佺殑鏃墮棿鍒嗗埆鏄，

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