Technical ArticleField Testing a Mobile Inelastic Neutron Scattering System to Measure Soil CarbonYakubova, Galina1; Wielopolski, Lucian2; Kavetskiy, Aleksandr1; Torbert, H. Allen1; Prior, Stephen A.1Author Information 1U.S. Department of Agriculture–Agricultural Research Service National Soil Dynamics Laboratory, Auburn, Alabama, USA. 2Brookhaven National Laboratory, Environmental Sciences Department, Upton, New York, USA. Address for correspondence: Dr. Galina Yakubova, USDA-ARS National Soil Dynamics Laboratory, 411 South Donahue Dr, Auburn, AL 36832, USA. E-mail: [email protected] Financial Disclosures/Conflicts of Interest: None reported. Received August 4, 2014. Accepted for publication December 29, 2014. Soil Science: December 2014 - Volume 179 - Issue 12 - p 529-535 doi: 10.1097/SS.0000000000000099 Buy Metrics Abstract Cropping history in conjunction with soil management practices can have a major impact on the amount of organic carbon stored in soil. Current methods of assessing soil carbon based on soil coring and subsequent processing procedures before laboratory analysis are labor intensive and time-consuming. Development of alternative methods that can make in situ field measurements of soil carbon is needed to successfully evaluate management practices in a timely manner. The robust design, field testing procedure, and results of measuring soil carbon in situ using a mobile inelastic neutron scattering (MINS) system are described. A method of MINS spectra data processing that gives more accurate peak area determination compared with the traditional “trapezoidal” method is described. The MINS reliable autonomous operation for 29 h per charge cycle was demonstrated in the field. For comparison, soil cores were also collected for laboratory carbon analysis using the dry combustion technique. Soil carbon assessments by dry combustion technique and MINS demonstrated a linear correlation between the two methods in the 0- to 30-cm soil layer. Based on the developed theoretical model of MINS measurement, we demonstrated that accurate soil carbon determination by this method depends on carbon distribution within the soil and MINS signal errors. Copyright © 2014 Wolters Kluwer Health, Inc. All rights reserved.