Background and methodology
Processing tomato is the major vegetable crop produced in California that typically relies on inputs of mineral fertilizers and other agricultural chemicals, irrigation and relatively intensive tillage. During the last decade, political, economic and resource based pressures on farmers have increased and many growers are considering changing from conventional to low input or organic farming. Organic vegetables are usually considered by the consumer to be more nutritious and safer products than conventionally grown vegetables. Several studies have however reported inconsistent results in terms of fruit nutritive value, organoleptic quality and productivity between organic and conventional production systems. This study evaluated the influence of established organic, low input and conventional farming system on soil chemical properties, processing tomato yields and fruit mineral composition. The influence of 10 years of organic low input and conventional management practices on soil chemical properties, processing tomato yields and fruit mineral composition was evaluated.
The organic system had highest soil total C, N, soluble P, exchangeable Ca and K levels as a result of 10 years of manure application and cover crop use. Organic fruits contained highest amounts of P and Ca. Conventionally grown tomatoes were richer in N and Na
Colla, G., Mitchell, J. P., Poudel, D. D. & Temple, S, R. (2002). Changes of tomato yield and fruit elemental composition in conventional, low input and organic systems. Journal of Sustainable Agriculture 20(2):53-67