鄂尔多斯黄土丘陵区耕地围封后土壤性质变化的研究
发布时间：2018-07-25 10:30
【摘要】：黄土丘陵区生态环境脆弱,导致水土流失、土地沙化、干旱和洪涝灾害,其特殊的地理位置易风蚀,不仅对当地的经济发展、生态安全、人民生活造成影响,同时也对下游广大平原地区构成了严重威胁。然而,对于生态环境的改善势在必行,退耕还林还草是治理黄土高原水土流失的根本措施。退耕还林还草项目实施后导致土壤容重、土壤粘结力、土壤养分等土壤理化性质发生改变,为土壤修复提供理论依据,对于黄土高原水土流失综合治理意义重大。本文通过野外调查、资料收集和采样分析,运用地统计方法对黄土丘陵区土壤理化性质的变化规律进行研究,对比研究了耕地区与围封区(退耕区)的土壤理化性质及变化趋势,具体分析各土壤理化性质的差异,以土壤下垫面的改变为前提,总结出土壤性质的变化规律。得出如下结论:(1)围封区的土壤含水量比耕地区增加了0.6%,由于围封区地表植被覆盖好,这不仅使降雨后的径流减少,而且土壤表面的水分蒸发也减少了,耕地恰好相反。另外还可能是因为围封区主要为草本植物,其根系埋藏相对较深,从而对土壤下层的水分吸收较好,使得围封区表面的土壤水分较多。(2)耕地区的土壤容重比围封区增加了0.01g/cm3,其土壤孔隙度增加了1%。由于围封区的植物数量较耕地区多,使得草根在土壤的穿插过程中破坏了土壤颗粒组成,土壤孔隙度增加的同时土壤容重减少了。另外,草本植物的凋落物在土壤表层集聚,容易使凋落物分解腐化,最后形成了土壤有机质,然而降低了土壤容重。其次耕地区由于受到人为活动的影响,使得耕作土壤紧实孔隙少,所以土壤容重比较高。(3)耕地区土壤有机质含量的平均值为9.65g/kg,围封区土壤有机质含量的平均值为10.2g/kg,围封区的土壤有机质含量比耕地区高5.7%。与围封区相比较耕地区的土壤有机质偏低,由于在耕作土壤中有机质缺少了物理保护,另外土壤温度的上升也使得有机质含量降低,耕地土壤与有机残体的混合增加了微生物的活性,从而也增加了其分解速度。(4)耕地区土壤全氮含量的平均值为0.32g/kg,围封区的土壤全氮含量平均值为0.29g/kg,耕地区土壤全氮含量比围封区高10.34%。可能土壤全氮含量与土壤类型有关,样地的土壤为栗钙土,水土流失严重,使得土壤贫瘠,各样地有机质含量都很低,故全氮含量偏低。随着耕地退化程度的加剧,土壤全氮含量迅速下降。(5)耕地区土壤全磷含量的平均值为0.52g/kg,围封区土壤全磷含量的平均值为0.42g/kg,耕地区的土壤全磷含量比围封区高23.8%。围封区与耕种区的土壤全磷含量都是在第二层出现了递减,这可能是因为植物(作物)根系在5~10cm土层对磷的吸收较好有关。(6)围封区土壤全钾含量的平均值为3.43g/kg,耕地区土壤全钾含量的平均值为3.23g/kg,围封区的土壤全钾含量比耕地区高6.19%。总体来看,围封区土壤全钾含量呈上升趋势,耕地区土壤全钾含量呈递减趋势,这可能与有机质分布急剧减少以及最初土壤母质、成土作用一致有关。(7)耕地区土壤速效氮含量的平均值为0.12mg/kg,围封区土壤速效氮含量的平均值为0.04mg/kg。耕地区的土壤速效氮含量高于围封区,这说明耕地区土壤氮素供应潜力要好于围封区。(8)围封区土壤速效磷含量的平均值为10.28mg/kg,耕地区土壤速效磷含量的平均值为65.51mg/kg。由此可知,耕地区的土壤速效磷含量高于围封区,这可能与耕地区实施了磷肥有关。然而植被在土壤中生根发芽,其根系会吸收土壤中的养分;土壤中发生了淋溶现象,会使部分营养成分淋湿;及其土壤中的枯枝落叶,这些因素都会对土壤的速效磷含量产生影响。(9)耕地区土壤速效钾含量的平均值为13.02mg/kg,围封区土壤速效钾含量的平均值为21.17mg/kg,围封区的土壤速效钾含量比耕地区高62.6%。耕地区土壤速效钾含量偏低,因为土壤速效钾主要以植物凋落物的分解来补给土壤中的速效钾含量,耕地区的植被稀少,从而造成土壤速效钾含量偏低。
[Abstract]:The ecological environment of the loess hilly area is fragile, which leads to soil erosion, land desertification, drought and flood, and its special geographical location is easy to wind erosion. It not only affects the local economic development, ecological security, people's lives, but also poses a severe threat to the lower reaches of the plain area. However, it is imperative to improve the ecological environment. Returning farmland to forest and grass is the fundamental measure to control soil erosion in the Loess Plateau. After the implementation of the project of returning farmland to forest and grass, the soil physical and chemical properties, such as soil bulk density, soil cohesive force, soil nutrient and so on, provide theoretical basis for soil remediation, which is of great significance for the comprehensive treatment of soil and water loss in the Loess Plateau. The variation of soil physical and chemical properties in the loess hilly region was studied by collecting and sampling analysis, and the soil physical and chemical properties of soil in the hilly loess hilly region were studied. The physical and chemical properties and change trends of soil in cultivated area and enclosed area were compared, and the differences of physical and chemical properties of soil were analyzed. The change of soil underlying surface was the premise, and the change of soil properties was summarized. The following conclusions are drawn as follows: (1) the soil moisture content in the enclosed area is increased by 0.6% than that in the cultivated area, because the cover of the surface vegetation in the enclosed area is good, which not only reduces the runoff after the rainfall, but also reduces the water evaporation on the soil surface, and the cultivated land is just the opposite. The soil moisture absorption of the lower soil layer is better, which makes the soil moisture in the enclosed area more soil moisture. (2) the soil bulk density of the cultivated area is increased by 0.01g/cm3, and