B. Bar‐Yosef
B. Sagiv
Despite the widespread use of combined trickle irrigation and fertilization (fertigation) in arid zones, little is known about the efficiency of point source fertigation in general, and about drip irrigation management of tomatoes in particular. The objective of the present work was to study the response of tomato plants grown under trickle irrigation in sand dunes to total and daily N application rates, and to concentrations of N in the irrigation water and in the soil solutions at various physiological stages of growth.
The experiments, carried out at three different locations in Israel, included combinations of several daily N and water application rates and two irrigation intervals.
The total yield (Y, in metric tons/ha) was related to total N application rate (X, in kg/ha) by the regression equation Y = 0.0714X + 35.83. The overall N uptake in the high‐yield treatments was about 30% of the N applied. The low efficiency is attributed partly to excessive N application 140 days from seeding, when the daily demand for N (FN) was small. To obtain the optimum FN values at about 70 and 140 days after seeding (5.2 and 2.2 kg N ha−1day−1), NO3‐N concentration in the soil solution should be 200 and 100 ppm, respectively.
