Long-Term Effects of Fertilization and Subclover Seeding on Northern California Annual Range

The long-term effects of P and S fertilizers and subclover seeding on northern California annual range production and composition were measured during a 20-year study. Following an initial calibration period, two pastures were seeded and fertilized; pasture A prior to the 1968 growing season and pasture B prior to the 1973 growing season. After treatment pasture A produced significantly more forage annually. It also produced significantly more winter forage, and winter and annual forage N than either of two adjacent untreated control pastures during the period from 1973 to 1979. This was due primarily to an increase in native legumes because subclover averaged only 7% of cover. Treatment on pasture B gave similar responses, but the relative increases in forage production were larger (annual production increased about 2,000 kg/ha compared to 1,200 kg/ha on pasture A), and winter forage N concentrations were significantly higher than on pasture A. This was due to the greater subclover component (36%) on pasture B. The significant increases in forage production and protein indicate that subclover seeding and appropriate fertilization are practical ways of improving utilization of northern California annual range.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.Migrated from OJS platform August 202