OPTIMIZING NITROGEN FERTILIZATION OF VEGETABLE CROPS BY DRIP IRRIGATION
Nitrogen nutrition requirements of lettuce seedlings in recirculating solution culture were investigated. The effects of different NH4-N/ NO3-N ratios on growth of the plants were measured. A growth technique, in which additions of nitrogen increase with time as a result of electrical conductivity and pH titrations was tested. The results obtained showed that a stable internal nutrient status was achieved after 2 weeks. Linear regressions were found between accumulated nitrogen addition and growth, accumulated nitrogen addition and accumulated nitrogen uptake. This information can be employed in establishing conditions for efficient use of N fertilizer in drip irrigation.
Gastaldi, C.R. and Sutton, B.G. (1989). OPTIMIZING NITROGEN FERTILIZATION OF VEGETABLE CROPS BY DRIP IRRIGATION. Acta Hortic. 247, 217-222