Organic nitrogen components in soils from southeast China
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To investigate the amounts of extractable organic nitrogen (EON), and the relationships between EON and total extractable nitrogen (TEN), especially the amino acids (AAs) adsorbed by soils, and a series of other hydrolyzed soil nitrogen indices in typical land use soil types from southeast China. Under traditional agricultural planting conditions, the functions of EON, especially AAs in the rhizosphere and in bulk soil zones were also investigated.
Pot experiments were conducted using plants of pakchoi (Brassica chinensis L.) and rice (Oryza sativa L.). In the rhizosphere and bulk soil zone studies, organic nitrogen components were extracted with either distilled water, 0.5 mol/L K2SO4 or acid hydrolysis.
K2SO4-EON constituted more than 30% of TEN pools. K2SO4-extractable AAs accounted for 25% of EON pools and nearly 10% of TEN pools in rhizosphere soils. Overall, both K2SO4-EON and extractable AAs contents had positive correlations with TEN pools.
EON represented a major component of TEN pools in garden and paddy soils under traditional planting conditions. Although only a small proportion of the EON was present in the form of water-extractable and K2SO4-extractable AAs, the release of AAs from soil exchangeable sites might be an important source of organic nitrogen (N) for plant growth. Our findings suggest that the content of most organic forms of N was significantly greater in rhizosphere than in bulk soil zone samples. However, it was also apparent that the TEN pool content was lower in rhizosphere than in bulk soil samples without added N.
Key wordsExtractable organic nitrogen Amino acids Rhizosphere Bulk soil
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- Bai, H.Y., Xiao, J.Z., 1998. Experimental Research and StatisticalzAnalysis. World Book Press, Xi’an, China, p.120–128 (in Chinese).Google Scholar
- Bremner, J.M., 1965. Organic Forms of Nitrogen. In: Black, C.A. (Ed.), Methods of Soil Analysis. American Society of Agronomy, Madison, p.1238–1255.Google Scholar
- Ge, T.D., Song, S.W., Roberts, P., Jones, D.L., Huang, D.F., Iwasaki, K., 2009. Amino acids as a nitrogen source for tomato seedlings: the use of dual-labeled (13C, 15N) glycine to test for direct uptake by tomato seedlings. Environ. Exp. Bot., 66(3):357–361. [doi:10.1016/j.envexpbot.2009.05.004]CrossRefGoogle Scholar
- Ke, Q.M., Lin, W.X., Huang, Z.F., Fang, J.L., Huang, M.Q., 2005. Simulation on the mathematical model of balanced fertilization in Pakchio vegetable crop. Chin. J. Eco-Agric., 13(1):119–121 (in Chinese).Google Scholar
- Keeney, D.R., 1982. Nitrogen—Availability Indices. In: Page, A.L., Miller, R.H. (Eds.), Methods of Soil Analysis. Part 2: Chemical and Microbiological Properties. SSSA, Madison, p.711–730.Google Scholar
- Keeney, D.R., Nelson, D.W., 1982. Nitrogen—Inorganic Forms. In: Page, A.L., Miller, R.H. (Eds.), Methods of Soil Analysis. Part 2, 2nd Ed. ASA and SSSA, Madison, WI, p.643–698.Google Scholar
- Lu, R.K., 1999. Soil Chemical Analysis Methods in Agriculture. China Agricultural Sciences and Technical Press, Beijing, China (in Chinese).Google Scholar
- McDowell, W.H., Magill, A.H., Aitkenhead-Peterson, J.A., Aber, J.D., Merriam, J.L., Kaushal, S.S., 2004. Effects of chronic nitrogen amendment on dissolved organic matter and inorganic nitrogen in soil solution. For. Ecol. Manage., 196(1):29–41. [doi:10.1016/j.foreco.2004.03.010]CrossRefGoogle Scholar
- Olsen, S.R., Cole, C.V., Watanabe, F.S., Dean, L.A., 1954. Estimation of Available Phosphorus in Soils by Extraction with Sodium Bicarbonate. USDA Circular 939. US Department of Agriculture, Washington, DC, USA, p.1–18.Google Scholar
- Russell, R.S., 1982. Plant Root Systems, 1st Ed. McGraw-Hill, p.214.Google Scholar
- Shi, G.R., 2004. Ecological effects of plant root exudates. Chin. J. Ecol., 23(1):97–101 (in Chinese).Google Scholar
- Stevenson, F.J., 1982. Nitrogen-Organic Forms. In: Page, A.L. (Ed.), Methods of Soil Analysis, Part 2. Madison, WI, American Society Agronomy, p.625–641.Google Scholar
- Stevenson, F.J., 1994. Humus Chemistry: Genesis, Composition, Reactions. John Wiley and Sons Inc., New York, p.443.Google Scholar
- Willett, V.B., Green, J.J., Macdonald, A.J., Baddeley, J.A., Cadisch, G., Francis, S.M.J., Goulding, K.W.T., Saunders, G., Stockdale, E.A., Watson, C.A., et al., 2004. Impact of land use on soluble organic nitrogen in soil. Water Air Soil Poll., 4(6):53–60. [doi:10.1007/s11267-004-3013-5]CrossRefGoogle Scholar
- Wu, L.H., Mo, L.Y., Fan, Z.L., Tao, Q.N., Zhang, F.S., 2005. Absorption of glycine by three agricultural species under sterile sand culture conditions. Pedosphere, 15(3):286–292.Google Scholar
- Yang, R., Yan, D.Y., Zhou, J.B., Wang, W.X., Ma, Q.A., 2007. Soluble organic nitrogen (SON) in different soils on the loess plateau of China. Acta Ecol. Sin., 27(4):1397–1403 (in Chinese).Google Scholar