WATER AND FERTILIZER REQUIREMENTS FOR TOMATO CROP UNDER TRICKLE AND SPRINKLER IRRIGATION SYSTEMS IN SANDY SOILS

Field experiments were conducted during the growing season of 2006 at the Desert Farm of the Faculty of Agriculture, Ain Shams University, ELBustan Region, Beheira Governorate that presents sandy soil conditions, to determine the water and fertilizer requirements for tomato crop. Tomato transplanting (Castle Rock variety) was planted under trickle and sprinkler irrigation systems. Also, nitrogen fertilizers (Ammonium nitrate, 33%N) were applied through trickle and sprinkler irrigation systems with three rates (50, 75 and 100 kg-N/fed). The results of this experiment revealed that 1- Irrigation efficiency under trickle irrigation (84.16%) was higher than that under sprinkler irrigation system (66.32%) by 17.84%. 2- Seasonal irrigation water requirements for tomato crop based on the climatic data (2439.9 and 2832.8 m3/fed) was higher than estimated values using the soil samples method (1886 and 2153.1 m3/fed) by 16.1% and 14.1% under both trickle and sprinkler irrigation systems respectively. 3- Highest yield was obtained (8.61 ton/fed) when using trickle irrigation compared to sprinkler irrigation (7.10 ton/fed) by an increase of 21.2%. 4- Water use efficiency under surface trickle irrigation was (3.53 kg/m3) higher than that under sprinkler irrigation systems (2.51 kg/m3) by 40.6%. 5- There was no significant effect to irrigation method on the plant height, and number of branches/ plant, but there was an effect to irrigation method on No. of fruits/plant. 6- Tomato yield increased by 202% and 172% with increasing fertilization rate from 50 to 100 kg- N/fed under both trickle and sprinkler irrigation systems respectively. 7- The lowest cost of tomato production unit was 89.3 and 104 LE/ton under trickle and sprinkler irrigation systems respectively at fertilization rate of 100 kg-N/fed, while the highest cost of tomato production unit was 231.3 and 222.3 LE/ton under sprinkler and trickle irrigation systems at fertilization rate of 50 kg-N/fed. 8- The difference in the cost of tomato production unit, when applying 75 and 100 kg-N/fed with trickle irrigation system, was small.