The challenge of achieving a sustainable crop nutrient supply throughout the world– 33rd Francis New Memorial Lecture

The primary requirement for sustainable agriculture at the farm level is economic viability: it must be profitable. Provided this is met, other requirements for sustainability include a cropping system that suits the local topography and climate, does not damage the environment but rather enhances it and has a sustainable nutrient supply. For any farm exporting produce, the nutrients in that produce must be replaced if the soil is not to be depleted, causing productivity to slowly decline. Currently fertilisers, especially nitrogen, are estimated to provide the nutrients to produce the food for half the world’s population. However the global population is predicted to increase to perhaps 10 billion and global food demand by 60% by 2050, and 9% of the world population – around 697 million people – are currently classed as severely food insecure.

Whilst the need to balance nutrient exports with a sustainable nutrient supply is generally understood in the developed economies, research continues to show it to be an issue on a global scale, especially in Sub-Saharan Africa, but with specific problems in the developed world of both excess and deficiency. The paper will discuss the problem of achieving a sustainable nutrient supply to feed the increasing global population using data on soil analysis and nutrient budgets from the UK, Europe and beyond and the importance and continuing need for fertilisers.