Some aspects of the nitrogen and phosphorus nutrition of tomatoes in a red loam

Abstract

The effect of nitrogen and phosphorus as basal and side-dressing fertilizers on the growth and yield of tomatoes has been investigated at the Redlands Horticultural Research Station in south-eastern Queensland.
Tomatoes gave a consistent yield response to basal applications of both nitrogen and phosphorus, while side-dressings of these elements were without effect.
A study of movement of nitrogen and phosphorus revealed that nitrate was rapidly leached to a depth of 4-6 ft under the existing cultural practices, while little movement of phosphorus was evident.
Evidence is presented suggesting that poor fruit set in colder months is associated with a higher phosphorus requirement during that period.
The results emphasize the need to examine further the methods for assessing available phosphorus in red loams.