Farmers practiced polyculture, which involved mixing crops in the same field space (i.e., intercropping) and growing them at different times (i.e., crop rotation).
Farmers also recognized that farm animals, non-cultivated plants, birds, and soil flora and fauna are important components in agroecosystems and therefore protect and manage these. For example, geese were used to control weeds in gardens, and hens were used to control livestock parasites. Non-cultivated plants were used as primary producers, as shade plants, as temporary stores of nutrients, and to prevent growth of visceral parasites. Certain wild fauna are also protected (prohibition to harm) as their role in regulating pests or in pollination is recognized.
Crop rotation revitalizes the soils and prevent pest infestations. A typical crop rotation in Roslagen, includes perennial leys with nitrogen-fixating species. The timing and sequencing of crops are adjusted to soil type and field condition. Intercropping with leguminous plants enhances plant availability of nitrogen.
Local practices of mixing species and varieties have beneficial effects on crop production over time, especially by buffering climate variability and reducing pest damage. Indeed farmers identified the following benefits of intercropping:
1. Increases production
2. Enhances the supply of nutrients, especially nitrogen
3. Attracts insects and birds that control pests and diseases
4. Protects the crop against fungi by naturally occurring chemical compounds
5. Repels harmful insects by fragrance
6. Increases taste and aroma in the crop
7. Increases the content of ethereal oils in herbs
8. Increases crop quality in vegetables
9. Buffers for crop failure during climate irregularities