宾县黑土区耕地垄向干扰下土壤侵蚀特征研究

发布时间：2018-06-16 03:37

本文选题：耕地沟蚀 + 耕作垄向　；参考：《东北农业大学》2017年硕士论文

【摘要】：东北黑土区在长期高强度开垦连作下,侵蚀沟分割耕地地表现象严重,耕地质量下降、养分流失等问题凸显。在充分了解黑龙江省宾县耕地利用结构时空变化特征和耕地利用侵蚀程度特征的基础上,综合自然条件、侵蚀程度、耕作方式差异,挑选糖坊镇和三宝乡作为典型乡镇探究耕地垄向干扰下土壤侵蚀特征。首先,基于GIS和RS技术,采用全局空间自相关等方法,综合垄向、侵蚀沟、地形数据探究区域尺度下垄向分布及不同垄向耕地沟蚀与地形因子耦合规律。其次,综合统计学的模型方法,对两乡镇沟蚀对土壤中有机质、全氮、全磷和速效钾含量的影响及不同垄向耕作下沟蚀对各养分的影响及差异展开研究。结果表明:(1)1986~2000年,研究区宾县耕地增减均多分布在2~4°平缓地带,2000~2015年新增耕地在高坡度分布增加。1986~2000年耕地增减均多分布在低起伏地带,2000~2015年新增耕地及退耕耕地在高起伏分布均有增加。(2)1986~2015年,宾县17个乡镇中有11个乡镇耕地破碎指数增加,耕地整体呈破碎化态势。稳定耕地上沟蚀分布广泛、沟蚀密度相对动态耕地密度低。侵蚀沟的存在期长,是地形、降雨、耕作方式长期作用的结果,耕作垄向是长期潜在的人为侵蚀因子。(3)两个典型乡镇的沟蚀空间集聚程度不同,主导性垄向耕地内的侵蚀程度最高。垄向在耕地上的分布有很强的空间自相关性,不同的垄向空间分布是对地形条件的反馈体现,合理的垄向空间分布会起到降低沟蚀密度的作用。(4)除糖坊镇斜垄外,不同垄向耕地沟蚀密度随海拔的升高呈现先增大后减小的趋势。糖坊镇不同海拔级优势垄向规律性不强,三宝乡整体上任意海拔级斜垄耕作最优。坡度与坡长交互作用显著。两乡镇表现为“小坡度”+“小坡长”或“小坡度”+“大坡长”条件jk垄耕作最优,“大坡度”+“小坡长”或“大坡度”+“大坡长”条件斜垄耕作最优。糖坊镇和三宝乡在0~25 m地形起伏下分别是斜垄耕作和顺垄耕作最优。从耕地侵蚀数量角度,黑土区漫川漫岗地带斜垄耕作更具水土保持作用。(5)沟蚀对土壤养分含量影响较大,有机质和全氮含量较无侵蚀区分别减少33.43%和46.67%,速效钾与全磷含量变化不明显,在沟蚀区进行秸秆覆盖能够减少土壤养分流失。沟蚀在造成养分含量下降的同时,也影响了土壤的理化结构,降低了土壤中有机质和全氮含量之间的相关性。(6)两个典型乡镇横垄沟蚀、顺垄沟蚀及无沟蚀对照组土壤有机质和全氮含量大小均表现为无沟蚀区顺垄沟蚀jk垄沟蚀。从耕地侵蚀养分角度,无侵蚀区土壤养分含量最高,沟蚀区顺垄耕作较横垄耕作更具保肥意义。
[Abstract]:Under the long-term high intensity reclamation and continuous cropping in the black soil area of Northeast China, the phenomenon of erosion ditch dividing cultivated land surface is serious, the quality of cultivated land is declining, and the problems of nutrient loss are prominent. On the basis of fully understanding the temporal and spatial characteristics of cultivated land use structure and the characteristics of cultivated land erosion degree in Binxian County, Heilongjiang Province, the differences of natural conditions, erosion degree and tillage methods are considered. Select Tangfang Town and Sambao Township as typical towns to explore the characteristics of soil erosion under ridge disturbance. Firstly, based on GIS and RS technology, the global spatial autocorrelation method is used to study the distribution of ridge direction at regional scale and the coupling law between furrow erosion and topographic factors in different ridges by means of comprehensive ridge direction, erosion channel and topographic data. Secondly, the effects of furrow erosion on soil organic matter, total nitrogen, total phosphorus and available potassium in two villages and towns, and the effects and differences of furrow erosion on various nutrients under different ridge tillage were studied by comprehensive statistical model method. The results show that the first one is from 1986 to 2000. The increase and decrease of cultivated land in Binxian County were mostly distributed in the area of 2o 4 掳flat area from 2000 to 2015. The increase and decrease of cultivated land from 1986 to 2000 were mostly distributed in the low undulation area, and the distribution of new cultivated land from 2000 to 2015 and that of returning cultivated land increased from 1986 to 2015, respectively. In 17 villages and towns of Binxian county, 11 villages and towns increased the fragmentation index of cultivated land, and the whole cultivated land showed a trend of fragmentation. The distribution of trench erosion on stable cultivated land is widespread, and the density of trench erosion is lower than that of dynamic cultivated land. The existence of erosion ditch is the result of the long-term effect of topography, rainfall and tillage methods, and the furrow direction is the potential long-term human erosion factor. 3) the spatial accumulation degree of furrow erosion in two typical towns is different. The erosion of dominant ridges to cultivated land is the highest. The distribution of ridge direction on cultivated land has strong spatial autocorrelation. Different spatial distribution of ridge direction reflects the feedback of terrain conditions. Reasonable spatial distribution of ridge direction will play a role in reducing the density of furrow erosion. The furrow erosion density of different ridges increased first and then decreased with the increase of altitude. The dominant ridge direction of different elevation level in Tangfang town is not regular, and the slope ridge tillage at any elevation level is the best in Sanbao township as a whole. The interaction between slope and slope length is significant. In the two towns, the conditions of "small slope", "small slope length" or "small slope degree" and "large slope length" are the optimum conditions of ridge tillage, and "large slope" and "small slope length" or "big slope" and "big slope length" are the best conditions for slant ridge tillage. In Tangfang Town and Sambao Town, the slope ridge tillage and the shun ridge tillage were the best under the topographic fluctuation of 0 ~ 25 m, respectively. From the point of view of cultivated land erosion quantity, slanting ridge tillage has more soil and water conservation effect on soil nutrient content. The contents of organic matter and total nitrogen decreased 33.43% and 46.67%, respectively, and the contents of available potassium and total phosphorus did not change obviously. Straw mulching in gully erosion area could reduce soil nutrient loss. Furrow erosion not only caused the decrease of nutrient content, but also affected the physical and chemical structure of soil, and reduced the correlation between organic matter and total nitrogen content in soil. The content of organic matter and total nitrogen in soil of the control groups with and without furrow erosion showed that the soil organic matter and total nitrogen content in the control group were JK ridge erosion in no trench erosion area. From the point of view of cultivated land erosion nutrient, the soil nutrient content in no-erosion area was the highest, and furrow tillage was more significant than transverse ridge tillage.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S157.1

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