施氮对荆条灌丛土壤养分空间分布的影响

发布时间：2018-05-28 18:24

本文选题：荆条 + 施氮　；参考：《河南农业大学》2015年硕士论文

【摘要】：大气氮沉降对生态系统的影响是现代生态学关注的焦点问题。针对干旱半干旱地区的太行山低山丘陵地区,采用施氮肥模拟氮沉降来了解其对荆条灌丛土壤养分含量变化特征及其空间变异性的影响,以期为太行山地区植被恢复提供理论依据。在太行山低山丘陵区选取5个荆条样本进行不同的施氮处理、采样分析并通过运用传统统计分析方法及地统计学方法,对样本土壤的pH值、有机质、全氮和速效磷含量分析,主要研究结果如下:(1)施氮前不同施氮处理荆条样本的土壤pH值均值为7.2723。土壤有机质、全氮和速效磷的均值分别为13.0184g/kg、0.8390g/kg和8.0657mg/kg,施氮后30天,土壤有机质、全氮和速效磷的均值分别为12.0511g/kg、0.8593g/kg和20.4264mg/kg,施氮后60天,土壤有机质、全氮和速效磷的均值分别为13.8526g/kg、0.9721g/kg和10.0939mg/kg,在养分分级上均为低等水平。在变异程度上来说,pH值为弱变异,有机质和全氮为中等程度变异,速效磷为强变异。(2)整体上来说,土壤养分的相关性为:pH与有机质、全氮存在极显著负相关关系,全氮与有机质存在极显著正相关,除施氮后60天土壤速效磷与pH值存在负相关,速效磷与pH、有机质及全氮不存在相关性。(3)施氮前后各施氮处理土壤有机质、全氮和速效磷含量的C0值均较小;大部分C0/(C+C0)25%;有机质变程的变化范围为40.4~361.65 m,全氮的变程范围为40.4~491.56m,速效磷的变化范围为51.3~824.4m;模拟函数的残差值都较小,说明半方差函数的拟合效果都较好。(4)荆条灌丛养分空间变化为:在表层(0-5cm),施氮前后不同处理的荆条灌丛土壤有机质、全氮大部分表现为随距离的增加而先升高后降低,拐点出现在60-90cm处;速效磷的变化趋势大体上随距离增加而降低;在中层(5-10cm)与下层(10-20cm)处,荆条灌丛土壤有机质和全氮含量随水平距离的变化不大;土壤速效磷含量没有明显的规律性。(5)施氮前后不同施氮处理的荆条灌丛样本的土壤有机质、全氮、速效磷含量都表现出冠幅内高于冠幅外;施氮后部分高施氮处理灌丛的富集率有着显著的上升,表明施氮能够促进荆条土壤中营养的富集。施氮后,土壤中养分含量不同程度的高于施氮前水平,表明施氮有助于提高土壤养分含量。(6)在垂直方向上,施氮前后不同施氮处理灌丛大部分土壤养分含量都随距离的加深而降低,即0-5cm5-10cm10-20cm。
[Abstract]:The effect of atmospheric nitrogen deposition on ecosystem is the focus of modern ecology. In this paper, nitrogen fertilizer was applied to simulate nitrogen deposition in Taihang Mountain low mountain hilly area in arid and semi-arid area to understand the effect of nitrogen fertilizer application on soil nutrient content and spatial variability. In order to provide theoretical basis for vegetation restoration in Taihang Mountain area. Five samples of wattle were selected in the hilly area of Taihang Mountain for different nitrogen application. The soil pH, organic matter, total nitrogen and available phosphorus were analyzed by traditional statistical analysis and geostatistical method. The main results were as follows: (1) the average soil pH value of the samples treated with different nitrogen application was 7.2723. The mean values of soil organic matter, total nitrogen and available phosphorus were 13.01844 g / kg 0.839 g / kg and 8.0657 mg / kg, respectively. The mean values of soil organic matter, total nitrogen and available phosphorus were 12.0511 g / kg and 20.4264 mg / kg, respectively, and 60 days after application of nitrogen, soil organic matter. The mean values of total nitrogen and available phosphorus were 13.8526 g / kg 0.9721 g / kg and 10.0939 mg / kg, respectively. On the whole, the correlation of soil nutrients was: the correlation of pH value and organic matter was weak, that of organic matter and total nitrogen was moderate, and that of available phosphorus was strong. (2) on the whole, the correlation between soil nutrient and organic matter was that there was a very significant negative correlation between soil nutrient and organic matter, and there was a very significant negative correlation between total nitrogen and total nitrogen. There was a significant positive correlation between total nitrogen and organic matter. There was a negative correlation between available phosphorus and pH value at 60 days after application of nitrogen, and there was no correlation between available phosphorus and pH, and there was no correlation between organic matter and total nitrogen. The C _ 0 values of total nitrogen and available phosphorus contents are small; most C _ 0 / C _ 0 C _ (0) and C _ (0) C _ (25); the range of variation range of organic matter is 40.4 ~ 361.65 m; the range of total nitrogen variation is 40.4 ~ 491.56 m, and the range of available phosphorus is 51.3 ~ 824.4 m; the residual value of simulation function is small. The results showed that the fitting effect of semi-variance function was better. 4) the spatial change of nutrient in the thicket was: 0 ~ 5 cm ~ (-1) in the surface layer, soil organic matter of different treatments before and after application of nitrogen, most of the total nitrogen was increased first and then decreased with the increase of distance. The change trend of available phosphorus decreased with the increase of distance, while in the middle layer (5-10 cm) and the lower layer (10-20 cm), the soil organic matter and total nitrogen content of the wattle shrub changed little with the horizontal distance. There was no obvious regularity of available phosphorus content in soil. 5) soil organic matter, total nitrogen and available phosphorus contents in different nitrogen treatments were higher than those outside crown before and after N application. The enrichment rate of some high nitrogen treatments increased significantly after nitrogen application, which indicated that nitrogen application could promote the enrichment of nutrients in the soil. After nitrogen application, the nutrient content in soil was higher than that before nitrogen application, which indicated that nitrogen application could increase soil nutrient content in the vertical direction. The nutrient content of most of the soil decreased with the increase of distance before and after the application of nitrogen, i.e. 0-5cm5-10cm10-20cm.
【学位授予单位】：河南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S158

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