黄土高原不同坡位苹果林土壤酶活性及微生物量动态变化研究

Seasonal Changes of Soil Microbial Biomass and Soil Enzyme Activities at Different Slope Positions of Apple Grove on the Loess Plateau

为了从生物学角度揭示坡地经济林不同坡位土壤质量的差异,研究黄土高原坮塬区旱作苹果园不同坡位土壤酶活性及微生物量随季节的变化特征。结果表明:不同坡位土壤酶活性及微生物量碳、微生物量氮等存在显著差异(P<0.05);土壤脲酶、蔗糖酶、碱性磷酸酶活性表现为下坡位>上坡位>中坡位;过氧化氢酶活性下坡位>中坡位>上坡位;微生物量碳、微生物量氮下坡位>上坡位>中坡位。除过氧化氢酶外,其他土壤酶活性和微生物量受季节影响显著(P<0.05),同坡位碱性磷酸酶表现为秋季>盛夏>初夏>春季>冬季,脲酶、蔗糖酶、微生物量碳、微生物量氮表现为盛夏>秋季>初夏>春季>冬季。土壤养分、地温、光照条件是导致该地区不同坡位土壤酶活性、微生物量出现差异的主要原因,下坡位土壤生物学质量及生态条件较好,适宜种植苹果等经济林作物。

In order to reveal the difference of soil quality in different forest slope positions from the bi ological view,this study investigated the seasonal changes of soil enzyme activities and microbial bio mass at different slope positions of apple grove in Chunhua county on the Loess plateau. The results indicated that soil enzyme activities, microbial biomass were significantly affected by slope positions （P〈0.05）. The urease,invertase and alkaline phosphatase activities were in the order, lower slope upper slopemiddle slope. The catalase activity was in the order： lower slope〉middle slopeupper slope. The microbial biomass carbon and microbial biomass nitrogen were in the order, lower slope upper slope〉middle slope. The soil enzyme activities and microbial hiomass were also significant different with the seasonal change （P〉0.05）. The alkaline phosphatase activity was in the order： au tumn〉midsummer〉early summer〉spring〉winter,and the urease,invertase activities and microbial biomass were in the order. midsummer〉autumn〉early summer〉spring〉winter. However,catalase activity varied little with seasonal change. The present study demonstrated that soil nutrient level, soil temperature and light condition were the main factors causing the difference of enzyme activities andmicrobial biomass at different slope position. The lower slope has a better soil biological quality and ecological conditions than the upper slope and middle slope soil, and was suitable for planting apple and other economic forest crops.