Scanning mode application of neutron-induced gamma analysis for soil carbon mapping

Inventors

Chin, Bryan A. • Torbert, III, Henry Allen • YAKUBOVA, GALINA N. • KAVETSKIY, ALEKSANDR • Sargsyan, Nikolay

Assignees

US Department of Agriculture USDA

Abstract

A system for analyzing soil content of a field includes a data acquisition unit configured to detect gamma spectra of each of a plurality of soil samples, wherein a surface area of the field is divided into a plurality of portions and the plurality of soil samples comprises at least one soil sample from each of the plurality of portions, a navigation unit configured to detect geographic coordinates of each of the plurality of soil samples, a data analysis unit configured to associate the detected gamma spectra of each of the plurality of soil samples with the geographic coordinates of the soil sample and determine a weight percent of at least one element within each of the soil samples based on the detected gamma spectra, and an element content map unit configured to generate a map indicating concentration of the at least one element within the soil of the field.

Core Innovation

The invention provides a system and method for analyzing soil content of a field using neutron-induced gamma analysis. The system includes a data acquisition unit configured to detect gamma spectra from multiple soil samples taken from divided portions of the field. A navigation unit detects geographic coordinates of each soil sample, and a data analysis unit associates the gamma spectra with geographic positions to determine the weight percent of at least one element within each soil sample. Additionally, an element content map unit generates maps indicating concentrations of elements within the soil field.

The problem being solved arises from limitations in conventional soil elemental content analysis, where only tiny portions of the field are sampled and composited, often less than 0.01% of the field area, leading to high-level approximations of soil content. Current systems are not adaptable for analyzing numerous samples to enhance accuracy. Since accuracy of elemental content is crucial for agricultural and environmental purposes such as determining nutrient needs and carbon credits, there is a need for a methodology that yields more detailed and accurate elemental content information across a given field area.

The invention addresses this problem by dividing the field surface into portions and scanning at least one soil sample from each portion using neutron-induced gamma analysis, associating gamma spectral data with geographic coordinates, and calculating elemental concentrations to generate precise distribution maps. The system incorporates a neutron generator and gamma detectors, potentially on mobile platforms, combined with GPS to scan and map elemental distributions such as carbon, silicon, oxygen, hydrogen, and potassium with high accuracy and reproducibility.

Claims Coverage

The patent contains three independent claims which define systems and methods for analyzing elemental soil content by collecting gamma spectra correlated to geographic coordinates, calculating element weight percentages, and generating elemental distribution maps with specific features for spectral correction and data processing.

The independent claims cover systems and methods integrating gamma spectral detection with geographic data to accurately calculate soil elemental content and generate distribution maps. Key inventive features include spectral energy correction, use of averaged detector lifetimes for calculation, and data association with geographic midpoints to produce precise soil element concentration maps.

Stated Advantages

Documented Applications