Effect of nitrogen, phosphorus and potassium on yields and nutrient levels in celery and head lettuce grown on sphagnum peat.

Celery and head lettuce were grown on sphagnum peat with fertilizer treatments consisting of an N, a P and a K series. Each nutrient was applied at four rates in combination with constant rates of the other two. Results indicated that N requirements of the two crops were similar but that celery required higher rates of P and K than lettuce. For the latter crop N, P and K at approximately 180, 40 and 150 kg/ha respectively appeared adequate, whereas the P and K requirements of celery were 80 and at least 225 kg/ha respectively.