Organic vegetable farms are not nutritionally disadvantaged compared with adjacent conventional or integrated vegetable farms in Eastern Australia

Abstract

The soil nutrient status (0–10 cm) of two farming systems (organic (OF) and conventional or integrated (CF) vegetable farms) at three locations (Gatton, Stanthorpe and Dorrigo) was examined for the suite of fertility indicators. A wide range chemical parameters and microbial biomass carbon were similar between farming systems, in contrast to some broad-acre organic systems. Examination of farm management records revealed substantial overlap between nutrient inputs at all localities with CF systems also receiving organic inputs, e.g. green manure and composts. Labile soil phosphorus levels were high (>100 mg kgˉ¹) in both farming systems, at all sites. The nutrient levels of these intensive vegetable production systems revealed potential environmental risks especially in sandy well drained soils and should be monitored accordingly. Future research could be focused on crop management measures to mitigate runoff and deep drainage loss of nutrients from these farms.