Pesticide residues increase in Estonian agricultural soils

Pesticide residues are becoming more prevalent in Estonian agricultural soils, although their concentrations remain below legal limits, ERR reported, citing the Environmental Agency.

Soil condition directly affects food production, water movement, biodiversity and climate balance. The Environmental Agency said soil is a limited resource whose formation takes longer than a human lifetime.

Martin Maddison, an adviser at the Environmental Agency, said changes in soil occur slowly and require long-term, consistent data to understand. The agency coordinates soil monitoring to track changes in Estonian agricultural soils caused by natural factors.

“Soil monitoring is intended to track soil health indicators and detect changes in time, because then appropriate measures can be taken to help the soil recover,” Maddison said.

Most of the indicators measured in the agricultural soils studied were good. Soil acidity was within a range suitable for plant growth, levels of primary nutrients were sufficient and heavy metal concentrations remained below established target values. No significant changes were found in the thickness of the humus layer.

However, long-term monitoring data and the results from 2025 point to changes requiring attention, Maddison said. These include a decline in organic carbon, an accumulation of phosphorus, soil compaction and the presence of pesticide residues.

“Recent monitoring results show that pesticide residues are increasingly detectable in the soil. The concentrations are low and do not reach the legal limits, but they are becoming more visible with each passing year,” Maddison said.

The concern is that the pesticides being used may accumulate in the soil and eventually affect soil organisms.

Last summer was exceptionally rainy. The gley soils examined in the monitoring programme are naturally moist, and heavy rainfall can quickly fill their pores with water. During sampling, the soil was very wet, leaving many areas with too little air for plants and soil organisms.

This can affect plant growth. When soil pores fill with water, organisms in the soil lack oxygen and their activity slows, preventing plants from absorbing nutrients. As a result, a soil may contain sufficient nutrients but still be saturated and unable to support a crop until harvest, Maddison said.

Frequent rainfall is also visible in fields where crops have been flattened. “Heavy rains destroy the harvest,” Maddison said.