充填与非充填开采条件下煤矿沉陷区耕地土壤质量空间分布规律研究

为了研究煤矿井下充填开采是否能有效保护地表耕地土壤环境,保持土壤肥力,本文以皖北矿业集团公司五沟煤矿充填开采工作面与非充填开采工作面为试验区,在2个工作面对应上方地表分别划分试验区域和对照区域,进行采样、相关土壤指标检测及结果分析。试验区域(充填开采)包括:地表沉陷区坡脚B1处(点1?~点3?)、沉陷区坡面B2处(点4?~点6?)、沉陷区坡顶B3处(点7?~点9?);对照区域(非充填开采)包括:地表沉陷区坡脚A1处(点1~点3)、沉陷区坡面A2处(点4~点6)、沉陷区坡顶A3处(点7~点9)。每个区域分别在9个采样点内按照0~20 cm、20~40 cm和40~60 cm 3个土壤深度分层采集土样,对土壤理化性质以及该区域小麦株高和经济产量进行了测定和分析。试验结果显示,充填开采区域土壤碱解氮、有效磷、速效钾和有机质在3个土层的平均含量均高于非充填开采区域。试验观测期间,3月份B1处小麦株高小于A1处,5—6月B2和B3处小麦长势均优于A2和A3处,直至收割;小麦成熟时,充填开采区域经济产量高于非充填开采区。充填开采区域地块土壤含水量高于非充填开采区域。因此,本文认为充填开采比非充填开采更能保持开采区域上覆土壤的养分和水分。但与正常土壤背景值相比,充填开采区域上覆土壤仍存在某些营养元素(如有机质及磷元素)含量不足的问题,其作为农耕地需要加强人工活动的影响,如增施肥料、加强田间管理等。

Spatial distribution regularities of farmland soil quality in subsidence areas of coal filling mining and non-filling mining

Correlation research results showed that underground filling coal mining can effectively alleviate ground surface settlement in coal mining areas. To study whether filling coal mining was effective in protecting surface soils in cultivated lands, especially the ability of effectively maintaining soil fertility, an investigation was conducted in CT101 filling working face and 1013 non-filling working face in Wugou Coal Mine of Northern Anhui Mining Group. The test region and control region were set in the corresponding surfaces above the filling mining working face and non-filling working face. The two regions both non-filling area (A) and filling mine area (B)] included division A₁ or B₁ in slope base of surface subsidence (point 1 to point 3 ), division A₂ or B₂ in middle subsidence slope (point 4 to point 6 ) and division A₃ or B₃ at top edge of subsidence (point 7 to point 9 ). In accordance with nine sampling points of each regions, each point was separately sampled at three soil depths 0-20 cm (H1), 20-40 cm (H2) and 40-60 cm (H3)] and two parallel samples collected for each depth, totaling 108 samples in the two regions. By this way, the physical properties (including soil bulk density and water content) and nutrients (including organic matter, available nitrogen, available phosphorus and available potassium contents), the height and yield of wheat in the two regions were analyzed. The results showed that nutrients contents of surface soil in the test region were higher than those in the control region. Based on observations during the experimental period, wheat growth in zones B₂ and B₃ was better than that in zones A₂ and A₃ from May to June until harvest. However, this was not the case for wheat height in zone B₁, which was shorter than that in zone A₁ in March. Wheat yield was higher in B zones than that in A zones at harvest. Soil moisture in the test region was higher than that in the control region. The analysis showed that mine filling activity had a stronger ability than non-filling in holding nutrients and water in overlying soils in mining areas. This was critical for the protection of land and the environment. Compared with normal soil background values, however, the overlying soils of mine filling area still exhibited some problems with nutrients contents such as organic matter and available phosphorus. With regards any effect on agriculture field, mine filling areas needed strengthened artificial activities such as addition of fertilizers, strengthening of field management, etc.