| 摘要: |
| 【目的】研究不同土地利用类型土壤水氮变化特征及其相关性，为滇中高原农田红壤土水肥流失和治理提供科学依据。【方法】通过2018年6—10月自然降水条件下标准径流小区的试验数据分析，对林地、园地、荒草地、坡耕地和裸地土壤水氮各指标进行测定，并分析其相关性，其中裸地作为对照。【结果】在土壤深度方向上，土壤含水率随土层深度的增加而增大；5种地类土壤全氮的量均值分别为1.67、0.76、0.70、0.52和0.67 g/kg。土壤硝态氮在0～100 cm土层平均量最高园地为13.39 mg/kg，最低裸地为5.13 mg/kg；林地、坡耕地、荒草地土壤铵态氮量随土壤深度先减少后增加。在时间上，土壤含水率呈波动性变化；土壤全氮量在6—10月平均值最大为园地（0.92 g/kg），最小为坡耕地（0.50 g/kg）；林地、荒草地、坡耕地土壤硝态氮量随时间延长逐渐减小；园地和裸地土壤铵态氮量随时间延长减少。土壤含水率和土壤铵态氮量与土层深度呈极显著相关关系（P<0.01），土壤硝态氮和土壤铵态氮与时间的相关系数分别为-0.440，P=0.028和-0.442，P=0.027，变化呈显著相关关系。【结论】滇中高原农田红壤土壤水分垂直运移规律为随土壤深度增加而增大，不同土地利用类型土壤氮素时空差异较大，土壤全氮的量与土壤深度和时间相关性不显著（P>0.05）。 |
| 关键词: 土地利用类型；土壤氮素；土壤含水率；滇中高原 |
| DOI：10.13522/j.cnki.ggps.20190126 |
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| Experimental study on water and nitrogen dynamics in soil under different land usages in central yunnan plateau |
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YANG Cuiping, TUO Yunfei, SHEN Fangyuan, MA Jimin, WU Yaozhong
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1. Ecology and Environment Department in Southwest Forestry University, Kunming 650224, China;2. Water Resources Bureau, Jinning District, Kunming 650607, China
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| Abstract: |
| 【Objective】Water and nitrogen dynamics in soil was modulated by land use and cropping, and this paper aims to investigate the change and correlation of soil water and nitrogen under different land use in attempts to provide guidance for water and fertilizer management in red loam farmland in central Yunnan plateau.【Method】 The experiment was conducted in plots with contrasting land use under natural precipitation from June to October in 2018. The land use we studied included forest, garden, barren grass, slopes, with bare soil serving as the control. In each plot, we measured the water and nitrogen in the soil.【Result】In all treatments, water content increased with soil depth, and the mean total soil nitrogen under forest, garden, barren grass, slopes and bare soil was 1.67, 0.76, 0.70, 0.52 and 0.67 g/kg, respectively. Garden had the highest Nitrate content, being 13.39mg/kg in the 0~100 cm soil. Bare soil stored least nitrogen at 5.13 mg/kg. Ammonium content decreased first and then increased along the soil depth in both the forest and slope. The highest average total nitrogen from June to October was 0.92 g/kg, found in garden, and the lowest was 0.50 g/kg, found in the slope. Nitrate in forest, grass and slope, as well as ammonium in garden and bare soils, have all been declining with time. Both soil moisture and ammonium were correlated with soil depth at significant level (P<0.01), and nitrate and ammonium were correlated with time with their correlation coefficient being -0.440 and -0.442, and P being 0.028 and 0.027, respectively.【Conclusion】Soil moisture in red load farmland in central Yunnan plateau increased with soil depth. The spatiotemporal difference in soil nitrogen between different land use was significant. Soil total nitrogen content was not correlated to soil depth and time at significant level (P>0.05). |
| Key words: types of land usage; soil nitrogen; soil water content; central Yunnan plateau |
