Low Nitrogen Losses with a New Source of Nitrogen for Cultivation of Conifer Seedlings
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- 作者：Jonas Ö ; hlund and Torgny Nä ; sholm
- 刊名：Environmental Science & Technology
- 出版年：2002
- 出版时间：November 15, 2002
- 年：2002
- 卷：36
- 期：22
- 页码：4854 - 4859
- 全文大小：109K
- 年卷期：v.36,no.22(November 15, 2002)
- ISSN：1520-5851
文摘
Losses of nitrogen (N) when cultivating plants may causea number of adverse environmental effects. N lossesfrom conifer nurseries, for instance, may have a considerableimpact on the local environment, and studies indicatethat the bulk of added N is not recovered in the cultivatedplants. This study was conducted to obtain insight intothe causes of the low recovery and to test an alternativeN fertilizer. Hence, growth of the economically importantScots pine (Pinus sylvestris (L).) seedlings and the recoveryof different forms of added nitrogen (N) were investigatedin a greenhouse experiment. Containerized seedlingswere grown in peat for one summer, with two different Nfertilizers, one organic (arginine) and one inorganic (acommercial fertilizer (CF) containing a mixture of ammoniumand nitrate) each at an N concentration of 3 mM. At theend of the growth period, some seedlings were labeledwith solutions containing either U-[13C6], [15N4]-arginine,(15NH4)2SO4, or K15NO3 supplied to the growth substrate.Labeled seedlings were harvested 1 h, 5 days, and 19 daysafter tracer addition, and the recovery of each addednitrogen source in both the seedlings and the growthsubstrate was measured. The retention of the three N formsduring discharge of solutions from the growth substrate,peat, was tested in a separate experiment. Arginine-fed seedlings grew better and had higher needle Nconcentrations than the CF-fed seedlings. Isotopic datashowed that the arginine treatment gave significantly higherN recoveries (80%) compared to the CF treatment (50%).The low recovery of N in the CF treatment was largely dueto very low recovery (30%) of NO3- -N. The retention ofthe different N forms during discharge of solutions from thegrowth substrate was highest for arginine, somewhatlower for NH4+, and very low for NO3-. The high rate ofseedling growth and the small nitrogen losses observedwhen using arginine suggest that this amino acid maybe an efficient and environmentally favorable N source forcultivating conifer seedlings.