The yield and soil data are presented of four long-term experiments on sugarcane at Muzaffarnagar (Uttar Pradesh), Anakapalle (Andhra Pradesh), Padegaon (Maharashtra) and Shahjahanpur (Uttar Pradesh). On soils where phosphorus and potash were not limiting, application of ammonium sulphate over 14 years at Muzaffarnagar and Anakapalle gave higher yields than those obtained by application of farmyard manure, and the fertility status of ammonium sulphate plots was in no way inferior to plots treated with farmyard manure. When phosphorus was also limiting, the application of a basal dose of compost on black cotton soil maintained yield levels. There was a steady decline in yields of cane in plots which received a dressing of ammonium sulphate without any basal dose of compost, but when N.P.K. equivalent to the compost were added the yields were equal to those from plots receiving compost. Thus the effect of compost is explanable on its nutrient content rather than on its effect on physical properties of the soil. In Shahjahanpur there was a decrease in cane yield as the experiment progressed, but the decline in yield in ammonium sulphate treated plots was of the same magnitude as from the plots receiving no dressing of ammonium sulphate. By changing the cane variety and the rotation simultaneously, the yield from all plots went up but subsequently showed a declining tendency.