Agricultural Compendium for Rural Development in the Tropics and Subtropics

according acid agricultural annual applied approximately average calculated capacity cause characteristics classes classification clay climate complete concentration costs crop density depends depth determined direction discharge distribution drain drainage effect erosion evaporation example exchangeable factors fertility field formation formula given gives horizon important improvement increase indicated irrigation land layer less limited losses lower material mean measured mechanical method mineral moisture months needed observations obtained occur operation organic matter percentage period plant possible potential practical present processes production properties rainfall ratio readings reference result rock root salinity salt sample sand saturation scale season seed slope soil Source specific structure suitability supply surface survey Table temperature units usually values various vegetation vertical volume weeds weight wind yields