The Productivity of a Festuca/Agrostis Alluvial Grassland at 1700 Ft in the Northern Pennines

A seasonal herbage dry‐matter yield of 2400 lb/acre was obtained on a soil which by chemical analysis was infertile. Fertilizer treatment doubled yield. Monthly cuttings more than halved the yield but increased the mineral content. The highest levels of ash (8·04%) and nitrogen (3·75%) were obtained on the unfertilized sward in August, under the combined effect of sheep grazing and monthly clipping. Phosphorus levels were very low: 0·002% in the soil and 0·11% (August) in the grazed sward. The effect of varying cutting regimes and of a fertilizer treatment in the first year on yields over 4 years was measured. Little difference was detectable in the final year. Variability in the mineral content was found during the season. The August levels, under enclosure, on a dry‐weight basis, were: ash 5·58%, calcium 0·45%, nitrogen 2·05%, phosphorus 0·13%, potash 1·75%, sodium 0·04% and magnesium 0·09%.