Responses of absolute and specific soil enzyme activities to long term additions of organic and mineral fertilizer.
Responses of absolute and specific soil enzyme activities to long term additions of organic and mineral fertilizer.
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DOI：
10.1016/j.scitotenv.2015.07.043
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发表时间：
2015-12
期刊：
影响因子：
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通讯作者：
Xinyu Zhang;Wenyi Dong;Xiaoqin Dai;S. Schaeffer;Fengting Yang;M. Radosevich;Li-Li Xu-Li;Xiyu Liu
中科院分区：
文献类型：
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作者：
Xinyu Zhang;Wenyi Dong;Xiaoqin Dai;S. Schaeffer;Fengting Yang;M. Radosevich;Li-Li Xu-Li;Xiyu Liu
长期施磷(P)和施氮(N)会严重影响土壤微生物活性。1998年，在中国南部亚热带地区的红壤水稻土上进行了长期田间施肥试验。我们研究了猪粪和七种不同比例的NPK肥料处理对(1)参与C、N、P转化的单位土壤有机碳(SOC)或微生物生物量碳(MBC)的绝对和特定酶活性的影响，以及(2)它们与土壤环境因素和土壤微生物群落结构的关系。结果表明，有机肥能提高土壤β-1，4-葡萄糖苷酶(βG)、β-1，4-乙酰氨基葡萄糖苷酶(NAG)和亮氨酸氨基肽酶(LAP)的绝对活性和比活性。绝对酸性磷酸酶(AP)活性和比酸性磷酸酶(AP)活性随着磷肥施用量和比例的增加而降低。冗余度分析表明，AP绝对活性与比活性、pH、全P含量呈负相关，βG、NAG、LAP酶活性与土壤绝对活性、土壤有机碳、全N含量呈正相关。RDA显示，放线菌和革兰氏阳性菌PLFA生物标志物的含量与酶的绝对活性和特定酶活性的相关性比其他PLFA生物标志物更密切(P<；P<；0.01)。我们的结果表明，绝对和特定的酶活性都可以作为敏感的土壤质量指标，提供与微生物群落结构和环境因素的有用联系。为了保持微生物活性和最大限度地减少对环境的影响，磷应以无机和有机形式结合使用，亚热带水稻土的总磷肥施用量不应超过44公斤/公顷−和1年−/1。
Long-term phosphorus (P) and nitrogen (N) applications may seriously affect soil microbial activity. A long-term field fertilizer application trial was established on reddish paddy soils in the subtropical region of southern China in 1998. We assessed the effects of swine manure and seven different rates or ratios of NPK fertilizer treatments on (1) the absolute and specific enzyme activities per unit of soil organic carbon (SOC) or microbial biomass carbon (MBC) involved in C, N, and P transformations and (2) their relationships with soil environmental factors and soil microbial community structures. The results showed that manure applications led to increases in the absolute and specific activities of soil β-1,4-glucosidase(βG), β-1,4-N-acetylglucosaminidase (NAG), and leucine aminopeptidase (LAP). The absolute and specific acid phosphatase (AP) activities decreased as mineral P fertilizer application rates and ratios increased. Redundancy analysis (RDA) showed that there were negative correlations between absolute and specific AP activities, pH, and total P contents, while there were positive correlations between soil absolute and specific βG, NAG, and LAP enzyme activities, and SOC and total N contents. RDA showed that the contents of actinomycete and Gram-positive bacterium PLFA biomarkers are more closely related to the absolute and specific enzyme activities than the other PLFA biomarkers (P< 0.01). Our results suggest that both the absolute and specific enzyme activities could be used as sensitive soil quality indicators that provide useful linkages with the microbial community structures and environmental factors. To maintain microbial activity and to minimize environmental impacts, P should be applied as a combination of inorganic and organic forms, and total P fertilizer application rates to subtropical paddy soils should not exceed 44 kg P ha− 1year− 1.