This paper presents results of two N, P, K, S mineral fertilizer trials on wheat (Triticum aestivum L.), carried out at Pindamonhangaba, State of São Paulo, in low land condition, with irrigation, in 1971 and 1972. The responses observed in these trials were large for nitrogen, medium for phosphorus and very small for potassium and sulphur. Every 30 kg N/ha increased 211 kg/ha the production. The effect of complete mineral fertilizer was highly significant. Every 60-60-30 kg/ha of N, P2Os and KzO, respectively, increased 352 kg/ha the production.