... such as 'alley cropping.' It means more effort and a reduced farming space (the trees take maybe 10%), but rows of fast-growing easy-to-manage poplars divide some German farms now.
The trees 'sequester' co2 (and therefore mitigate climate change). Hens enjoy the forest floor, and eat the greenery there, which reduces co2 because most of the co2 associated with farming chickens comes from producing the feed (partially, because some of their feed is still bought). The hens trample fallen leaves and the soil regains nutrients. The roots of the tree also improve soil quality, and trees form a wind break so soil isn't blown away, and anchor moisture into the ground, and (with the shrubbery planted beside the strips of trees, like multiyear wildflower) provide a habitat for beneficial insects like hoverflies, dung beetles, and wild bees, and worms and fungi.
So three things--chicken farming, producing feed for them, and having trees to convert co2 to oxygen (and glucose) are now done in one location, so less land needed and less transportation costs.
However, a lot of the trees are eventually chopped down to 20cm once they are fully grown, and burnt as firewood, rereleasing 70% of their co2, which mitigates their mitigation of co2.
The first year after planting trees on a farm field takes more work, because you have to tend the area around the tree shoots so they can live.
There are some farming areas where the ground is not thick enough to really have large trees, though, and watery rice fields and hilly regions also aren't always idea for trees.
Familiar facts: 25% of greenhouse gas emissions come from agriculture. Monoculture sucks nutrients out of soil. Farms take up a lot of land. Using lots of trees on farms was historically practiced everywhere but went out of fashion in the early 20th century, when it was seen as inefficient (tractors and machinery played a part).
-dashboard-02">EEA: Greenhouse gas emissions by aggregated sector