The Effect of Slow Release N Fertilizer on Some Soil Properties and Growth of Tomato Seedling

Abstract

The study aimed to determine the effects of slow release N fertilizer on soil properties and the growth of tomato seedlings. The experiment was carried out in a greenhouse as 2x4 factorial in completely randomized design with 4 replications. The first factor was the kind of fertilizer (slow release N fertilizer and urea), and the second factor was the amount of fertilizer (5, 10, 15 and 20 g N/plant). The results revealed that the soil NH+4-N of urea treatment tended to decrease gradually, but that of Floranid treatment tended to increase with time until 40 days after planting, after which it appeared to have constant level. The soil NO-3-N from urea treatment decreased at 20 and 40 days after planting, but tended to increase after that. On the contrary, the soil NO-3-N from Floranid treatment had a gradual increase up to 40 days, but then decreased slightly. Increasing fertilizer levels reduced soil pH but increased EC value. Urea application induced lower pH but higher EC that those of Floranid. The number of leaves, P and K contents in the stem and root, and the ratio of root N:shoot N were not significant (P>0.05). Floranid application at 10 g N/plant induced the highest stem fresh weight and stem dry weight at 46.78 and 9.71 g/plant, respectively. The lowest stem fresh and dry weights of 27.75 and 6.72 g/plant, respectively, were found in 20 g N/plant of urea treatment. The highest fresh and root dry weights, 10.73 and 1.44 g/plant, respectively, were found in 5 g N/plant of Floranid treatment. The treatment of 20 g N/plant of urea gave the lowest root fresh and dry weights of 3.40 and 0.58 g/plant, respectively. Urea application induced the tomato seedlings to gain lower plant fresh and dry weights than those of Floranid.