Resumo

SILVA-BEJARANO, Christian  e  GARCILLAN, Pedro P.. Temporal variability of production of buffelgrass ( Cenchrus ciliaris L.) pastures in arid lands. Ecosistemas y recur. agropecuarios [online]. 2016, vol.3, n.9, pp.357-366. ISSN 2007-901X.

The establishment of buffelgrass pastures (Cenchrus ciliaris L.) has been considered a solution to the scarce availability of forage in arid lands. However, these regions are not only characterized by low productivity but also by its high temporal variability. That factor is not usually included in the estimation of pasture production. The objective of this study was to analyze the effect of including two sources of temporal variability (interannual variability of precipitation and effect of pasture age) in a model for estimating pasture productivity. Twelve pastures established during the 1970s in the Cape Region of Baja California Sur and distributed along an annual precipitation range of 100-450 mm were selected. The estimation model is based on the production - annual precipitation relationship. Interannual variability of precipitation was incorporated using the historical records of the weather station closest to each pasture. The effect of the age of establishment was incorporated following the age - productivity relationship reported in the literature. The results show that the effect of adding temporal variability increases the required precipitation threshold to obtain positive value of productivity, reduces significantly the estimated mean production by pasture, and increases it geographic variability.

Palavras-chave : Baja California; livestock; pasture run-down; variable precipitation; tree clearing.