Abstract

The responses of four steppe forage species in the Pashylogh rangeland to precipitation timing were assessed for a period of 7 years (2003 to2007 and 2009 to 2010). Regression analysis was used to examine the relationship between annual production and different periods of precipitation. Annual yields of the different steppe forage species responded differently to the periods of precipitation. Precipitation during November to December and April to May gave the highest predictor of total forage production (r²= 0.80). Annual productivity of Salsola arbosculoformis was most closely correlated with precipitation in November to December and April to May (r² = 0.86), Artemisia seiberi with November to January (r² = 0.68), Salsola tomentosa in January (r² = 0.72) and Astragalus podolobus with from the end of the growing season in previous year and the new growing season (r² = 0.88). This study supported the use of seasonal period precipitation instead of annual precipitation in effectively estimating the herbage production through a statistical model.

Key words: Precipitation, forage, yield, Pashylogh.