Cambios De Vegetacion Y Costos Asociados Con El Continuo Sobrepastoreo Del Ganado En El Pastizal Mediano Abierto De Cananea, Sonora, México

Short Grass Prairies are very important ecosystems for society because they offer many services that impact production and well-being of the people. The continuous overgrazing in this community has reduced the density and cover of grasses and increased the density and coverage of mesquite, reducing the production potential and transforming the condition of the pasture from good to poor. An economic analysis was carried out to evaluate the profitability of a ranch with Short Grass Prairies in poor condition (SGPPC), compared to a ranch with Short Grass Prairies in good condition (SGPGC) and an option that includes the planting of buffel grass (Cenchrus ciliaris L.) (PBG). Three ranches of 1,000 ha were considered, similar in management, two of which, one was in good condition and the other in poor condition, work according to their current production capacity. In the other option, the pasture was improved annually by planting 200 ha of buffel. A financial program with a 14-year projection was used. In all cases, real costs were calculated. The results show that the average annual economic yield in the SGPPC varied from $ 1.51 to $ 6.92 pesos/ha and in the SGPGC it varied from $72.60 to $137.86 pesos/ha and both remained relatively stable during the 14 years. The profitability in SZB was negative during the first five years, until the investment of range seeding and cattle was paid, and until the seventh year, it reached the point of stabilization. The average annual economic yield in the rehabilitated ranch was $274.80 pesos/ha, and it was 64.2 and 3.2 times higher than the ranch with Short Grass Prairie in poor and good condition, respectively. We conclude that continuous overgrazing causes severe changes in vegetation and reduces the productivity and condition of pastures. It is not economically feasible to overgraze Short Grass Prairies because yields are reduced and over time are economically unsatisfactory to sustain a family. The planting of buffel grass is a good alternative to rehabilitate deteriorated pastures.