植被更替及植果年限对土壤有机质和酶活性的影响

土壤有机质及酶活性是反映植被更替对土壤质量作用与影响较为敏感的指标,对分析制约地区苹果产业可持续发展因素具有重要意义。在彬县果区土壤及地形条件与管理水平基本一致的条件下,以农田土壤(对照)与8年(幼龄)、21年(老龄)果园为研究对象,研究其0～40 cm土层深度内的有机质、过氧化氢酶活性、脲酶活性、碱性磷酸酶活性的变化趋势。结果表明,土壤有机质、脲酶和碱性磷酸酶活性随土层深度的增加而减少。在0～40 cm土层范围内,农田演替为果园,降低了土壤有机质含量、过氧化氢酶和碱性磷酸酶活性,增加了土壤脲酶活性。随着种植年限的增加,有机质含量在0～20 cm土层出现累积趋势,过氧化氢酶活性减少,而碱性磷酸酶和脲酶在剖面上呈现不同程度的递减趋势。因此,在0～40 cm土层植被更替及植果年限对土壤生物质量影响明显,可能会对果树生长产生影响。

Effect of vegetation replacement and planting years on soil organic matter and enzyme activity

Soil organic matter and enzyme activity are sensitive indexes to reflect the effect and influence of vegetation replacement on soil quality, which are great significance to analyze the factors restricting the sustainable development of apple industry in the region. So soils in farmland (control), 8a (young orchard) and 21a (old orchard) apple orchards in Bin County were collected from 0-40 cm soil depths, which the terrain condition and management level under the same conditions. The soil organic matter content and the activities of catalase, urease activity, and alkaline phosphatase were measured. The results showed that the soil organic matter content, activities of urease and alkaline phosphatase decreased with the increase of soil depth. Within the 0-40cm soil layer, the farmland converting to orchard reduced the content of soil organic matter, catalase and alkaline phosphatase activities, and increased the urease activities. With the increase of planting years, the organic matter content in 0-20cm soil layer showed a cumulative trend, and catalase activity decreased, while alkaline phosphatase and urease showed a decreasing trend to different degrees in profile. Therefore, vegetation replacement and fruit planting years in 0-40cm soil layer had obvious effects on soil biological quality, which may affect the growth of fruit trees.