Agroforestry project

Multiple climate benefits from agroforestry

The Paris climate goals are not only achieved by cutting emissions of fossil greenhouse gases. Also effective methods for removing carbon dioxide from the atmosphere are needed. Farming methods, which absorb carbon faster and more permanently from the atmosphere to the soil than conventional farming, have been proposed as possible methods. One possibility is agroforestry where crops and trees are grown together.

The objectives of this project were:

(1) to evaluate the potential of tree avenues planted in croplands to uptake atmospheric carbon and also nitrogen in Finland

(2) to quantify the effect of trees on yields and the amount of nitrogen available in the soil.

The measuring site was located at Kilpiä Farm, Pusula, southern Finland. In the summer of 2019, the trees had an average height of 3 m. The measurements are made in several cross-sections on both sides of the tree avenues at distances of 0-12 meters. In addition to regular greenhouse gas exchange measurements over the growing season, we studied the effect of the trees on plant growth, i.e. biomass production, soil moisture and temperature, pH, pool and quality of carbon and nitrogen, microbial biomass and microbial species at different distances from the tree avenues.

The main results of the project

Various agroforestry practices could serve as important methods, especially when combined with other regenerative practices. In our case study, trees increased carbon accumulation of the ecosystem, and thus, the net emissions were estimated to be smaller than without the tree row. In addition, the tree row increased the presence and abundance of soil microbial communities.