Abstract Two laboratory and greenhouse experiments were carried out to compare and evaluate the nutrition of cowpea plant (Vigna unguiculata L.) by foliar spray and through root media. Effect of four treatments: 1) N nutrition solution, 2) Urban solid waste leachate (USWL), Municipal solid waste compost leachate (MSWCL) and control (distilled water) on germination and seedling growth of cowpea was examined for 10 days under incubation conditions at 20 C. Under greenhouse condition, in addition to four mentioned treatments, municipal solid waste compost extracted paste (MSWCE) + sand was included as the 5th treatment. Foliar spray of all treatments, except, the 5th treatment, was performed daily starting at plant two-leaf stage and continued for one month. The results showed that foliar spray with organic compounds of low concentrations had a positive effect on vegetative growth and plant dry weight. Leaves were thicker, more succulent and dark green in color. Probably, higher photosynthetic activity of plant imposed a positive impact on plant internodes growth, resulting in an increase in leaf dry weight, stem, and plant total dry weight yield. Foliar spray with organic compounds increases the droplet persistence on leaf surface and hence absorption of plant nutrient elements was enhanced. From this study, it is clear that foliar application is not an alternative but only a complementary measure to ensure adequate nutrient supply in addition to root media.

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