Received: 20-03-2017 / Accepted: 03-05-2017
This experiment was conducted during 2015 winter in neutral to slight acidic alluvial soils of the Red River delta in Gia Lam district of Hanoi. A mathematical model was appliedr determine drip irrigation regime for obtaining highest yield and water use efficiency of winter tomato. The functions determining soil moisture in mathematical model were tested and the difference with real data was less than 8%. In the case of soil moisture at 70-100% the maximum field capacity, the mathematical model predicted 11 irrigation times per season with the drip irrigated area (ahn= 52.3%) varied between 198.7 - 201.4 m3/ha/irrigation. The amount of water, taking into account the proportion of drip irrigation area (ahn= 52.3%), ranged between 198.7 - 201.4 m3/ha/irrigation. The water use efficiency was of 30.5 kg/m3, increased by 16.2 kg/m3 and water irrigation amount was saved by 42.8% compared to furrow irrigation. Drip irrigation regime was proposed for winter tomato as follows: number of irrigation for whole cropping season was 10, irrigation water amount was 198.7 m3/ha for each application (equivalent to 6.2 liters/plant/irrigation), total irrigation water amount in a cropping season was 1987 m3/ha.