The Effects of N and K Fertigation and Drip Irrigation with Traditional Fertilization on Tomato Yield and Quality.

In order to monitor the advantages of fertigation over traditional fertilizers application with drip irrigation on tomato yield, quality, and Water Use Efficiency (WUE), an experiment was conducted for two seasons at the experimental station of the Arab Center for the Studies of Arid Zones and Dry Lands (ACSAD) in Deir Al-Zoor province (Syria). The station is located on 40◦ 11′ E and 25◦ 22′ N at an elevation of 203 m ASL. The experimental design of both experiments was RCBD with three replicates using drip irrigation system with two treatments namely Fertigation (F) and Drip irrigation with Traditional Fertilizer application (DTF). The soil classified as mixed thermic torrifluvent with clay texture between 20 and 40 cm depth and clay loam texture in other depths. A layer containing gypsum appears about 120 cm below the soil surface. Drainage tiles installed at 140 cm depth with spacing of 40 m. The chemical analysis shows that the soil is slightly saline and slightly alkaline. Soil and plant analysis performed to monitor soil fertility status, yield quality in addition to yield and WUE of tomato grown during 2009 and 2010 seasons.Tomato fertigation treatment (66.81 T.ha-1) significantly over yielded (DTF) treatment (57.76 T.ha -1) with LSD0.05 = 8.63 T.ha-1, and (WUE) values were 4.43 and 3.78 Kg.m-3 for (F) and (DTF) treatments respectively. Tomato juice acidity values with pH meter was 3.8 and 3.9 for F and DTF respectively and average Brix values under F treatment 5.48 was higher than that of DTF values 5.16.Yield of the F treatment decreased a little during the second growing season to end up with no significant differences between the two treatments. Where the yield of (F) treatment decreased about 2% to become 55.54 T.ha -1 and the yield of (DTF) increased about 2% to end up with 58.34 T.ha -1. A reduction in soil fertility observed by the end of the two growing seasons, which is an indication of the underestimation of NPK fertilizers application recommendation of Ministry of Agriculture / Syria for the experimental site.