Nitrate content of vegetables commercially grown on land subject to inorganic or organic fertiliser

Abstract

A relatively quick and simple spectrophotometric method of measuring nitrate concentrations in vegetables has been used incorporating a Cu−Zn couple to provide a nitrate-free reference sample. This technique has been used in a preliminary study of the nitrate content of carrots and cabbages commercially grown on soils treated with either inorganic or organic fertiliser and available through normal retail outlets. Although it cannot be concluded that the nitrate levels in the organically fertilised vegetables were lower than those grown using conventional inorganic fertiliser, it can be concluded that the precise conditions of cultivation and soil do affect the nitrate levels in carrots and cabbages grown commercially.