Soil enzyme activities and abundance of microbial functional genes involved in nitrogen transformations in an organic farming system
Soil enzyme activities and abundance of microbial functional genes involved in nitrogen transformations in an organic farming system
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DOI：
10.1007/s00374-018-1272-y
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发表时间：
2018-05-01
影响因子：
6.5
通讯作者：
Norton, Jeanette M.
中科院分区：
文献类型：
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作者：
Ouyang, Yang;Reeve, Jennifer R.;Norton, Jeanette M.
有机农业系统接受有机修正以保持土壤肥力并为植物生长提供养分。在有机生产系统下，研究了有机肥（无添加剂对照、堆肥和粪肥）及其与覆盖作物（谷子、荞麦和黑龟豆）互作对土壤酶活性、氮转化速率和功能基因丰度的影响。有机肥对土壤功能和功能基因丰度的影响强于覆盖作物类型。堆肥和粪肥处理均能提高土壤酶活性，但差异不大。有机肥处理土壤的硝化势、亚硝酸盐氧化势和反硝化势显著高于对照和堆肥处理土壤，表明有机肥施用比堆肥施用具有更高的氮损失势。有机肥显著增加了与氮矿化、氨化和硝化有关的基因（sub、ureC、细菌amoA和nxrB）的丰度。有机肥处理均能提高氨氧化细菌和古细菌的活性，且有机肥处理的活性高于堆肥处理的活性。总体而言，功能基因的丰度与其对应的酶活性显著相关。然而，在解释相应酶活性的变化时，功能基因丰度不如土壤化学和微生物特性重要。
Organic farming systems receive organic amendments to maintain soil fertility and supply nutrients for plant growth. This study investigated the effect of organic fertilizers (no amendment as control, compost, and manure), and their interaction with cover crops (millet, buckwheat, and black turtle bean) on soil enzyme activities, N transformation rates, and functional gene abundances under an organic production system. Organic N fertilizers had a stronger effect than cover crop type on soil function and functional gene abundances. Soil enzyme activities were increased by both compost and manure, but there were few differences between these treatments. Nitrification potential, nitrite oxidation potential, and denitrification potential were significantly higher in manure-treated than in control and compost-treated soils, indicating application of manure had a higher N loss potential than compost application in this organic farming system. Organic N fertilizers significantly increased the abundance of some genes involved in N mineralization, ammonification, and nitrification (sub, ureC, bacterial amoA and nxrB). The activity of ammonia-oxidizing bacteria and archaea were both increased by organic N fertilizers, and their activities were higher in manure-treated than in compost-treated soils. Overall, the abundance of functional genes was significantly correlated with their corresponding enzyme activity. However, functional gene abundance was less important than soil chemical and microbiological properties in explaining the variation in the corresponding enzyme activity.