Effects of Organic and Inorganic Fertilizers Applications Levels on Greenhouse Tomato (Solanum lycopersicum) Yield and Soil Quality in Khost Province

The study was carried out to determine the effect of organic and inorganic fertilizers on tomato yield and soil quality. The study was performed in a randomized complete block design consisting of 7 treatments with 3 replications in the research farm, Shaikh Zayed University, Khost, Afghanistan. The fertilizers treatments were T1, organic fertilizer (5 t/ha); T2, organic fertilizer (10 t/ha); T3, urea (150 Kg/ha); T4, urea (200 Kg/ha); T5, mixed fertilizers (organic fertilizer 3 t/ha + urea (100 Kg/ha); T6, mixed fertilizers (organic fertilizer 6 t/ha + urea (70 Kg/ha) and T7 a control. Results indicate that applications of inorganic fertilizers with a combination of organic fertilizers increased tomato yield and improves the nutrient status of the soil. T5 showed the highest yield of tomato and followed by T4 treatment, which were 33.1 and 31.7 t/ha respectively. The lower yield were obtained in T7 and T1 treatments. The highest plant heights (205.0 and 199.0 cm) were obtained in T5 and T4 respectively, while the lowest plant heights were obtained in T1 treatment and followed by T7 treatment. Similarly, we found that a combination of both inorganic and organic fertilizers application also is the best strategy to improve soil nutrients, maintain soil fertility. Soil P2O5 and K2O, where the highest amounts were obtained in T5 and followed by T6, which were 26.5, 22.5 and 44.5 and 41.5 mg/L respectively. The control treatment had the lowest amount of P2O5 and K2O. Therefore, this study suggests that an appropriate amount of organic fertilizer with inorganic fertilizer not only increased tomato yield but also improve soil fertility.