The origin and hazard of inputs to crop protection in organic farming systems: are they sustainable?$

Sustainability is de®ned as the ability of a system to `continue'. In view of this de®nition, several aspects of the crop protection activity in organic farming are reviewed according to their ability to `continue'. As no absolute measure of sustainability is available, this analysis takes the form of a comparison between organic and conventional crop protection methods. Two elements of crop protection are considered: one being the source of the inputs to crop protection and the other being the environmental hazard of the chemicals used in crop protection. In addition, the sustainability of some of the wider issues related to crop protection methods in organic farming are discussed. It is concluded that organic farming systems are not sustainable in the strictest sense. Considerable amounts of energy are input to organic farming systems, the majority of the compounds utilised in crop protection are derived from non-renewable sources and incur processing and transport costs prior to application. Further, these compounds are not without toxicological hazards to ecology or humans. Despite these problems, it is concluded that organic farming is probably more sustainable than conventional farming in a bio-physical sense. However, an assessment of the overall sustainability of farming systems may depend upon the valuation given by society to their inputs and outputs, and in this sense it is extremely dicult to assess which farming system is most sustainable. # 2001 Elsevier Science Ltd. All rights reserved.