War in Ukraine affects the soil

Some of the most fertile lands in the world, the so-called black lands of Ukraine, are being rendered useless by Russian bombings. Grain production fell by half in a year of war.

War not only kills and injures men: it also mutilates the earth. The effect is more pernicious, less impressive than a destroyed building surrounded by rubble, but very devastating. As the Russian army begins a new offensive, Ukrainian territory displays the many scars of a year of war: charred tanks on the sides of roads or in the middle of fields, fields disfigured by shells and mines, forests torn apart by the passage of trenches. The effects of the invasion on the soil of Ukraine, the breadbasket of wheat and corn on the European continent, are already visible – and quantified.

According to the Ukrainian Grain Association (UGA), the cultivated area was reduced by a quarter between 2021 and 2022 due to the Russian invasion, which made sowing difficult. For this year, the forecasts are lower: the UGA anticipates a cereal and oilseed harvest of around 53 million tons in 2023, against 65 million tons in 2022 (and 106 in 2021).

Passing military vehicles and missile impacts harm the fertile land, "polluted by chemicals from explosive materials and fuel", notes Vitaliy Privalov, a Ukrainian geologist who joined the GeoRessources laboratory (University of Lorraine - CNRS) last spring.

A true national treasure, the famous chernosols ("chernozems", literally "black earth", in translation from Russian "chorny" + "zemlya") are particularly affected.

“Russia has turned them into the most polluted land in the world,” says Anatolii Kucher, professor at the Ukrainian Research Institute of Soil Science and Agrochemistry (NSC ISSAR). Rich in organic matter and minerals, chernosols have a great capacity for absorbing metals and petroleum derivatives. Its biological properties are today degraded by pollution from oxides of chromium, copper, nickel, lead and petroleum from weapons.

"Metallic compounds actively migrate underground, creating channels and traps where dangerous and toxic products accumulate for the environment. Soil absorption reaches a saturation level", explains Vitaliy Privalov, who worked in Donetsk until 2014 and then in Dnipro.

"The processes of natural detoxification and restoration of fertility of chernosols are relatively slow, so the purification mechanisms can last decades or longer. 'Man and animals through the food chain'," adds Kateryna Smirnova, researcher at NSC ISSAR.

“Even before the start of Russian aggression in February 2022, in Donbass, which has been systematically bombed since 2014, we recorded systematic exceedances of chemical pollution values”, notes the professor-researcher at the GeoRessources laboratory.

Studies carried out on the soils of the liberated territories of the Kharkiv region confirm this. In areas where "active hostilities" occurred, the levels of some metals were higher than pre-invasion levels: cadmium (4 to 18 times), lead (3 to 22 times), copper (6 to 12 times), nickel (2 to 4 times) and chromium (2 to 3 times), according to statements by researcher Valentina Samokhvalova (NSC ISSAR).

The long-term environmental consequences of the Russian invasion for the ground remain difficult to assess, as they depend on the duration and progress of the fighting. "A third of Ukraine's forest fund, or about three million hectares, has already suffered from the war," estimates Vitaliy Privalov.

Due to fires at oil and gas storage facilities, exploration wells, coal mines, dangerous combustion products enter the air, soil and groundwater. Not to mention the areas permanently contaminated by unexploded ordnance, the number of which is "greater than in Syria and Afghanistan", explains Privalov.

"There are anti-tank and anti-personnel mines, land mines, cluster munitions and a large number of unexploded grenades", lists the geologist. Around a third of the country is expected to be cleaned up, "which will take at least ten years."

There is a term to describe the unique form of land destruction resulting from war: bomturbation. The concept was first introduced in 2006 by geomorphologist Joseph Hupy and geologist Randy Schaetzel. It describes the formation of craters on the surface of the ground and their mixing by the explosion of ammunition and other more or less heavy artillery. Scientists analyzed the case of the Battle of Verdun during World War I, where explosions fractured the shallow bedrock. Changes in the morphology of the landscape, the concentration of certain metals and erosion due to the conflict are still tangible a century later. Will it be the same for Ukraine?

"I would say that the term 'bombturbation' is much more restricted than the reality caused by the Russian invasion. There is a difference in scale and use of weapons compared to the First World War. The negative impacts are much greater today", continues geologist Vitaliy Privalov.

In Donbass (east of the country), where mining activity has been intense for a long time, the soil has already undergone several changes due to this industry. The conflict, which began in this region in 2014, worsened the situation. "Chernosols have suffered and are still suffering irreparable military degradation. It is very difficult to overcome it", three Ukrainian experts wrote in 2021 in an article published in an agricultural newspaper.

Once the war ends, these territories will require "post-demining studies and detailed risk assessments, measures to accelerate the rehabilitation of soil health and special environmental monitoring", judges Kateryna Smirnova. “Everything can be fixed,” insists Vitaliy Privalov. "It's just a matter of finding the funds needed to solve the problem."