EARTHWORM EFFECTS ON N DYNAMICS AND SOIL RESPIRATION IN MICROCOSMS RECEIVING ORGANIC AND INORGANIC NUTRIENTS
EARTHWORM EFFECTS ON N DYNAMICS AND SOIL RESPIRATION IN MICROCOSMS RECEIVING ORGANIC AND INORGANIC NUTRIENTS
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DOI：
10.1016/0038-0717(94)00184-3
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发表时间：
1995-03-01
影响因子：
9.7
通讯作者：
EDWARDS, CA
中科院分区：
文献类型：
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作者：
BOHLEN, PJ;EDWARDS, CA
本研究设计了一个微观实验，研究蚯蚓对土壤氮素循环过程和微生物活性的影响。圆柱形微型宇宙包含16个。田间收集的土壤，接受3种养分改剂中的1种，以150 kg N ha（-1）的速率在土壤上部5 cm处添加：(1)粒状NH4NO3肥料；(2)稻草包装的牛粪；(3)风干野豌豆（Vicia villosa）豆科渣。每种营养处理不添加蚯蚓4个重复，每个微群落（蚓蚓与结核无齿蚓混合群落）添加21条蚯蚓4个重复。孵育112 d。连续测定土壤呼吸，定期测定0-5和5-15 cm处可提取的NO3-、NH4+和微生物生物量n。蚯蚓对土壤NO3-可提取量有显著影响，且随时间增加而增加，其中施用NH4NO3肥料的土壤NO3-可提取量最大，施用豆科植物残渣的土壤NO3-可提取量最小。在最终取样日（112 d），蚯蚓在0-5 cm土壤深度的NO3-可提取量分别增加了NH4NO3、粪肥和豆类的1.83倍、1.88倍和1.26倍。112天后，蚯蚓在0-5 cm土壤深度的可提取NH4+量分别比施用NH4NO3、肥料和豆类的蚯蚓增加了1.60倍、4.00倍和1.30倍。蚯蚓显著降低了5 ~ 15 cm土壤深度的微生物生物量n，且在施用了NH4NO3和粪肥处理的微生物群落中效果最大。土壤呼吸速率在前15天增加了1.24 ~ 2.42倍，土壤累积呼吸速率（ll2 d）分别增加了1.84倍、1.37倍和1.24倍。这些结果表明蚯蚓通过取食微生物生物量增加了可提取氮的量，并增加了微生物组织的周转和矿化。
We designed a microcosm experiment to investigate the effects of earthworms on N cycling processes and microbial activity, in soil receiving organic or inorganic nutrient amendments. Cylindrical microcosms contained 16 1. of field-collected soil that received 1 of 3 nutrient amendments, added to the upper 5 cm of soil at a rate of 150 kg N ha(-1): (1) granular NH4NO3 fertilizer; (2) straw-packed dairy cow manure; and (3) air-dried hairy vetch ( Vicia villosa) legume residue. There were 4 replicates of each nutrient treatment without earthworms, and 4 replicates with a total of 21 earthworms added per microcosm (a mixed community of Lumbricus terrestris and Aporrectodea tuberculara). The microcosms were incubated for 112 days. Soil respiration was measured continuously and extractable NO3- and NH4+ and microbial biomass-N were measured, periodically, at 0-5 and 5-15 cm. Earthworms had significant effects on amounts of extractable NO3-, which increased with time, and were greatest in soil that received NH4NO3 fertilizer and least in soil that received legume residues. On the final sample date (112 days), earthworms increased amounts of extractable NO3- at the 0-5 cm soil depth 1.83-, 1.88- and 1.26-fold in microcosms supplied with NH4NO3, manure and legume trestments, respectively. Earthworms increased the amounts of extractable NH4+, after 112 days, at the 0-5 cm soil depth, by 1.60-, 4.00- and 1.30-fold, in microcosms that had received the NH4NO3, manure and legume treatments, respectively. Earthworms significantly reduced the amounts of microbial biomass-N at the 5-15 cm soil depth, and this effect was greatest in microcosms that had received the NH4NO3 and manure treatments. Earthworms increased soil respiration rates during the first 15 days by from 1.24- to 2.42-fold and increased cumulative soil respiration (ll2 days) by 1.84-, 1.37- and 1.24-fold, respectively, in microcosms treated with the fertilizer, manure and legume treatment. These results indicate earthworms increased the amounts of extractable N by feeding on the microbial biomass, and increasing the turnover and mineralization of microbial tissues.