添加杨柳树枝对沙化土壤有机碳、含水量及微生物活性的影响

Effects of adding poplar and willow branches on organic carbon, moisture and microbial activities of sandy soil

以宁夏银川腹部的沙化土壤为研究对象,设计了添加杨树粉碎材料(B)、添加杨树粉碎材料+覆盖柳树枝条(C)和覆盖树枝混合粉碎材料(D)3种方式进行沙化土壤的处理,并以不做任何处理的土壤(A)为对照,测定了土壤中有机碳含量、含水量、微生物数量和酶活性。结果表明,B、C和D处理措施均能显著提高土壤含水量、有机碳含量、微生物(细菌、真菌和放线菌)数量(P<0.05),其中细菌和放线菌数量增加最明显。B和C处理能显著增加土壤中脲酶和过氧化氢酶的活性(P<0.05),D处理土壤中脲酶活性小于对照,过氧化氢酶活性与对照土壤无显著差异(P>0.05)。相关性分析表明,土壤含水量、有机碳含量和细菌、真菌、放线菌数量以及脲酶、过氧化氢酶活性相关性显著(P<0.05)。可见,添加有机物对修复沙化土壤、增加土壤微生物活性有显著作用。

Taking sandy soil of Yinchuang, Ningxia Hui Autonomous Region as research object, the organ- ic carbon content, moisture, microbial quantity and enzyme activities of soils, that were treated with different methods, including without any treatment（A, control）, adding poplar woody chips（B）, adding poplar woody chips＋covering with willow branches（C） and covering with mixed woody chips of poplar and willow（D）, were tested in this study. The results indicated that, treatments of B, C and D could significantly increase soil organic carbon content, moisture and microbial quantity（bacteria, fungi and actinomyces）, especially the quantity of bacteria and actinomyces. The activities of urease and catalase were largely improved by treatment B and C. However, the urease activity of treatment D was lower than that of control, and the catalase activity treatment D had no significant difference with control （P〉 0. 05）. The results of correlation analysis indicated that, there were significant correlations among soil organic carbon content, moisture, bacterial quantity, fungi quantity, actinomyces quantity, urease activity and catalase activity（P〈0.05）. So adding organic matters can significantly improve sandy soil and increase soil bacterial activities.