the soil porosity increases by 1%. because the number of plants in the enclosed area is more than that in the ploughed area, which makes the grass root destroy the soil particle composition during the soil interspersing process. The soil bulk density decreased while the soil porosity increased. In addition, the litter of herbaceous plants gathered on the surface of the soil, which could easily decompose and decompose the litter, finally formed the soil organic matter, but reduced the soil bulk density. Secondly, the tillage area was affected by human activities, making the soil tight in the cultivated soil less pore, so the soil bulk density ratio was compared. (3) the average value of soil organic matter content in cultivated area is 9.65g/kg, the average value of soil organic matter content in enclosed area is 10.2g/kg. The organic matter content of soil organic matter in enclosure area is higher than that in cultivated area 5.7%. and enclosure area. The increase of organic matter reduced the content of organic matter, the mixing of soil and organic residue increased the activity of microorganism and increased its decomposition rate. (4) the average value of total nitrogen content in the cultivated area was 0.32g/kg, the average soil total nitrogen content in the enclosed area was 0.29g/kg, and the total nitrogen content in the cultivated area was 10.34%. higher than that in the enclosed area. The total nitrogen content of the soil is related to the soil type, the soil of the sample land is chestnut soil, the soil erosion is serious, the soil is poor and the content of the organic matter is very low, so the total nitrogen content is low. (5) the total nitrogen content of the soil decreases rapidly. (5) the average value of the total phosphorus content of the soil in the cultivated area is 0.52g/kg. The average phosphorus content was 0.42g/kg. The total P content of soil in the cultivated area was higher than that in the enclosure area. The total phosphorus content of the soil in the 23.8%. enclosure and the cultivated area decreased progressively in the second layer. This may be due to the better absorption of phosphorus in the roots of the plant (crop) in the 5~10cm soil layer. (6) the average value of the total potassium content in the enclosed area was 3.43g/kg. The average soil total potassium content in the area is 3.23g/kg, and the total K content in the enclosed area is higher than that of the cultivated area. The total K content of soil in the enclosed area is rising, and the total potassium content of soil in the cultivated area is decreasing, which may be related to the sharp decrease in the distribution of organic matter and the consistency of soil parent material and soil formation. (7) ploughing area. The average soil available nitrogen content was 0.12mg/kg. The average soil available nitrogen content in the enclosed area was higher than that in the enclosure area, which indicated that the soil nitrogen supply potential in the cultivated area was better than that in the enclosure area. (8) the average soil available phosphorus content in the enclosed area was 10.28mg/kg, and the available phosphorus in the cultivated area was contained in the soil. The average value of the amount is 65.51mg/kg., so the content of available P in the cultivated area is higher than that in the enclosed area, which may be related to the implementation of the phosphate fertilizer in the cultivated area. However, the roots and roots of the soil will absorb the nutrients in the soil, and the leaching phenomenon occurs in the soil, which will make some nutrients wet, and the litter in the soil. These factors will affect the content of available