Variation in the Growth Potential in a Timothy and Red Clover Mixture

Abstract

Abstract Growth potentials (Rs) in leys at five sites in northern Sweden were determined by using a growth model. The Rs value is independent of the current weather, and is related to stand vigour and depends on the growth cycle, species, age of the ley, soil fertility and winter survival. Timothy (Phleum pratense L.) and a mixture of red clover (Trifolium pratense L.) and timothy at different nitrogen fertilizations were investigated. In the spring growth the Rs value was higher in the red clover mixture than in timothy and lower in the first- than in the second-year leys. In the regrowth the Rs value was considerably higher (25%) in the first- than in the second-year leys. Higher Rs values occurred at sites with higher contents of humus than at sites with lower humus content. Interpretation of results from field experiments could be improved by determination of the growth potential (Rs).