Determination of production and consumption of range species in Badamestan rangelands of Zanjan province

Rangelands capacity depends on several factors, including the amount of forage production. Forage production varies during the grazing period and different years. The goal of determining grazing capacity is to estimate the forage production within the grazing period. This project was carried out over a period of 4 years (2006-2010) to determine forage production and consumption at different stages of growth. For this purpose, at the beginning of grazing season, the amount of forage remaining after grazing until the exit time of livestock was harvested at one-month intervals. Forage production was measured within the enclosed and adjacent area, and the amount of consumption of each species was determined. The collected data were analyzed based on a completely randomized design. The combined analysis of variance showed that production was significantly different (P<0.01) in years and months of the growing season. The highest amount of production was recorded in 2009 and the lowest in 2008. The ratio of forage produced in unfavorable to favorable years was 50%. In other words, forage production in 2009 was double that of 2008. This ratio was 13% to 79% among species. The peak of monthly rangeland production was in June and was the same for most species. The average rangelands production at the four-year study was about 650 kg/ha, and the contribution of three species Festuca ovina, Bromus tomentellus, and Tanacetum polycephalum were 24%, 20%, and 11%, respectively. The highest forage consumption was recorded in July and then in August. On average, about 71% of forage production was consumed during the grazing season. The lowest and the highest forage consumption was observed for Phlomis olivier  (37%) and Silene ampullata (100%), respectively.