| 张万涛,许明祥,李彬彬,吉静怡.复合地貌区农田土壤有机质空间变异特征及其影响因素[J].干旱地区农业研究,2021,39(1):175~181 |
| 复合地貌区农田土壤有机质空间变异特征及其影响因素 |
| Spatial variability and influencing factors of farmland soil organic matter in composite landforms |
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| DOI：10.7606/j.issn.1000-7601.2021.01.23 |
| 中文关键词: 土壤有机质 复合地貌区 空间变异 局部空间自相关 影响因素 随机森林算法 |
| 英文关键词:soil organic matter compound geomorphological area spatial variation local spatial autocorrelation influencing factors random forest algorithm |
| 基金项目:国家自然科学基金项目（41771318）；国家重点研发计划项目（2017YFC0506503） |
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| 中文摘要: |
| 以陕西省宝鸡市为例，运用地统计学方法，通过对比单一地貌和复合地貌下农田土壤有机质（SOM）变异特征，分析复合地貌区农田SOM空间变异及其影响因素。结果表明：研究区农田SOM含量为3~34.23 g·kg-1，平均值为18.23 g·kg-1，变异系数为25.73%，呈中等程度变异，不同地貌类型农田SOM变异系数表现为中海拔丘陵>低海拔丘陵>中海拔台地>中海拔平原> 低海拔平原>低海拔台地； SOM含量空间变异具有明显趋势性特征，各个方向存在各向异性，南北方向的空间变异性大于东西方向；研究区农田SOM含量具有显著局部空间自相关性，但各单一地貌类型下农田SOM含量局部空间自相关性不显著。研究区SOM含量块金值为41%，受结构因子影响更大。研究区农田SOM主要受经度、纬度、降水、温度、海拔等因子综合作用，其中纬度和海拔主要表现为直接作用，其他因子主要表现为间接作用。研究表明，复合地貌区农田SOM空间分布具有较强的空间自相关性，受地形、海拔等结构性因子的影响更大。 |
| 英文摘要: |
| Understanding the spatial variability of farmland soil organic matter（SOM）in composite landforms has important guiding value for farmland production and management. In this study, Baoji City, Shaanxi Province was used as the research area. By using geostatistical method, the spatial variability of farmland SOM and its influencing factors were analyzed by comparing the characteristics of SOM variability under single and composite landforms. The results showed that the farmland SOM content in the study area was between 3~34.23 g·kg-1, the average value was 18.23 g·kg-1, and the coefficient of variation was 25.73%, showing a moderate variation. The SOM variation coefficients of farmland with different landform types were: middle altitude hills > low altitude hills > middle altitude terraces > middle altitude plains > low altitude plains > low altitude platform. The spatial variability of SOM content had obvious trend characteristics, there was anisotropy in all directions, and the spatial variability in the north\|south direction was greater than that in the east\|west direction. The farmland SOM content in the study area had significant local spatial autocorrelation, but the local spatial autocorrelation of farmland SOM content under each single landform type was not significant. SOM content nugget value was 41%, which was more affected by structural factors. The farmland SOM in the study area was mainly affected by the combined effects of longitude, latitude, precipitation, temperature, altitude, and other factors. Among them, latitude and altitude mainly showed direct effects, and other factors mainly showed indirect effects. This study revealed that the spatial distribution of farmland SOM in the compound geomorphic area had a strong spatial autocorrelation and was more affected by structural factors such as terrain and altitude. |
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