Nitrogen Metabolism and Tomato Yield in Response to Organic Fertilization

We assessed the effects of organic fertilization on the response of biochemical and physiological indicators and the yield of saladette-type tomato (Solanum lycopersicum L.) grown under greenhouse conditions. Five fertilization forms [sand + inorganic nutrient solution (F1); sand + vermicompost tea (F2); a mixture of sand, compost, + vermicompost tea (F3); a mixture of sand, vermicompost, + vermicompost tea (F4); and a mixture of sand, compost, vermicompost, + vermicompost (F5)] and two genotypes (Cuauhtemoc and El Cid) were evaluated. The parameters analyzed were leaf pigments, enzymatic activity of nitrate reductase (NR) in vivo, and yield. A fertilizer source of sand + vermicompost tea resulted in the best assimilation of nitrate (NO3-), the greatest NR endogenous activity, the second highest foliar concentration of organic nitrogen (N), and the second best yield. In conclusion, for improved tomato cultivation during organic production, treatment F2 produced the maximum organic yield and resulted in more efficient N utilization.