Response of grassland to the application of sulphur at two sites in north‐east scotland

The effect of sulphur fertilisation on yield and herbage composition was investigated in two successive years at two grassland sites, one with ryegrass and one with ryegrass/ clover, where the available sulphur in the soil was less than 10 mg kg−1. When supplies of N, P and K were not limiting, herbage yields increased with added sulphur at both sites, particularly at the second and third cuts and in the second year. Sulphur additions also increased the concentrations of total S and SO4−2−S in the crop, and reduced the N:S ratio. The figures for these parameters in herbage from control plots confirmed that low yields in the presence of normal nitrogen fertilisation were probably caused by sulphur deficiency.