【摘要】：黑龍江省是我國重要的糧食生產(chǎn)基地,由于地處我國東北部氣候寒冷且人均水資源量低于全國水平,水資源的短缺嚴(yán)重制約了我省各項(xiàng)工業(yè)與農(nóng)業(yè)的發(fā)展。尤其在我國農(nóng)業(yè)耕作方式相對(duì)落后,水資源利用率僅為45%落后于很多發(fā)達(dá)國家,則有效的利用現(xiàn)有土地資源與水資源顯得尤為重要,節(jié)水灌溉提高農(nóng)業(yè)單產(chǎn)以成為國家糧食安全最重要的問題之一。本文針對(duì)于我國東北部寒冷地帶,以冬季大田試驗(yàn)觀測(cè)數(shù)據(jù)為根據(jù)對(duì)冬季不同秸稈覆蓋處理下土壤水分與溫度的變化規(guī)律進(jìn)行分析,意圖提出適宜的覆蓋方案為春季春耕防止春旱做準(zhǔn)備。通過對(duì)于試驗(yàn)數(shù)據(jù)的分析得到的研究結(jié)果如下:(1)秸稈覆蓋作為一種阻礙土壤與大氣熱量交換的介質(zhì),對(duì)于熱量由土壤之中散發(fā)至大氣中、大氣之中的熱量傳遞到土壤之中均有一定的阻礙作用。但又由于在不同的氣溫條件下熱量運(yùn)移的方向不一致,使得秸稈覆蓋對(duì)于土壤溫度的調(diào)節(jié)作用不同,由此土壤溫度的變化趨勢(shì)總是滯后于大氣溫度的變化趨勢(shì)。由于表層土壤與大氣接觸相對(duì)比較密切,所以外環(huán)境的變化對(duì)于表層土壤的影響效果顯著。隨著土壤深度不斷的增加熱量傳遞的消耗量與時(shí)間所占的比重逐漸變大,所以不同秸稈覆蓋處理對(duì)于深層土壤溫度的影響效果隨著土壤深度的不斷增加逐漸減小。由此可知在秸稈覆蓋處理下某點(diǎn)的土壤溫度是由秸稈覆蓋量、土壤導(dǎo)熱特性與土壤深度相互作用的結(jié)果。(2)通過對(duì)于土壤溫度系數(shù)的定義計(jì)算分比較了不同地塊之間的土壤溫度差異系數(shù),發(fā)現(xiàn)裸地處理土壤溫度差異系數(shù)最大,而裸地淺層土壤溫度差異系數(shù)約是裸地深層土壤溫度差異系數(shù)的3倍。在秸稈覆蓋處理下,各個(gè)深度的土壤溫度差異系數(shù)均是5cm秸稈覆蓋處理最大,其次為15cm秸稈覆蓋處理,10cm秸稈覆蓋處理下土壤溫度差異系數(shù)最小。由此可知秸稈覆蓋量雖然以5cm厚度梯度增加,但是不同覆蓋處理各深度下土壤溫度差異系數(shù)卻并未隨著覆蓋厚度的梯度增加而增加,可見秸稈覆蓋厚度的單調(diào)遞增或遞減對(duì)于溫度的變化并非為單調(diào)趨勢(shì)。(3)秸稈覆蓋能夠延遲0~60cm土層內(nèi)液態(tài)含水率增加或減小的時(shí)間拐點(diǎn),隨著秸稈覆蓋厚度的增加其延遲效果越明顯,但土壤凍結(jié)期的延遲效果比凍土融化期明顯;秸稈覆蓋能夠阻礙凍土融化初期融雪水入滲、抑制凍土融化末期土壤水蒸發(fā),對(duì)于土壤墑情的增加具有非常重要的意義。隨著土壤深度的增加,各處理土壤液態(tài)含水率的極差Ka和變異系數(shù)Cv均呈現(xiàn)出減小趨勢(shì);當(dāng)土壤深度超過100cm時(shí),各處理土壤液態(tài)含水率變化甚微;當(dāng)秸稈覆蓋大于等于10cm時(shí),各深度土壤液態(tài)含水率的變化甚微。秸稈覆蓋可有效平抑凍融期0~60cm土層土壤液態(tài)含水率的變化幅度,且隨著深度的增加其平抑效果具有減弱趨勢(shì)。積雪融水和秸稈覆蓋的雙重作用可有效增加土壤墑情,但其增墑能力隨著土壤深度的增加而降低,不同秸稈覆蓋厚度對(duì)0~60cm土層的平均增墑能力由大到小排序依次為:15、10、5cm。
[Abstract]:Heilongjiang province is an important food production base in our country, because the climate in the northeast of China is cold and the water resource per capita is lower than the national level, the shortage of water resources seriously restricts the development of the industry and agriculture in our province. Especially in China, the agricultural cultivation mode is relatively backward, and the utilization rate of water resources is only 45%, which is backward in many developed countries, and the effective utilization of the existing land resources and water resources is of particular importance, and the water-saving irrigation can improve the agricultural single-production to become one of the most important problems of the national food security. in that cold zone of the north-eastern part of China, the change rule of soil moisture and temperature under the treatment of different straw in winter is analyzed based on the observation data of the field experiment in winter. The results obtained from the analysis of the test data are as follows: (1) the straw is covered as a medium which is an obstacle to the heat exchange between the soil and the atmosphere, and the heat is distributed to the atmosphere from the soil, and the heat in the atmosphere is transferred to the soil to have a certain blocking effect. However, due to the different direction of heat transfer under different temperature conditions, the effect of straw mulching on soil temperature is different, and the change trend of soil temperature is always lagging behind the change trend of atmospheric temperature. Because the surface soil is relatively close to the atmospheric contact, the change of the external environment has a significant effect on the surface soil. As the depth of the soil