Effects of Bentonite Clay-Starch Coated Urea Fertilizer Rates on Tomato (Solanum lycoperiscum) Growth and Yield in Mekelle, Tigray, Ethiopia

Abstract

. N loss from applied urea fertilizer in the soil is a major challenge due to its high volatile behavior, high leaching, low usage efficiency, excessive solubility rate. In this study, a field experiment was conducted in order to investigate the effects of different rates of coated urea fertilizer with bentonite clay-starch on growth and yield of tomato. The experiment was laid out in a Randomized Complete Block Design (RCBD). Treatments consisted four different nitrogen levels (0, 40, 80, 120 kgha-1) using coated and uncoated urea fertilizers replicated four times. Data on plant height, number of primary branches per plant, number of leaves per plants, fruit diameter, number of fruits cluster per plant, weight of single fruit and fruit yield were collected from five plants which were randomly selected from the middle rows of each plot, and the data were made to statistical analysis significance of treatments and comparison of treatment means. The statistical analysis showed that was a significant (P<0.05) difference among treatments for all parameters. The application of 40 kgha-1coated nitrogen fertilizer provided 31.9, 27.9 and 74.1%% increment of plant height, number of leaves and number of primary branches, respectively over the control treatment. Furthermore, application of 40 kg ha-1 coated nitrogen fertilizer increased the number of fruit cluster per plant and yield of tomato fruit per hectare by 124.1 and 60% over the control treatment, respectively. However, tomato yield was at parity between 40N kgha-1 coated and 120 kg N ha-1 uncoated urea per hectare. Coated urea having 40 kg N ha-1 had the highest NUE (1,645.3). Results indicated that the application of bentonite clay-starch coated urea fertilizers significantly improved plant growth, yield, and nitrogen use efficiency compared to uncoated urea. Economic analysis, showed that coated urea having 40 kg N ha-1 highest profitability. Therefore, farmers should use 40 kg N ha-1 coated urea fertilizers, as these levels have shown significant improvements in tomato yield and profitability.