Nutrient Interactions and Deficiency Diagnosis in the Lettuce III. Nitrogen Content and Response to Nitrogen

Lettuce plants grown in sand culture, and receiving nitrogen, phosphorus, and potassium at five levels in all combinations, were analysed at different stages of growth for total, soluble, and nitrate nitrogen. An attempt was made to relate these analytical data to the subsequent response (in dry matter production) shown by the plants when a further amount of nitrogen was supplied.