黄河三角洲不同土地利用方式土壤碳库结构和养分特性

发布时间：2018-03-19 05:30

本文选题：黄河三角洲　切入点：土地利用方式　出处：《山东农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：以黄河三角洲东营市河口区3种典型土地利用方式(耕地、草地和林地)为研究对象,采用野外调查取样和室内实验分析相结合的方法,研究不同土地利用方式对土壤基本理化特性(含水量、容重、孔隙度、颗粒组分、团粒结构、p H、电导率)、土壤养分(全氮、硝铵态氮、速效磷、速效钾)、土壤有机碳库(总有机碳、易氧化有机碳、微生物量碳、ROC/SOC、MBC/SOC、碳库管理指数)的影响,为黄河三角洲河口区盐碱地合理利用和改良提供参考。主要研究结果如下:1、不同土地利用方式对土壤基本理化特性具有显著影响。各土层含水量在3种不同土地利用方式间均表现为耕地草地林地;研究区样地土壤容重和孔隙度受土地利用方式影响不明显,仅10~20 cm层草地与耕地和林地间表现为差异显著(p0.05);各土层不同土地利用方式土壤砂粒、粉粒、黏粒含量均表现为显著差异:0~20 cm各层土壤黏粒和粉粒含量均为草地耕地林地,20~50 cm土层粉粒和黏粒含量最少的均为耕地,其含量均在10%以下;研究样区土壤团聚体以非水稳性团聚体为主,草地的土壤团粒结构数量和稳定性优于耕地和林地。干筛法下土壤团聚体的平均重量直径(MWD)和几何平均直径(GMD)表现为草地(2.75 mm,1.96 mm)耕地(1.53 mm,0.73 mm)林地(1.04 mm,0.55 mm),且差异显著(p0.05);土壤p H、电导率在同一时期相同土层3种不同土地利用方式之间均差异显著(p0.05)。2、不同土地利用方式对土壤养分特性具有显著影响。土壤全氮含量在不同时期表现规律不同:春季除5~20 cm层,其余三层均为草地含量最高(最大值达1.63 mg·g-1),秋季5~50 cm层全氮含量最小值均出现在林地;硝态氮含量在秋季20~50 cm层林地略高于耕地外,两个季节各土层表现出相同规律:耕地林地草地;土壤铵态氮含量在两个时期差别较大,其中耕地0~5 cm层表现极为明显(春季铵态氮含量是秋季的6.8倍),秋季采样同土层耕地铵态氮含量显著低于草地和林地。草地土壤速效钾含量在春季各土层均显著高于耕地和林地,速效磷含量也均为草地最高;秋季土壤速效钾含量除0~10 cm外其他3层表现规律一致为林地草地耕地,耕地土壤速效磷含量在5~50 cm土层均显著高于草地和林地含量。3、不同土地利用方式对土壤有机碳、易氧化有机碳、微生物量碳含量均有显著影响。SOC在春季除0~5 cm层外均表现为草地耕地林地,秋季则为耕地草地林地;土壤ROC、MBC在两个时期不同土层表现规律不同,这与不同土地利用方式间土壤pH、电导率及土壤生物差异较大具有显著关系;各土层土壤ROC/SOC值均为林地显著高于耕地和草地且变化规律相同:林地草地耕地,MBC/SOC在各土层的最高值也都出现在林地;土壤碳库管理指数在不同土地利用方式样地间均表现为耕地最低,10~30 cm层草地高于槐树林地,总体上以苜蓿种植对盐碱地土壤改良效果显著。
[Abstract]:Taking three typical land use patterns (cultivated land, grassland and woodland) in Dongying City, Yellow River Delta as the research object, the method of field investigation and indoor experimental analysis was used. The basic physical and chemical properties (water content, bulk density, porosity, particle composition, aggregate structure, electrical conductivity), soil nutrients (total nitrogen, ammonium nitrate nitrogen, available phosphorus) of different land use patterns were studied. The effects of available potassium, soil organic carbon (total organic carbon, easily oxidized organic carbon, microbial biomass carbon, MBC / SOC, carbon pool management index), The main results are as follows: 1. The main results are as follows: 1. Different land use patterns have significant influence on the basic physical and chemical properties of soil. The patterns of utilization were cultivated land, grassland and woodland. The soil bulk density and porosity were not affected by the land use pattern, but there was significant difference between the grassland at 10 ~ 20 cm level and the cultivated land and forest land, and the soil sand and silt in different land use patterns in different soil layers, the soil density and porosity in the study area were not significantly affected by the land use pattern, but the difference was significant between the grassland and the cultivated land and forest land. The content of clay and silt in each layer of 20 cm soil layer were significantly different. The content of clay and silt in the soil layer of 20 ~ 50cm of grassland, woodland and woodland was the least in cultivated land, and the content of clay was less than 10%. The soil aggregates in the sample area were mainly non-water-stable aggregates. The average weight diameter (MWD) and geometric mean diameter (GMDD) of soil aggregates under dry sieve method were 2.75 mm / 1.96 mm) and 1.53 mm / 0.73 mm) respectively, and the difference was significant. Soil pH and electrical conductivity were significantly different among three different land use patterns in the same soil layer in the same period. Different land use patterns had a significant effect on soil nutrient characteristics. The total nitrogen content of soil was on the surface of different periods. The present law is different: in spring, except 5cm layer, The other three layers were the highest in grassland content (the maximum value was 1.63 mg 路g -1), the minimum of total nitrogen content in 5 ~ 50 cm layer appeared in the forest land in autumn, the nitrate nitrogen content in 20 ~ 50 cm layer in autumn was slightly higher than that outside the cultivated land. The soil layers of the two seasons showed the same regularity: cultivated land, woodland and grassland, and the content of ammonium nitrogen in the soil varied greatly in the two periods. The content of ammonium nitrogen was 6.8 times higher in spring than that in autumn. The content of ammonium nitrogen in the same soil layer in autumn was significantly lower than that in grassland and woodland. The available potassium content of soil in spring was significant in all soil layers. Higher than arable land and woodland, The available P content was also the highest in grassland, and the other three layers of soil available potassium content except 0 ~ 10 cm in autumn showed the same pattern as woodland and grassland cultivated land. The soil available phosphorus content of cultivated land was significantly higher than that of grassland and woodland in the soil layer of 5 ~ 50 cm, and the soil organic carbon was easily oxidized by different land use methods. Soil microbial biomass carbon content was significantly affected. SOC in spring, except 0 ~ 5 cm layer, showed as grassland and forest land, but in autumn, it was cultivated and grassland forest land, and soil ROCN MBC showed different regularity in different soil layers in the two periods. There was a significant relationship between soil pH, electrical conductivity and soil biological diversity among different land use patterns. The ROC/SOC value of each soil layer was significantly higher than that of cultivated land and grassland, and the law of change was the same: the highest value of MBC / SOC in each soil layer was also found in forest land. The soil carbon pool management index was higher than that of Sophora acacia forest in the lowest 1030 cm layer of cultivated land in different land use patterns, and the effect of alfalfa planting on soil improvement in saline-alkali land was significant.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S151.9

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