Chemical evaluation of vegetables grown with conventional or organic amendments

Summary

This 1976 field trial compared garden vegetables (tomatoes, potatoes, peppers, lettuce, onions, peas) grown with organic or commercial fertiliser amendments under otherwise identical agronomic conditions. Conventional plots yielded more produce, but mineral content and ascorbic acid levels were essentially equivalent between the two fertilisation regimes; trained taste panel assessments showed no consistent preference. The authors concluded both production methods were equal in quality, with only marginal yield differences despite greater seasonal variation.

Regional applicability

This study was conducted in the United States and employed controlled plot conditions typical of temperate vegetable production. The findings are broadly applicable to United Kingdom horticulture given similar climatic and agronomic contexts, though soil type, cultivar choice, and local management practices may influence whether the observed equivalence in mineral content and quality between organic and conventional systems would replicate under current UK conditions.

Key measures

Vegetable yield; nitrogen, phosphorus, potassium, calcium and magnesium content in leaf tissue and edible produce; ascorbic acid concentration; trained sensory panel palatability assessment

Outcomes reported

The study compared yield, mineral content (N, P, K, Ca, Mg), ascorbic acid concentration, and organoleptic quality of six vegetable crops grown under organic or conventional fertiliser regimes over two seasons. Conventional plots produced higher yields, but mineral composition and taste preferences did not differ consistently between production methods.

Topic tags