不同覆盖条件下土壤水热时空分异差异性分析
发布时间：2019-01-18 19:01
【摘要】：黑龙江省是我国重要的粮食生产基地,由于地处我国东北部气候寒冷且人均水资源量低于全国水平,水资源的短缺严重制约了我省各项工业与农业的发展。尤其在我国农业耕作方式相对落后,水资源利用率仅为45%落后于很多发达国家,则有效的利用现有土地资源与水资源显得尤为重要,节水灌溉提高农业单产以成为国家粮食安全最重要的问题之一。本文针对于我国东北部寒冷地带,以冬季大田试验观测数据为根据对冬季不同秸秆覆盖处理下土壤水分与温度的变化规律进行分析,意图提出适宜的覆盖方案为春季春耕防止春旱做准备。通过对于试验数据的分析得到的研究结果如下:(1)秸秆覆盖作为一种阻碍土壤与大气热量交换的介质,对于热量由土壤之中散发至大气中、大气之中的热量传递到土壤之中均有一定的阻碍作用。但又由于在不同的气温条件下热量运移的方向不一致,使得秸秆覆盖对于土壤温度的调节作用不同,由此土壤温度的变化趋势总是滞后于大气温度的变化趋势。由于表层土壤与大气接触相对比较密切,所以外环境的变化对于表层土壤的影响效果显著。随着土壤深度不断的增加热量传递的消耗量与时间所占的比重逐渐变大,所以不同秸秆覆盖处理对于深层土壤温度的影响效果随着土壤深度的不断增加逐渐减小。由此可知在秸秆覆盖处理下某点的土壤温度是由秸秆覆盖量、土壤导热特性与土壤深度相互作用的结果。(2)通过对于土壤温度系数的定义计算分比较了不同地块之间的土壤温度差异系数,发现裸地处理土壤温度差异系数最大,而裸地浅层土壤温度差异系数约是裸地深层土壤温度差异系数的3倍。在秸秆覆盖处理下,各个深度的土壤温度差异系数均是5cm秸秆覆盖处理最大,其次为15cm秸秆覆盖处理,10cm秸秆覆盖处理下土壤温度差异系数最小。由此可知秸秆覆盖量虽然以5cm厚度梯度增加,但是不同覆盖处理各深度下土壤温度差异系数却并未随着覆盖厚度的梯度增加而增加,可见秸秆覆盖厚度的单调递增或递减对于温度的变化并非为单调趋势。(3)秸秆覆盖能够延迟0~60cm土层内液态含水率增加或减小的时间拐点,随着秸秆覆盖厚度的增加其延迟效果越明显,但土壤冻结期的延迟效果比冻土融化期明显;秸秆覆盖能够阻碍冻土融化初期融雪水入渗、抑制冻土融化末期土壤水蒸发,对于土壤墒情的增加具有非常重要的意义。随着土壤深度的增加,各处理土壤液态含水率的极差Ka和变异系数Cv均呈现出减小趋势;当土壤深度超过100cm时,各处理土壤液态含水率变化甚微;当秸秆覆盖大于等于10cm时,各深度土壤液态含水率的变化甚微。秸秆覆盖可有效平抑冻融期0~60cm土层土壤液态含水率的变化幅度,且随着深度的增加其平抑效果具有减弱趋势。积雪融水和秸秆覆盖的双重作用可有效增加土壤墒情,但其增墒能力随着土壤深度的增加而降低,不同秸秆覆盖厚度对0~60cm土层的平均增墒能力由大到小排序依次为: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.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S152
本文编号：2411016
[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.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S152
【参考文献】
相关期刊论文 前1条
1 薜宗让，王盛霞，刘虎林，聂兰生;旱地玉米免耕秸秆覆盖量试验[J];山西农业科学;1994年03期
，本文编号：2411016
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