Description of the Business As Usual (BAU)
The “Business as Usual” land use is conventional arable farming. This is defined by Eurostat as land worked regularly, generally under a system of crop rotation with cereals, pulses, root crops, etc. This system typically involves intensive management, including regular tillage or herbicide use to maintain monocultures, which can lead to soil erosion and organic matter loss in the absence of woody perennials.
Description of the system change
Alley cropping involves planting wide-spaced rows of trees or shrubs with herbaceous crops grown in the alleys between them. This transitions a single-story monoculture into a two or more-strata system. The trees act as windbreaks, nutrient-cycling and filtering tools, and soil-carbon pumps. The intercropped alleys continue to produce annual yields. This spatial arrangement allows for high-value timber or fruit production alongside arable crops, significantly increasing the total carbon stored per hectare. Normally, crop production will be complementary to the trees, but it is important to prune the lower branches of the trees to reduce competition for light, water, and nutrients. Pruning also improves the form and value of the timber. Surface tree roots can be controlled by ploughing and subsoiling. If done at regular intervals, this causes little check on the growth of the trees.