Background

Less fertilizer input under conditions of reduced or more variable water availability

European agriculture is challenged by the need to produce more crops with fewer inputs of fertilizers, especially nitrogen (N) and phosphorus (P), under conditions of reduced or more variable water availability.

Projected climate changes indicate a higher variability in rainfall in the coming decades, with an increased risk of water shortage during summers, while water resources for irrigation will be at best maintained. N and P flows exceed the so-called planetary boundaries, the losses of N and P from various sources including fertilizers being clearly responsible for major impacts on the environment (e.g. eutrophication of surface waters, emission of greenhouse gases such as N2O) in regions of intensive agriculture in Europe.

In addition, phosphate rocks have been included in the list of 20 critical raw materials by the European Commission in 2014, which further pledges to reduce the use of P fertilizers significantly in the future. Meanwhile, socio-economic projections suggest a steady increase and volatility of fertilizers' prices.

Sustainable or ecological intensification of agroecosystems needs to be implemented by combining novel crop varieties and management approaches that make better use of below-ground biodiversity and processes to sustain high levels of productivity with reduced use of water and nutrient resources. There are different pathways to move towards biodiversity-based agriculture, and they largely depend on the farming systems (e.g. level of intensification, following conventional, organic or conservation agriculture principles) and regional context (e.g. specialized cereal-based agriculture or integrated crop and livestock production).