Root crops must be dug in and dug out. Unfortunately, modern population pressures and land-ownership uncertainties are creating situations of land scarcity that make long fallows infeasible for most. The soil degradation resulting from shortened fallows is affecting productivity and increasing dependencies on food imports such as rice and flour in many areas. Trees planted and managed in hedgerows provide the same products and services as those that were allowed to grow during traditional fallow periods. Trees cycle nutrients from deeper in the soil profile by shedding organic matter on the surface as leafy and woody litter or 'green manure'.
Litter rebuilds a soil's structure making it less erodible and more able to absorb and hold water.
Hedgerows also yield other products such as fuelwood and fodder. They create a more favorable micro-climate for crops by shielding them from drying winds. Hedges planted on slopes, also anchor soil and form terraces, preventing the loss of precious topsoil by heavy rains and the overland flow of water. Traditional systems combined trees with crops on the same piece of land in a time sequence. The tree and crop components are managed so as to be complimentary rather than competitive.