Sodium hydroxide direct distillation: A method for estimating total nitrogen in soil

Citation

Sharifi, M., Zebarth, B.J., Burton, D.L., Grant, C.A., Hajabbasi, M.A., Abbassi-Kalo, G. (2009). Sodium hydroxide direct distillation: A method for estimating total nitrogen in soil. Communications in Soil Science and Plant Analysis, [online] 40(15-16), 2505-2520. http://dx.doi.org/10.1080/00103620903111376

Abstract

Soil total nitrogen (N) concentration is commonly measured by Kjeldahl and combustion methods. In this study, a method based on determination of ammonium (NH4)-N produced by steam distillation of the soil sample with sodium hydroxide solution (NaOH-DD) is developed and evaluated for estimating soil total N concentration. The method was evaluated using two sample sets: (A) 44 samples collected from contrasting land uses in central Iran and (B) 344 samples collected from contrasting arable soils across Canada and Maine, USA. Based on this experiment, 10-min distillation of 5.0 g soil with 20 mL 12.5 M NaOH were selected as the optimum conditions. The NH4-N released by the NaOH-DD method was highly correlated with total N concentration in the sample sets A and B (r = 0.79 and 0.94, respectively). The NaOH-DD method provides a simple, rapid means of analysis with reduced measurement cost and better health and safety precautions than the traditional Kjeldahl method. © Taylor & Francis Group, LLC.

Publication date

2009-11-24

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