Fertigation scheduling in tomato based on the hydraulics and nutrients under point source of water application

Drip irrigation with fertigation is the most efficient way to supply water and nutrients to the plant as it saves significant amounts of water and nutrients and enhances the quality and quantity of vegetable and fruit crops. The effect of soil moisture movement and nutrient dynamics on the growth and yield of tomato was studied. Tomato (Indo-American hybrid var. Rashmi) crop was transplanted and the movement of waterfront and the distribution of soil moisture and nutrients (N, P2O5 and K2O) in soil under alternate day, weekly, fortnightly and monthly fertigation frequency were monitored. Lateral pipe having drippers of 4.0 l h-1 discharge at a distance of 40 cm was used for applying water. Tomato is 180 days duration crop and is divided in four stages namely, initial (35 days), developmental (45 days), middle (70 days) and late stage (30 days). The water requirement of tomato varied from 2.1 to 7.0 l day-1 m-2 from early stage to peak demand period. The total amount of water needed to irrigate 1.0 ha of tomato crop was estimated as 66.4 cm. To meet the nutritional requirement of tomato crop, 50 t ha-1 farm yard manure, 180 kg ha-1 nitrogen (N), 230 kg ha-1 phosphorous (P2O5) and 190 kg ha-1 potassium (K2O) were applied. NO3-N, NH4-N, P2O5 and K2O concentration around the point of application (at 0.0 cm from lateral pipe) were found more than at 15 and 45 cm away from lateral pipe throughout the crop season. The maximum NO3-N, NH4-N, K2O and P2O5 concentration was found in upper soil profile. Crop quality and yield of tomato crop was improved by fertigation significantly. The maximum yield of 96.2 t ha-1 was observed under alternate day fertigation and the minimum yield of 72.5 t ha-1 under treatment monthly fertigation. The comparison among the four treatments showed that the adoption of alternate day or weekly fertigation was more profitable as compared to the fortnightly and monthly fertigation.