Next Article in Journal
Does Solar Radiation Affect the Distribution of Dubas Bug (Ommatissus lybicus de Bergevin) Infestation
Previous Article in Journal
Conservation of Crop Genetic Resources in Italy with a Focus on Vegetables and a Case Study of a Neglected Race of Brassica Oleracea
Article Menu
Issue 7 (July) cover image

Export Article

Open AccessArticle
Agriculture 2018, 8(7), 106; https://doi.org/10.3390/agriculture8070106

A Discussion on Mehlich-3 Phosphorus Extraction from the Perspective of Governing Chemical Reactions and Phases: Impact of Soil pH

1
USDA-ARS National Soil Erosion Research Laboratory, West Lafayette, IN 47907, USA
2
Oklahoma State University, Department of Plant and Soil Science, Stillwater, OK 74078, USA
3
Purdue University, Department of Agronomy, West Lafayette, IN 47907, USA
*
Author to whom correspondence should be addressed.
Received: 9 May 2018 / Revised: 15 June 2018 / Accepted: 26 June 2018 / Published: 2 July 2018
(This article belongs to the Special Issue Soil Fertility)
View Full-Text   |   Download PDF [1691 KB, uploaded 9 July 2018]   |  

Abstract

Mehlich-3 (M3) is one of the most common agronomic and environmental phosphorus (P) extractants for determining P fertilizer requirements and the potential for non-point source pollution. Understanding how soil properties impact M3 extractability can improve our ability to properly use this soil test. The objectives of this study were to investigate the impact of soil pH on P extractability by M3 and water in different soils containing equal total P, and to ascertain information about mechanisms of M3-P extraction. Soil pH at four field sites was previously adjusted to a range of approximately 4.5–7.5. Soils (Grant, Dale, Teller, Easpur) were characterized, and P was extracted with M3 and water. Extraction of Mehlich-3 P decreased 40% to 55% with increasing pH, which was potentially due to changing P forms, partial neutralization of extractant pH, and consumption of extractant fluoride (F) by non P-containing calcium (Ca) minerals. Water-soluble P (WSP) increased with increasing pH up to pH 6–7. Mehlich-3 P and WSP were not positively correlated except for one soil type. Mehlich-3 P is best utilized with WSP as indicators of quantity and intensity, respectively. Use of M3-P alone at pH < 5.5 may overestimate solubility. Further research should examine the suitability of M3-P at pH > 7. View Full-Text
Keywords: Mehlich-3; phosphorus; soil pH; phosphorus forms; phosphorus solubility; phosphorus extractions; phosphorus testing; soil testing Mehlich-3; phosphorus; soil pH; phosphorus forms; phosphorus solubility; phosphorus extractions; phosphorus testing; soil testing
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Penn, C.J.; Rutter, E.B.; Arnall, D.B.; Camberato, J.; Williams, M.; Watkins, P. A Discussion on Mehlich-3 Phosphorus Extraction from the Perspective of Governing Chemical Reactions and Phases: Impact of Soil pH. Agriculture 2018, 8, 106.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Agriculture EISSN 2077-0472 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top