Speaker
Description
Primary cosmic rays are high-energy particles that enter the Earth’s atmosphere via the heliosphere,
which generate cascades of secondary cosmic-ray particles when interacting with atmospheric
atoms. These secondary cosmic-rays interact inversely with hydrogen atoms in soil moisture,
providing a non-invasive method for monitoring moisture levels. Continuous measurements
of neutron flux in soil can establish predictive models for heatwaves, droughts, and floods that
significantly impact South Africa’s agricultural sector. This study employs a cosmic-ray neutron
sensor (CRNS) probe equipped with a Boron trifluoride (BF3) detector positioned 1-2 m above
ground that is capable of measuring soil moisture across a footprint of approximately 20 hectares
width and up to 0.3 m depth. We detail the calibration process relating measured neutron intensity
to volumetric water content, validated against gravimetric soil sampling and point sensor data,
which will assist in precision agriculture that can enhance water resource management in diverse
agricultural landscapes across South Africa.