phosphorus in the soil. (9) the average value of soil available potassium in the cultivated area is 13.02mg/kg, the average value of soil available potassium in the enclosed area is 21.17mg/kg. The content of available K in the enclosed area is lower than that in the cultivated area, which is lower than that in the cultivated area, because the available potassium in the soil is mainly in the area of 62.6%.. The decomposition of plant litter to supply the available potassium in the soil and the sparse vegetation in the farming area resulted in a low content of available potassium in the soil.
【学位授予单位】：内蒙古师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S151.9
[Abstract]:The ecological environment of the loess hilly area is fragile, which leads to soil erosion, land desertification, drought and flood, and its special geographical location is easy to wind erosion. It not only affects the local economic development, ecological security, people's lives, but also poses a severe threat to the lower reaches of the plain area. However, it is imperative to improve the ecological environment. Returning farmland to forest and grass is the fundamental measure to control soil erosion in the Loess Plateau. After the implementation of the project of returning farmland to forest and grass, the soil physical and chemical properties, such as soil bulk density, soil cohesive force, soil nutrient and so on, provide theoretical basis for soil remediation, which is of great significance for the comprehensive treatment of soil and water loss in the Loess Plateau. The variation of soil physical and chemical properties in the loess hilly region was studied by collecting and sampling analysis, and the soil physical and chemical properties of soil in the hilly loess hilly region were studied. The physical and chemical properties and change trends of soil in cultivated area and enclosed area were compared, and the differences of physical and chemical properties of soil were analyzed. The change of soil underlying surface was the premise, and the change of soil properties was summarized. The following conclusions are drawn as follows: (1) the soil moisture content in the enclosed area is increased by 0.6% than that in the cultivated area, because the cover of the surface vegetation in the enclosed area is good, which not only reduces the runoff after the rainfall, but also reduces the water evaporation on the soil surface, and the cultivated land is just the opposite. The soil moisture absorption of the lower soil layer is better, which makes the soil moisture in the enclosed area more soil moisture. (2) the soil bulk density of the cultivated area is increased by 0.01g/cm3, and the soil porosity increases by 1%. because the number of plants in the enclosed area is more than that in the ploughed area, which makes the grass root destroy the soil particle composition during the soil interspersing process. The soil bulk density decreased while the soil porosity increased. In addition, the litter of herbaceous plants gathered on the surface of the soil, which could easily decompose and decompose the litter, finally formed the soil organic matter, but reduced the soil bulk density. Secondly, the tillage area was affected by human activities, making the soil tight in the cultivated soil less pore, so the soil bulk density ratio was compared. (3) the average value of soil organic matter content in cultivated area is 9.65g/kg, the average value of soil organic matter content in enclosed area is 10.2g/kg. The organic matter content of soil organic matter in enclosure area is higher than that in cultivated area 5.7%. and enclosure area. The increase of organic matter reduced the content