Soil conditions directly affect food production, water movement, biodiversity and the climate balance, yet at the same time soil is a finite resource. Similar to fossil fuels, soil takes many times more than a human lifespan to properly form.

Martin Maddison, an adviser with the agency, said changes in soil, including natural and not human-made ones, also take place slowly, and that keeping abreast of these requires long-term, consistent data. To keep track of soil health, the agency coordinates monitoring aimed at studying changes in Estonia's agricultural soils resulting from natural factors.

"Soil monitoring is intended to track soil health indicators and identify changes in time, as then appropriate measures can be taken to help restore the soil to health," he said.

The indicators for the agricultural soils under survey at least turned out to be generally good, Maddison said. Soil pH was within a range suitable for plant growth, levels of essential nutrients were sufficient and concentrations of heavy metals remained below established target values. There were also no significant changes in the thickness of the humus horizon – the upper layer of soil rich in dark, decayed organic matter and which is needed for strong plant growth.

At the same time, long-term monitoring data and the 2025 results highlight changes that Maddison said do require attention. These include declining organic carbon levels, phosphorus accumulation, soil compaction and the presence of pesticide residues.

"Recently, monitoring results have shown that pesticide residues are increasingly being picked up in the soil. It is true that concentrations are low and do not reach the limit values. But at the same time, they are being detected more and more with each passing year," Maddison said. This could turn into a problem as the pesticides being used may begin to accumulate in the soil, potentially affecting soil organisms in the future, he added.

Last summer was exceptionally rainy. The gley (a type of sticky, waterlogged clay – ed.) soils examined in the monitoring program tend to be naturally moist, and during heavy rainfall their pores can quickly fill with water. At the time the samples were taken, the soil was indeed very wet, and in many areas there was little air left in the soil for plants and soil organisms to propagate.

All of this can impact plant growth. Pores in the soil, which can account for as much as 60 percent of the overall soil volume, quickly fill with water, leaving soil organisms deprived of oxygen and slowing biological activity, which means plants are unable to absorb nutrients from the soil. As a result, even otherwise fertile soil containing sufficient nutrients can become saturated. "The plant cannot then access those nutrients, and as a result the growing plant dies as it does not even have time to mature enough to be harvested," Maddison said.

Beyond that, the most immediately visible effect of frequent rainfall is, for example, crops being flattened in grain fields. "Heavy rains destroy the crop," Maddison noted.

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