Estimates of water erosion were obtained by using the average values of erosion rates per crop given in Table 1, together with agriculture land use data provided by the Brazilian Geographical and Statistical Institute IBGE (2009). In the case of cotton, sugar-cane, cassava and degraded pasture (Table 2), data on erosion rates were derived from experimental studies outside Brazil, since no other information was available for these crops. Such information was sought, however, for regions with climate and soil similar condition to those of Brazil. For degraded pasture, a value of 12 t ha− 1 yr− 1 was based on information shown in Table 2. It can be seen from this table that rates of soil loss from degraded pasture are 30 times greater than those from non-degraded pastures. Thus the erosion rate from degraded pasture was taken to be thirty times greater than the 0. 4 t ha− 1 yr− 1 found experimentally in Brazil.