The roots anchor the soil and parts above ground reduce soil and sand movement. Intercropping perennials with annuals leads to better use of light, water and nutrients due to the different spacing, height and root depth of the plants. Faidherbia albida is already well known for improving nitrogen and organic matter of the soil beneath its canopy. These are species that grow naturally in the semi-arid and arid areas of Africa. Perennials also reduce sheet erosion and increase water penetration on hard soils by slowing water flow on slopes.
Perennials protect annuals from desiccating winds.
One farmer whose field was sheltered from the prevailing wind by perennials growing at Eden's field station, recorded a millet yield three times as high as another farmer whose field was exposed to the wind. That year, many farmers had to resow several times because the strong wind destroyed their seedlings. On the contrary, the farmer whose field was sheltered only had to resow the part of his field that was furthest away from the field station. In this way his millet grew taller and gave a higher yield than the others' millet. Edible perennials have the distinct advantage of providing food in drought years when the annual crops fail.