To investigate the effect of Zn and Fe nanoparticles, as well as vermicompost and humic acid on the yield and absorption of macronutrients in tomato, a factorial experiment with a randomized complete block design was conducted at Agricultural and Natural Resources Research Center of Torogh. The first factor consisted of organic compounds at three levels of control (non-consumption), application of 5 ton/ha-1 of vermicompost and application of 5 kg/ha-1 of humic acid. The second factor comprised of Fe nanoparticles at two levels of control (non-consumption) and use of 2.6 kg/ha-1 of Fe nano-oxide and the third factor consisted of Zn nanoparticles at two levels of control (non-consumption) and use of 2.6 kg ha-1 of zinc nano-oxide. The samples of each plot was obtained from three central lines by removing one meter from each side. A leaf sample and a fruit sample were derived from each plot and analyzed to determine the concentration of macronutrients. The results showed that the highest N concentration of fruit was observed in control treatments and combined use of humic acid and Zn nanoparticles. The highest P and K concentrations in leaves and fruit yield were observed at different levels of organic compound treatments (including humic acid and vermicompost) and the application of Zn and Fe nanoparticles. The lowest level was also observed in non-consumption of organic compounds and Zn and Fe nanoparticles. In the interaction of organic compounds and Zn nanoparticles, the combined use of humic acid and Zn nanoparticles showed the highest and the combined use of vermicompost and Zn nanoparticles revealed the lowest P concentration in the fruits. The comparison of the mean interactions of organic compounds and Fe nanoparticles, as well as Zn and Fe nanoparticles suggested that except for the treatment of Fe nanoparticles (alone), which was placed at a lower class, other treatments were placed at the same statistical group in terms of P concentration in the fruit. In general, the use of humic acid and vermicompost as sources of organic compounds could contribute to the absorption of macronutrients by plants, increasing P and K concentrations in leaves as well as N and P concentrations in tomato, which enhanced the overall yield of tomatoes.

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