黄土高原不同种植年限苜蓿地土壤酶活性的季节性变化研究

Seasonal variation of soil enzyme activity of alfalfafield with different planting ages on Loess Plateau

摘要:

研究黄土高原长期种植紫花苜蓿地的土壤酶活性季节性变化,同时测定紫花苜蓿种植1、2、4、11和16年土壤中的脲酶、碱性磷酸酶、蔗糖酶和过氧化氢酶的活性。结果表明:土壤脲酶、碱性磷酸酶、过氧化氢酶和蔗糖酶的活性受到紫花苜蓿的种植年限、季节和土层深度的影响。不同种植年限紫花苜蓿地土壤酶活性与季节呈显著相关,土壤脲酶和碱性磷酸酶的活性表现为6月较高,蔗糖酶活性3月较高,而过氧化氢酶活性差异不显著。紫花苜蓿地土壤酶活性具表层富集性,在0~5 cm 土层中脲酶、蔗糖酶和磷酸酶活性高于5~10 cm 土层的1~3倍,而过氧化氢酶酶活性在土层之间差异不显著。种植4年紫花苜蓿地土壤酶活性较高,种植11、16年的土壤酶活性显著下降。可见,种植紫花苜蓿达10年以上土壤酶活性下降明显,需加强人工牧草地管理。

Abstract:

The seasonal dynamics of soil enzyme activity in alfalfa field with different planting ages in LoessPlateau were studied.The activity change of soil urease,alkaline phosphatase,invertase and catalase were measuredin alfalfa fields with 1,2,4,11 and 16 planting ages.The results showed that the soil enzyme activitychanged seasonally with different planting ages,the activity of soil urease,alkaline phosphatase and catalase wasthe highest in June,the invertase activity was the highest in March;the soil enzyme activity when alfalfa wasplanted for 4 years increased obviously,and it significantly decreased in 16 years.The activity of soil invertase,urease and phosphatase in 0~5 cm soil layer was 1 to 3 times higher than that in 5 to 10 cm,while catalase activitydid not significantly change between 0~5 cm and 5~10 cm layer.