Growth response and nitrogen use physiology of Fraser fir (Abies fraseri), red pine (Pinus resinosa), and hybrid poplar under amino acid nutrition
Plants can assimilate amino acids from soils. This has been demonstrated in controlled environments and soils of various forest ecosystems. However, the role of root-absorbed amino acids in plant nitrogen nutrition is still poorly understood. We investigated the agroecological performance and nutrient use physiology of two conifers (Abies fraseri and Pinus resinosa) and one hardwood species (hybrid poplar) under amino acid fertilization. Arginine fertilizer (arGrow® Complete) was applied at varying rates (0, 56, 112, 224, and 336 kg N/ha) and compared to an inorganic control treatment (ammonium sulfate 112 kg N/ha). Parameters monitored included tree growth response, foliar nitrogen concentration, and inorganic nitrogen leaching below the rootzone. Results obtained indicate a significant growth and foliar nitrogen response to amino acid treatments, with increasing amino acid application leading to greater growth and foliar nitrogen. However, rates two to three times higher than that of the inorganic control were necessary to provide similar growth and foliar nitrogen responses. These observations were suggested to be due to competition with soil microbes for organic nitrogen, growth inhibition due to the presence of large concentrations of amino acids, or adsorption to cation exchange sites. Amino acid applications did not increase the leaching of inorganic nitrogen due either to the binding of positively charged arginine cations to exchange sites or rapid mineralization followed by plant assimilation. Mineral nitrogen collected in leachate samples increased with the application rate suggesting at least some mineralization in high amino acid application rates. We conclude that growth response and nitrogen use physiology of these species when treated with arginine are largely controlled by soil processes including microbial competition and adsorption. Further studies are being conducted to confirm these hypotheses.
KeywordsOrganic nitrogen Arginine Nitrogen leaching Tree nutrition Short rotation cropping systems
Special thank to SweTree Technologies for providing the Amino Acid Fertilizer used in this study and for technical support. This study was financially supported by the MSU AgBioResearch Station and the Michigan Seedlings Growers Association.
- Dannenmann M, Simon J, Gasche R, Holst J, Naumann PS, Kogel-Knabner I, Knicker H, Mayer H, Schloter M, Pena R, Polle A, Rennenberg H, Papen H (2009) Tree girdling provides insight on the role of labile carbon in nitrogen partitioning between soil microorganisms and adult European beech. Soil Biol Biochem 41:1622–1631CrossRefGoogle Scholar
- Lloyd JE, Herms DA, Rose MA, Van Wagoner J (2006) Fertilization rate and irrigation scheduling in the nursery influence growth, insect performance, and stress tolerance of ‘Sutyzan’ Crabapple in the landscape. HortScience 41:442–445Google Scholar
- Näsholm T, Huss-Danell K, Hogberg P (2000) Uptake of organic nitrogen in the field by four agriculturally important plant species. Ecology 81:1155–1161Google Scholar
- Nikiema P, Nzokou P, Rothstein D (2011) Effects of groundcover management on soil properties, tree physiology, foliar chemistry and growth in a newly established Fraser fir (Abies fraseri [Pursh] Poir) plantation in Michigan, United States of America. New Forests. doi: 10.1007/s11056-011-9274-8 Google Scholar
- Smith SE, Read DJ (2008) Mycorrhyzal symbiosis, 3rd edn. Academic Press, New YorkGoogle Scholar
- Timmer VR (1991) Interpretation of seedling analysis and visual symptoms. In: van den Driessche R (ed) Mineral nutrition of conifer seedlings. CRC Press, Boca Raton, pp 113–134Google Scholar