Year round vegetative cover of soils

Traditional farmers often employ a system of continuous vegetative cover of the soils as either green manures or mulches. The green manures are generally leguminous plants, grown to be plowed into the soil prior to planting. Alternatively, crops can be planted concurrently with green manures with minimal soil disturbance. Mulches are generally waste plant materials, such as leaf litter, branches, straw, compost, aquatic weeds or decaying plants, spread on the ground around the base of the crops. Benefits of mulching and green manures include: (Stigter 1984, Thurston 1992)
  • Shading the soil reduces moisture loss.
  • Reduced rain splash decreases pathogen dispersal.
  • Wind and rain induced soil erosion is reduced.
  • There is continuous addition of organic matter to the soil.
  • Leguminous green manures provide inputs of nitrogen.
  • Weeds are suppressed.
  • Cover protects crops at seedling stage.
  • The cover provides microhabitats for natural enemies of pests and increases trophic complexity
  • Green manures can provide animal fodder and human food
  • Soil temperatures are reduced.