Text Correction
There were several errors in the original publication [
1].
To enhance clarity, the publication title has been revised from “Improved Method for Extracting Nitrites in Soil” to “Adaptation of NO2− Extraction Methods to Different Agricultural Soils: Fine-Tuning Based on Existing Techniques”.
In the fourth line of the Abstract, the use of the word “optimization” in the original text may lead to inaccurate representation. In order to avoid misunderstanding, a correction has been made to the Abstract and should read as follows:
“In order to reflect the soil NO2− concentration more accurately, we made minor adjustments on the basis of the existing soil NO2− extraction method, so that it can be adapted to agricultural soils with different textures and pH values (alkalic fluvo-aquic soil, acidic Mollisol, and Ultisol soils, respectively). Both extractable soil ammonium (NH4+) and nitrate (NO3−) were systematically investigated to refine the simultaneous extraction of soil inorganic nitrogen.”
Given the specific conditions of the samples, the oscillation times were fine-tuned appropriately. A correction has been made to the Abstract, line 17, and should read as follows:
“In conclusion, soil NO2− extraction was carried out by DIW extraction, shaking for 10 min, and filtering with a 0.45 µm filter, while soil NH4+ and NO3− were extracted with a KCl solution and shaken for 30 min. The extract should be stored at 4 °C and analyzed within 24 h. We have made minor adjustments to our previously published method for soil NO2−analysis to make it more adaptable to soils with different textures and pH values. These adjustments make the method more effective in soil geochemical nitrogen cycling studies, especially in the assessment of soil nitrite (HONO) and nitric oxide (NO) emissions.”
To ensure that the work keeps pace with the latest scientific advances, changes have been made to the Introduction, on the first line of the third paragraph, and should read as follows:
“Although DIW has become the recommended extractant for soil NO2− analysis, the presence of suspended solids in the DIW extract affects the absorbance measurements of NO2− analyzed spectrophotometrically, thus requiring filtration through a 0.45 μm filter [20].”
Meanwhile, the third sentence of the second paragraph, “During the extraction of NO2−, there are generally no biological or chemical reactions that cause changes in its concentration or isotopic composition [21].” has been deleted. Reference [21] corresponds to [24] in the latest version.
The method published by Homyak et al. (2015) is already a validated and recommended standardized procedure. It is on this solid foundation that our study was conducted, and minor adjustments have been made to ensure the validity and accuracy of the measurements of NO2− in the soils tested. A correction has been made to the Introduction, on the fourth paragraph, and should read as follows:
“Therefore, this study aims to verify the effectiveness and accuracy of the latest soil NO2− detection method in soils with different textures and pH values in order to provide a scientific basis for the efficient extraction of NO2−, NO3− and NH4+.”
In the Discussion section, Section 4.1, line 17, there were some errors in the presentation of the article. The corrected section should read as follows:
“In conclusion, unbuffered KCl solutions considerably reduced NO2− concentrations, in agreement with previous studies [16,20]. Although more NO2− can be extracted with DIW, it produces a brown extract that interferes with colorimetric analysis [20]. Homyak et al. (2015) [20] obtained more accurate measurements of NO2− concentration by filtering through a 0.45 micron filter [20].”
In the first line of the Conclusion, there are some errors in the presentation of the article. To ensure the accuracy of the content, the relevant paragraphs have been revised and should read as follows:
“We have fine-tuned our published soil NO2− extraction methods to make them applicable to agricultural soils of different textures and pHs.”
References
The previously cited references [23–25], as listed below, have been removed.
23. Maynard, D.G.; Kalra, Y.P.; Crumbaugh, J.A. Nitrate and exchangeable ammonium nitrogen. In Soil Sampling and Methods of Analysis, 2nd ed.; Carter, M.R., Gregorich, E.G., Eds.; CRC Press: Boca Raton, FL, USA, 2007; pp. 71–80, ISBN 9780849335860.
24. Pansu, M.; Gautheyrou, J. Handbook of Soil Analysis: Mineralogical, Organic and Inorganic Methods; Springer: Berlin/Heidelberg, Germany; New York, NY, USA, 2006; pp. 767–792, ISBN 978-3-540-31210-9.
25.
ISO 14256-2:2005; Soil Quality Determination of Nitrate, Nitrite and Ammonium in Field-Moist Soils by Extraction with Potassium Chloride Solution-Part 2: Automated Method with Segmented Flow Analysis. ISO: Geneva, Switzerland, 2005. Available online:
https://www.iso.org/obp/ui/#iso:std:iso:14256:-2:ed-1:v1:en (accessed on 12 December 2023).
As a result of this correction, the order of several references has been adjusted accordingly.