玉米秸秆焚烧对土壤理化性质和腐殖质组成的影响

Effect of Cron Straw Burning on Soil Physicochemical Property and Composition of Humus

以田间＂平铺式＂焚烧和＂成铺式＂2种玉米秸秆焚烧处理后的土壤为主要研究对象,采用田间焚烧试验与实验室热辐射焚烧模拟试验相结合的技术路线,研究秸秆燃烧时的燃烧特征及焚烧对土壤物理性质、有机碳含量及腐殖质组成的变化情况。结果表明,2种焚烧方式均使表层土壤含水量降低、硬度增高、土壤颜色发生明显改变,且成铺式焚烧对地表的热辐射温度要高于平铺式焚烧。2种焚烧方式均使0-2cm土层土壤有机碳含量降低,成铺式焚烧降低幅度明显大于平铺式焚烧。在热辐射焚烧试验中,有机碳含量随温度的升高呈逐渐降低趋势,且温度在200-360℃之间时,土壤有机碳含量下降幅度最大。随加热温度的升高,腐殖质提取量和提取率均呈先升高后降低的趋势,其最大腐殖质提取量及最大腐殖质提取率分别出现在200℃和240℃。2种焚烧方式处理下,土壤腐殖质提取率均有所升高,且成铺式焚烧方式下土壤腐殖质提取率已基本达到最大值。秸秆焚烧方式的不同对土壤腐殖质组成的影响也有不同程度的差异,但在各组成含量上均表现为成铺式焚烧显著低于平铺式焚烧,而成铺式焚烧在HA/FA上较平铺式焚烧有显著的升高。此外,热作用对结合态腐殖质的影响显著小于游离态腐殖质。

Currently in the Northeast region,there are ＂ Ping-pu burning＂ and ＂ Cheng-pu burning＂ of corn straw burning treatment.Thus,in this study the main research object is the field soil after two kinds of straw burning treatment,and chose field straw burning experiment combined with laboratory thermal radiation simulation experiment as technology route,the purpose was to discuss the characteristics of straw burning,and the changes of soil physical properties,organic carbon content and humus composition after burning straw.The results showed that both of two ways of straw burning make topsoil moisture content decreased,hardness increased,and significant changed in soil color,and the Cheng-pu burning was higher than Ping-pu burning with thermal radiation temperature on surface.Two straw burnings made soil organic carbon content lower just in 0-2cm topsoil,and the Cheng-pu burning was more significant.In the thermal radiation burning test,with increasing heat temperature,the soil organic carbon content trend to gradually decreasing,and in the temperature range of 200℃to 360℃,it has the largest falling range.With increasing heating temperature,the extraction amount and rate of humus tend to increased and then decreased,and the maximum amount of humus extract appeared at 200 ℃,the maximum extraction rate of humus appeared at240 ℃.The soil humus extraction rate was increased after two kinds of straw burning way,and in the Cheng-pu burning the extraction rate of humus had basically reached the maximum.With different ways of burning,there were different influence of humus composition,but the Cheng-pu burning significantly lower than the Ping-pu burning on each composition,and in the HA/FA ratio,the Cheng-pu burning was higher significantly.In addition,the influence of heat on combined humus was significantly less than the free humus.