基于能值理论的开采沉陷地养分变化研究

应用能值理论,以能值作为度量工具,将土壤生态系统内流动和储存的各种不同种类的能量和物质转换成同一标准,开展矿区沉陷地土壤问题的研究。根据土壤养分能值的转换率,计算出土壤养分所具有的能值,分析沉陷地整治前后的土壤养分变化,并利用能值计算出土壤的养分信息熵,以揭示沉陷地土壤系统的演变规律。针对山东某矿区沉陷地的研究结果表明,随着沉陷深度的加大,土壤养分能值的变化轨迹呈V形,在开始阶段,养分能值随下沉深度加大而逐渐减少,达到某一极值后,土壤养分能值随沉陷深度加大而逐渐上升。从变化曲线上可以看出,养分能值在空间分布很不均匀;沉陷地表层土壤养分熵值较小,有序性较高,底部土层土壤养分熵值较大,有序性较差。不同时期泥浆泵复垦地0～20cm层土壤养分能值均低于对照正常农田,且随时间变化较大,总体趋于正常农田。20～40cm层养分能值高于或接近正常对照农田,而且变化幅度大于表层土壤。泥浆泵复垦地养分信息熵随着时间变化有较大的波动,总体上熵值在减小。研究结果对于沉陷土地的复垦与改良具有一定的指导意义。

Changes of Nutrient in Subsidence Land Based on Emergy

Soil problem in subsided land is one of focus issues to study. This paper applies emergy theory to study the soil problem in mining subsided land, which takes emergy value as a united measurement tool, translating various energy and substance moved and stored in soil ecological system to identical index. Firstly, the emergy value of soil nutrient is calculated by conversion rate of energy, accordingly, the change of soil nutrient in mining subsided land before and after reclamation is compared to that of the common farmland around the area. Then the information entropy of the soil nutrient is calculated by the emergy value in order to reveal the evolved rule of soil system within subsided land. The research on a mining area in Shandong province indicates that the change of emergy value of land nutrient shows a V shape along with the increasing subsided depth. At the subsidence beginning, nutrient emergy decreases with subsidence depth increasing, and when reaching a certain minimum, the trend turns up. The spatial distribution of emergy is uneven. The information entropy of soil nutrient at top layer of the subsided land is less with better order, while, more at the bottom layer with worse order. For the soil of reclaimed land in different periods with slurry pump, the nutrient emergy in 0~20 cm is lower than that in the control common farmland, but generally, the trend tends to the normal farmland, while, the nutrient emergy in 20~40 cm is over or near that of the common farmland, but the amplitude of change is greater than that of top soil. As a whole, the information entropy of nutrient energy at soil of reclaimed land with slurry pump decreases but largely fluctuated with time.