DEAR SIR:

While the Irish Farmers Journal’s coverage of organic farming is greatly welcomed, your recent summary of the manuscript “The environmental costs and benefits of high-yield farming” by Balmford et al, published in “Nature Sustainability” on 17 Sep 2018 (“More intensively farmed food has lower environmental impact – study”) stating that “when based on a unit of food produced, the environmental impact of conventional farming was lower than organic” is misleading because you failed to highlight several study limitations.

First, the conclusion was based on a worrying lack of data ensuing from a non-systematic literature review and expert opinion which is weak evidence. Notably, the authors failed to cite the studies utilised making it impossible to check the reliability of results. Furthermore, the beef sector conclusions are based on data from Latin America so we must question its relevance to the Irish organic sector and Latin American organic beef systems are neither described nor defined. Out of five costs investigated (greenhouse gas (GHG) emissions, water use, nitrogen, phosphorus, and soil losses), the authors only obtained data on GHG emissions for the beef sector which tells only part of the environmental story. Finally, surely sustainable, efficient livestock production with high biodiversity should also include good animal welfare, soil health and the human impact of pesticide exposure, all overlooked in the current study.