土地利用与裂缝对采煤沉陷土壤养分的影响

Impacts of land-use and ground fissure on soil nutrients in coal-mining subsidence landscapes

为更好地理解矿区土壤退化机理,选择焦作采煤沉陷区4种代表性土壤景观即有裂缝耕地、无裂缝耕地、有裂缝林地、无裂缝林地,评价土地利用与裂缝对沉陷土壤养分的影响。沉陷区耕地与林地2种利用方式中土壤有机碳(SOC)、全氮(TN)、全磷(TP)含量差异不显著(P>0.05),但裂缝有无对这3个养分参数影响显著(P<0.05);土地利用方式(耕地、林地)与裂缝因素(裂缝有无)之间的交互作用对SOC含量影响显著(P<0.05)。沉陷区SOC,TN,TP含量均表现为:无裂缝的林地与耕地>有裂缝的林地与耕地(P<0.05)。与对照区相比,4种景观的SOC含量均显著下降(P<0.05),TN,TP仅在有裂缝的耕地与林地显著降低(P<0.05)。研究结果表明,裂缝加剧了沉陷区耕地与林地的土壤C,N,P库损失,尤其是C库损失。在有裂缝情况下,沉陷耕地-林地转变降低土壤C库损失,但在无裂缝情况下,该转变加剧土壤C库损失。

In ovder to fully understand of land degradation in mining areas,four representative soil landscapewere selected from mining subsidence areas of Jiaozuo mine, including cultivated lands with fissures, cultivated lands without fissure, woodlands with fissures, and woodlands without fissure. Soil sampling and determination of organic carbon （SOC） , total nitrogen （TN） and phosphorus （TP） were carried out. There was nsignificant difference in soil organic carbon （SOC） , total nitrogen （TN） and phosphorus （TP） contents between cultivated lands and woodlands （P 〈0. 05） , whereas the three nutrients were significantly affected bfissure factor （i. e. fissure and no fissure） （ P 〉 0. 05） . The apparent interactions of land-use （i. e. cultivated land and woodland） and fissure factor on SOC were also found in subsidence soil landscapes （ P 〈 0. 05）.The SOC , TN and TP contents were higher in woodlands and cultivated lands without fissure than those inwoodlands and cultivated lands with fissure （P 〈0. 05） . Compared with the control field, i. e. a non-subsid-ence cropland nearby these subsidence landscapes, the four soil landscapes showed significantly lower SOC contents （ P 〈 0. 05） . However, a significant decrease in both TN and TP contents was observed only in culti-vated lands with fissures and woodlands with fissures. The results suggest that ground fissures accelerated the depletion of soil C , N and P pools in both subsidence cultivated lands and woodlands, especially for the C pool depletion. In the case of being fissures, the conversion of woodlands from cultivated lands may reduce C pool depletion in subsidence mine soil. In the circumstance of being no fissure, in contrast, the conversion increase soil C pool depletion.