煤矿沉陷区沉陷裂缝对土壤特性和作物生长的影响

为了研究煤矿沉陷区沉陷裂缝对土壤特性和作物生长的影响,通过野外调查和室内分析,对沉陷裂缝周围土壤水氮含量、微生物学特性和作物生理、产量特性进行了研究。结果表明,沉陷裂缝导致了土壤水、氮的流失。距沉陷裂缝越近,土壤含水量和有效氮含量越低,当距裂缝距离超过120 cm时,沉陷裂缝对土壤含水量和有效氮含量影响不显著。土壤水肥特性改变也导致了土壤微生物特性的改变,距沉陷裂缝越近,土壤酶(脲酶、蔗糖酶)活性和土壤呼吸速率越低。当距裂缝距离超过90 cm时,沉陷裂缝对土壤微生物的特性影响不显著。沉陷裂缝通过影响土壤中水分和矿物营养的含量,进而影响到植物叶片的叶绿素含量和光合特性。当裂缝距离超过60 cm时,沉陷裂缝对小麦叶片的叶绿素含量影响不显著。在拔节期,沉陷裂缝对光合作用的影响主要在距裂缝0~60 cm范围内,当距裂缝距离超过60 cm时,沉陷裂缝对小麦光合作用的影响不显著。但到花期时,当距裂缝距离超过90 cm时,沉陷裂缝对光合作用的影响不显著。沉陷裂缝对小麦各产量性状也造成了不同程度的影响。在距裂缝0~60 cm范围内,沉陷裂缝对株高、单茎重和穗粒数均有显著影响,当距裂缝距离超过90 cm时,则影响不显著。沉陷裂缝导致小麦穗数和产量的下降,距裂缝越近,小麦穗数和产量下降幅度越大,与距裂缝120 cm处小麦相比,裂缝边缘0~30 cm范围内小麦穗数和产量分别降低43.7%和53.3%。总之,开采沉陷产生的裂缝(隙),导致附近土壤水分蒸发增强和养分流失加剧,降低了土壤质量,影响到作物的生长,最终导致作物产量显著降低。

Effect of cracks on soil characteristics and crop growth in subsided coal mining areas

To determine the effects of cracks on soil characteristics and crop growth in subsided coal mining areas, field investigation and laboratory analysis were conducted for the contents of soil water and available nitrogen, soil microbial characteristics and physiological properties of crops at points with different distances from soil cracks. The results showed that soil cracks conduced to the loss of soil water and nitrogen. The closer the sampling site was to the soil cracks, the lower were the contents of soil water and available nitrogen. The cracks had no effect on the contents of soil water and available nitrogen at sampling sites beyond 120 cm from the cracks. The change in the contents of soil water and available nitrogen led to changes in soil microbial characteristics. The closer sampling site was to a soil crack, the lower were the activities of soil enzymes (urease and sucrase) and soil respiration rate. The crack had no effect on soil microbial characteristics at distances beyond 90 cm from the cracks. The crack had significant effect on chlorophyll content and photosynthetic rate of wheat, but had no effect on chlorophyll content of wheat at distances beyond 60 cm from the cracks. At jointing stage, the cracks showed a significant effect on wheat leaf photosynthetic rate within 0 60 cm from the cracks. The cracks had no effect on wheat leaf photosynthetic rate at distances beyond 60 cm from the cracks. However, at flowering stage, the crack had no effect on wheat leaf photosynthetic rate at distances beyond 90 cm from the cracks. The cracks had different effects on yield traits of winter wheat. The cracks had significant effect on plant height, unit stem weight and grain number per ear of wheat within 0 60 cm from soil cracks. The crack had no effect on yield traits of wheat at distances beyond 90 cm from the cracks. The crack reduced spike number and yield of wheat. The closer the sampling site was to the cracks, the higher was the reduction in spike number and yield of wheat. Compared with the distance of 120 cm from the cracks, spike number and yield of wheat within 0 30 cm from the cracks dropped by 43.7% and 53.3%, respectively. Thus soil cracks caused loss of soil water and nitrogen that in turn decreased soil quality and crop yield.