Photo credit: Peter Trimming

Small mammals can provide agricultural benefits by eating weed seeds or they can act as pests by eating crop grains. A new study published in the Journal of Applied Ecology sought to tease apart the effect of organic and conventional farming on these benefits and challenges caused by small mammals. Researchers compared the effects of farming system and crop characteristics such as wheat density and height on the abundance of mice and voles and the amount of weed seed removal from fields vs. the amount of wheat crop seed removal. Researchers collected data on crop characteristics and small rodent populations from German organic and conventional wheat farms, and used experiments to determine the amount of seed removal and crop damage caused by rodents.  The study found that voles were primarily responsible for crop damage, removing almost three times more wheat seeds than weed seeds. Mice removed more weed seeds. However, the magnitude of their benefit was not affected by the farming system. On the other hand, voles and their associated crop damage were lower in organic fields than conventional fields due to the lower density and height of wheat plants.