of organic matter, the mixing of soil and organic residue increased the activity of microorganism and increased its decomposition rate. (4) the average value of total nitrogen content in the cultivated area was 0.32g/kg, the average soil total nitrogen content in the enclosed area was 0.29g/kg, and the total nitrogen content in the cultivated area was 10.34%. higher than that in the enclosed area. The total nitrogen content of the soil is related to the soil type, the soil of the sample land is chestnut soil, the soil erosion is serious, the soil is poor and the content of the organic matter is very low, so the total nitrogen content is low. (5) the total nitrogen content of the soil decreases rapidly. (5) the average value of the total phosphorus content of the soil in the cultivated area is 0.52g/kg. The average phosphorus content was 0.42g/kg. The total P content of soil in the cultivated area was higher than that in the enclosure area. The total phosphorus content of the soil in the 23.8%. enclosure and the cultivated area decreased progressively in the second layer. This may be due to the better absorption of phosphorus in the roots of the plant (crop) in the 5~10cm soil layer. (6) the average value of the total potassium content in the enclosed area was 3.43g/kg. The average soil total potassium content in the area is 3.23g/kg, and the total K content in the enclosed area is higher than that of the cultivated area. The total K content of soil in the enclosed area is rising, and the total potassium content of soil in the cultivated area is decreasing, which may be related to the sharp decrease in the distribution of organic matter and the consistency of soil parent material and soil formation. (7) ploughing area. The average soil available nitrogen content was 0.12mg/kg. The average soil available nitrogen content in the enclosed area was higher than that in the enclosure area, which indicated that the soil nitrogen supply potential in the cultivated area was better than that in the enclosure area. (8) the average soil available phosphorus content in the enclosed area was 10.28mg/kg, and the available phosphorus in the cultivated area was contained in the soil. The average value of the amount is 65.51mg/kg., so the content of available P in the cultivated area is higher than that in the enclosed area, which may be related to the implementation of the phosphate fertilizer in the cultivated area. However, the roots and roots of the soil will absorb the nutrients in the soil, and the leaching phenomenon occurs in the soil, which will make some nutrients wet, and the litter in the soil. These factors will affect the content of available phosphorus in the soil. (9) the average value of soil available potassium in the cultivated area is 13.02mg/kg, the average value of soil available potassium in the enclosed area is 21.17mg/kg. The content of available K in the enclosed area is lower than that in the cultivated area, which is lower than that in the cultivated area, because the available potassium in the soil is mainly in the area of 62.6%.. The decomposition of plant litter to supply the available potassium in the soil and the sparse vegetation in the farming area resulted in a low content of available potassium in the soil.
【学位授予单位】：内蒙古师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S151.9
【参考文献】
相关期刊论文 前10条
1 王颖;崔向新;金娟;史万林;张琪;孙青;;围栏封育对典型草原土壤特征的影响[J];北方园艺;2015年10期
2 李学斌;陈林;樊瑞霞;吴秀玲;谢应忠;;围封条件下荒漠草原4种典型植物群落枯落物输入对土壤理化性质的影响[J];浙江大学学报(农业与生命科学版);2015年01期
3 董莉丽;冯珍;刘晶晶;;陕西省退耕还林对土壤粒径分布体积分形特征的影响[J];科学技术与工程;2014年25期
4 李军保;曹庆喜;吐尔逊娜依·热依木江;朱进忠;;围封对伊犁河谷春秋草场土壤理化性质及酶活性的影响[J];中国草地学报;2014年01期
5 张国芬;姚延h，
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