不同低分子量有机酸对煤矸石养分释放的影响作用

摘要

为弄清低分子量有机酸在煤矸石风化物养分释放中的作用,通过在煤矸石风化物中添加不同种类、不同浓度的低分子量有机酸(苹果酸、柠檬酸、草酸),分析培养7 d、30 d及60 d后煤矸石pH值、碱解氮、速效磷、速效钾含量的变化及差异.结果表明:与对照相比,柠檬酸和苹果酸处理后的煤矸石pH值降低,而添加草酸对煤矸石的pH值具有提升的作用;苹果酸和柠檬酸对煤矸石碱解氮具有一定的释放作用,而草酸具有抑制作用;苹果酸和柠檬酸处理后的煤矸石速效钾含量呈现出下降趋势,草酸与之相反;在速效磷方面,供试有机酸均提高了煤矸石的速效磷含量.随着低分子量有机酸浓度的提高和培养时间的延长,柠檬酸和苹果酸处理后的煤矸石pH值基本表现为下降趋势,草酸则相反.随着实验周期的增加,煤矸石的碱解氮和速效磷含量都呈现出上升的规律,仅有速效钾呈现出下降的趋势.伴随浓度的升高,施入柠檬酸和苹果酸的煤矸石碱解氮组分基本保持下降的态势,草酸与之相反;三类酸处理后的煤矸石速效钾和速效磷含量并未随着有机酸浓度的升高表现出明显的规律性,说明有机酸浓度对煤矸石速效钾和速效磷组分的固定和释放影响不大.%In order to understand the active regularity of low molecular weight organic acids on coal gangue nutrient,dif-ferent kinds and different concentrations of low molecular weight organic acid ( malic acid,citric acid,oxalic acid) are added to the unweathered coal gangue,to analyze the changes and differences of pH,available nitrogen,available phosphorus and availa-ble potassium after 7 d,30 d,60 d. The result shows:compared with the control,adding citric acid and malic acid can reduce pH value of coal gangue,while adding oxalic acid can enhance the pH value of coal gangue;malic acid and citric acid have a certain release effect on the available nitrogen of coal gangue,but oxalic acid has inhibitory effect;After the treatment of malic acid and citric acid,the content of available K of gangue decreased,oxalic acid was opposite. In the aspect of available phos-phorus,organic acids all increased the content of available phosphorus in coal gangue. With the increase of the concentration of low molecular weight organic acids and the prolongation of culture time,the pH value of the coal gangue treated with citric acid and malic acid basically decreased,while oxalic acid was opposite. With the increase of experimental period,the content of a-vailable nitrogen and available phosphorus of coal gangue showed an upward trend,but only the available potassium showed a downward trend. Along with the increasing concentration of low molecular weight organic acids,application of citric acid and malic acid makes the available nitrogen content of coal gangue is basically a downward trend. Adding citric acid and malic acid makes the available nitrogen content of coal gangue is basically in decline,oxalic acid showed an opposite trend. Coal gangue available potassium and available phosphorus content of organic acid concentration increased with no obvious regularity,it shows a little effect of fixation and release of organic acid concentration on coal gangue available potassium and phosphorus fractions.