A comparison of soil properties under organic and conventional farming in Australia

Summary

Organic farming is an alternative to conventional farming for providing sustainable crops with high export demand. This review analyses research findings on organic farming in Australia, with an emphasis on soil health. Several reports have indicated that organic farm management generally improves soil physical properties in Australia and elsewhere. Although low nitrogen (N) availability can constrain yields, organic farmers can improve N supply through legume green manures. Plant available phosphorus (P) is a more serious limiting factor in organic farming, particularly in Australia with naturally low P levels. Phosphorus is less easily replaced in the soil than N, and there is a need for alternate sources of organic-certified P and methods to enhance P availability from existing inputs such as rock phosphate. The role of micro-organisms in improving soil health nutrient availability is discussed, as well as the use of P accumulator crops such as Acacia and Tithonia, which could be incorporated as border crops or green leaf manure.