Fertilizer requirements of potato in the presence of farmyard manure at Shillong

A two year field study, on an acid soil of Shillong, showed a highly significant response of potato (Solanum tuberosum Linn.) to 120 kg N/ha and 17.5 kg P/ha in the presence of a basal dose of farmyard manure (20 t/ha). The best combination of N and P (120 kg N+17.5 kg P/ha) equalled 100 kg N+70 kg P+50 kg K/ha in tuber characters, yield of different grades of produce, aggregate yield and uptake of N, P and K. However, for the number and yield of medium sized potatoes, 60 kg N—17.5 kg P/ha was an adequate dose.