Integrated Effects of Vermicompost and Nitrogen on Yield and Yield Components of Tomato ( Lycopersicum esculentum L.) in Lowlands of Eastern Harerghe

Organic fertilizers improve the soil texture, structures, aeration and allow it to hold water longer, and increase the bacterial and fungal activity in the soil. So, they not only assist your plants, they help the soil. Increasing the use of organic fertilizers and minimizing the use of chemical fertilizers lead to sustainable production of food for human being. Shifting crop production to the use of organic fertilizers can minimize the cost of purchasing chemical fertilizers. Insufficient amount of nutrients in the soil is also among the main factors which constrained productivity of the tomato. Due to this gap the experiment was conducted in Sofi district, Harari People Regional State, Ethiopia in 2016 and 2017 cropping season to investigate the effect of vermicompost and nitrogen rate on yield and yield components of tomato. Experimental treatments were vermicompost rate (0, 1.4, 2.8 and 4.2 t ha-1) and nitrogen rate (0, 50, 100 and 150 kg ha-1). A total of 16 treatments were laid out in Randomized Complete Block Design (RCBD) in factorial arrangement with three replications. Melkashola Variety was used for the experiment. The result showed that plant height was significantly (P<0.05) influenced by the application of vermicompost while number of branches, number of clusters, number of fruits, average fruit weight and fruit yield were significantly (P<0.05) affected due to the interaction effect of vermicompost and nitrogen.. The highest plant height was rerecorded at 2.8 t ha-1 of vermicompost whereas the lowest was for the rest rates. Maximum number of clusters, number of fruits and fruit yield were obtained at combined application of 2.8 t ha-1 of vermicompost with 100 kg ha-1 N while maximum number of branches and average fruit weight were recorded at 2.8 t ha-1 with 150 kg ha-1 N and 4.2 t ha-1 with 50 kg ha-1 N respectively. Maximum economic return (461,606 birr ha-1) was also recorded at 2.8 t ha-1 and 100 kg ha-1 vermicompost and nitrogen, respectively with acceptable marginal rate of return. In general, the combination of vermicompost and nitrogen at 2.8 t ha-1 and 100 kg ha-1 was the best combination for the study area.