infertile Soil depletion Soil Fertility Soil Fertility fertile soil infertile Soil depletion fertility fertility topsoil loss http://en.wikipedia.org/wiki/Fertility_(soil) Soil depletion fertile Soil depletion Soil depletion පසේ සරුබවයි (soil fertility) Soil depletion fertile says Soil Fertility fertile half the topsoil has been lost Fertility soil depletion half the topsoil has been lost fertile soil depletion http://en.wikipedia.org/wiki/Fertility_(soil) fertility Soil depletion http://en.wikipedia.org/wiki/Fertility_(soil) soil fertility