increases, the consumption of heat transfer and the specific gravity of the time are gradually changed, so the effect of different straw covering treatments on the deep soil temperature gradually decreases with the increasing of the depth of the soil. It can be seen that the soil temperature of a certain point under the straw mulching treatment is the result of the interaction between the straw mulching amount, the soil thermal conductivity and the soil depth. (2) Through the definition of the soil temperature coefficient, the soil temperature difference coefficient between the different plots is compared, and the difference coefficient of the soil temperature difference is found to be the largest, while the difference coefficient of the temperature difference of the bare ground layer is about 3 times that of the bare ground deep soil temperature difference coefficient. Under the straw mulching treatment, the soil temperature difference coefficient of each depth is the maximum of the 5cm straw mulching treatment, followed by the 15cm straw mulching treatment, and the soil temperature difference coefficient is the smallest under the 10cm straw mulching treatment. It can be seen that although the thickness gradient of the straw is increased with the thickness of 5cm, the difference coefficient of soil temperature is not increased with the increase of the gradient of the covering thickness, and the monotonicity of the covered thickness of the straw is not a monotone trend for the change of the temperature. (3) The time point of increasing or decreasing the water content of the soil in the 0-60cm soil layer can be delayed by the straw covering, and the more obvious the delay effect with the increase of the covering thickness of the straw, the delay effect of the soil freezing period is more obvious than the melting period of the frozen soil; The cover of the straw can prevent the infiltration of the snow and water during the initial period of the frozen soil and inhibit the evaporation of the soil water at the end of the melting of the frozen soil, which is of great significance to the increase of the soil moisture content. As the depth of the soil is increased, the range Ka and the coefficient of variation Cv of the liquid water content of each treatment soil show a decreasing trend; when the depth of the soil exceeds 100cm, the liquid water content of each treatment soil changes little; when the straw coverage is more than or equal to 10cm, There is little change in the water content of the soil in each depth. The change of the liquid water content of the soil in the 0-60cm soil layer can be effectively controlled by the straw mulching, and the effect of the improvement of the depth increases with the increase of the depth. The double action of the snow-melting water and the straw mulching can effectively increase the soil drought condition, but the increasing capacity of the soil is reduced with the increase of the depth of the soil, and the average increasing capacity of the different straw covering thickness on the 0-60cm soil layer is in the order of 15, 10 and 5 cm in sequence.
【學(xué)位授予單位】：東北農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：S152

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 薜宗讓，王盛霞，劉虎林，聶蘭生;旱地玉米免耕秸稈覆蓋量試驗(yàn)[J];山西農(nóng)業(yè)科學(xué);1994年03期

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本文編號(hào)：2411016