Agricultural Geophysics News, Vol 26.1

Agricultural Geophysics News

Angelo Lampousis, Ph.D.

War on soil?

Welcome back to our agricultural geophysics column. The coincidence of the current FastTIMES special issue with recent research evaluating the long term effects of unexploded ordnance (UXO) on agricultural soils was not by design. It can still give us all pause and an opportunity to reflect on establishing new aspirational agricultural geophysics goals that would free agricultural lands from the pervasive negative effects of UXO.

Erin Lin of Ohio State University along with three other researchers of the same institution observed an interesting correlation between soil fertility and the relative occurrence of UXO. According to their 2020 study that appeared in the Public Library of Science (PLoS) more fertile, soft soils have a higher probability of having UXO as opposed to less fertile soils. Cambodian agriculture is the case in point since the heavy bombing by the United States that occurred during the Vietnam war. An unknown number of munitions that have not exploded are still inside the country’s richest soils. Author Erin Lin noted that “There is often nothing more damaging to a national economy than war on its own soil. But the way we, as social scientists, typically think about the long-term economic effects of war is often tied up in other factors, like political insecurity, destruction of infrastructure, and rebel disarmament. This leads us to overlook something important: long-term damage to agriculture” (April 2021, personal communication.) 

Near surface geophysics are absent from these studies (see references for complete citations) since the methods employed include primarily satellite imagery and subsequent analysis that is common in the remote sensing literature.  Agricultural geophysics have an obvious advantage here, namely to prioritize the agricultural lands in need of clearing from UXO based on perceived or established soil fertility criteria. In a country like Cambodia that according to The Economist (March 20th, 2021) has the world’s highest rate of amputees it would help a great deal to at least reduce the adverse long-term economic consequences of high fertility land that remains the least productive due to UXO.


Lin, Erin, (2020) “How war changes land: Unexploded bombs, soil fertility, and the underdevelopment of Cambodia.” Harvard Dataverse, V

Lin E, Qin R, Edgerton J, Kong D (2020) Crater detection from commercial satellite imagery to estimate unexploded ordnance in Cambodian agricultural land. PLoS ONE 15(3): e0229826.

The Economist: American bombing 50 years ago still shapes Cambodian agriculture, March 20th,  2021.