The foundation of organic farming is a microbially active soil enriched with organic matter and a balanced mineral diet. Humus building practices not only supply plant nutrients, but increases tolerance to insects and diseases, helps control weeds, retains soil moisture, and ensures produce quality. A field experiment was conducted in Shiravan, Iran, during 2005 in order to demonstrate the effects of organic amendments, synthetic fertilizers and compost extracts on crop health, productivity and storability of commonly used tomato (Lycopersicon esculentum Mill.). Treatments included different fertilizers of cattle, sheep and poultry manures, house-hold compost and chemical fertilizers, five aqueous extracts from cattle manure, poultry manures, green-waste and house-hold composts and water as control. The effect of fertilizer type on tomato yield and marketable yield was significant (P<0.05). Poultry and cattle manures and house-hold compost caused higher yields compared to control and chemical treatments. However, marketable yield 6 weeks after storing was highest in poultry manures and lowest in chemical fertilizers. The effect of aqueous extracts was not significant on either crop health or tomato yield and storability.

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