نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
دانشگاه صنعتی اصفهان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسنده [English]
The location of extracellular enzymes with the soil architecture and their association with the various soil components affects their catalytic potential. Amidohydrolases including L- glutaminase, L- asparaginase, Urease, Amidase and L-aspartase play important roles in mineralization of nitrogen. This study was conducted to: investigate aggregate distribution of L- glutaminase, L- asparaginase and Urease in different ecosystems including Gisum forest, Delvara forest. A wet sieving procedure was used to separate soil aggregate into classes of >2, 2- 1, 1- 0.5, 0.5- 0.25 and 0.25- 0.1; Soil amidohydrolases which are thought to be of different origins were measured in the separated aggregates as well as soil organic C (SOC). Results indicated that in the Gisum forest, pine standing has resulted in increasing SOC content. Moreover, The activity of L- glutaminas and Urease were similar in the both standings, but the activity of L- asparaginase was greater in the maple standing compared to the pine standing. The enzyme activities enhanced as the aggregate size increased in both pine and maple standings. In the Delvara oak forest, the enzyme activities showed to be highly sensitive to management practices, while enzyme activities and organic carbon decreased significantly as cultivation practiced in the Delvara ecosystem. This study showed that soil management practices, including tillage would enhance the mass fraction of either small macroaggregate or microaggregates and therefore would significantly affect soil biological and biochemical properties, which may lead to changes in nitrogen cycling, including N mineralization in soil aggregates.
کلیدواژهها [English]
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