This Small Business Innovation Research (SBIR) Phase I project will investigate the ability of prompt gamma neutron analysis (PGNA) techniques to provide in situ subsurface (0-48 inches) localized (<1m2 resolution) scanning of soil nitrogen/nutrient/water concentrations and soil properties in real-time for precision agricultural field mapping. Existing sampling and chemical assay field mapping techniques provide only near-surface (<6 inch depth) aerially-sparse data. This allows application of only a coarsely tailored top-dressing of fertilizer. With high-resolution and depth information, fertilizer and soil usage can be fully optimized to reduce cost and maximize yield. The combined benefits of an electronic neutron generator that uses no radioactive material and the elemental analysis capabilities of PGNA would result in a safe and effective soil scanning technology. The primary objective of this Phase I project is to determine the expected sensitivity of the soil analyzer using MCNP modeling. These sensitivity results will, in turn, set the requirements for the neutron generator and gamma-detection systems.
The broader impact/commercial potential of this project is reduction in overall fertilizer use, ability to improve plant nutrient uptake, and, consequently, higher yields, leading to an estimated value proposition of $8 Billion annually for the agriculture industry (based on 2008 data). A key aspect of Phase I work will be to assess the commercial viability of a PGNA-based soil scanner and gauge market acceptance to determine the expected fraction of this value that can be captured relative to production costs to ascertain commercial feasibility. In addition to monetary returns, reductions in fertilizer run-off and better soil management will yield an environmental payoff in the form of a more sustainable and productive agriculture industry that benefits everyone.
This Small Business Innovation Research Phase I project investigated the concept for an "active" scanning system to measure soil elemental composition and moisture content for use in precision and smart farming. Today nitrogen, phosphorous and potassium are added to the soil surface without clear understanding if the fertilizer is used efficiently. The standard technique is labor intensive and involves physically extracting several core samples with a hand auger over a hectare. The soil samples are mixed together in a plastic container and shipped to a chemical testing laboratory for destructive analysis. After several weeks, the resulting data gives a gross average on the chemical composition for that hectare. Since soil variations occur over meters, the standard approach cannot be scaled to the sampling sizes needed for smart farming and precision fertilizer application. Research estimates only 33% of applied nitrogen is captured by plants, resulting in >4M metric tons lost to U.S. rivers, lakes and atmosphere; the annual economic cost is over $50 billon for nitrogen alone. An in-situ system to measure nutrients and assess soil quality in the root zone is needed to enable farmers to select management options to minimize waste and improve output. Neutrons are sub-atomic particles that can penetrate the ground and interact in the top meter of soil to give off characteristic emissions representative of what is present in the soil. New non-radioactive, long-life neutron generators could be used with suitable gamma-ray detectors to assess N-P-K levels, water content, soil porosity, micronutrient levels, and contaminants on a per-meter basis. The Phase I program successful met its planned milestones, simulating detection thresholds, source strengths and the viability of two different approaches for in-situ analysis. One of the approaches was a clear winner and will serve as the basis for a Phase II development prototype system since it may lead to advances in agricultural conservation, production efficiency, and food production. This work has also fostered educational and mentorship opportunity for students in a research laboratory setting. This work has fostered cooperation between academic faculty at a leading University, an agricultural farming cooperative that embraces advanced technology for smart farming, a Fortune 500 agricultural equipment maker, and a company specializing in environmental assessment, resource management, conservation and sustainability.
