00292nam a2200085Ia 4500041001200000082001100012082001100023100002000034245015200054  aEnglish  a631.45  bYOU/PO  aAnthony   Young 4aICRAF working paper No.44: the potential of agroforestry for soil conservation part.3- Soil changes under agroforestry (scuaf) : a predictive model