Sustainable growth of organic farming in the EU requires a rethink of nutrient supply

Summary

The European Commission recently set
a target of increasing the area of organic agriculture
to 25% by 2030. To achieve this, it is imperative to
understand current nutrient use patterns and identify
sustainable nutrient supply opportunities. To that end,
this study assessed the sustainability of the current
nutrient origin and supply of 71 arable organic farms
in 8 European regions. Defcient nutrient supply was
found on 24%, 66%, and 56% of farms for nitrogen,
phosphorus, and potassium, respectively. On average,
we show a moderate surplus for nitrogen (28 kg ha−1),
while phosphorus and potassium balances were close
to zero (−1 and 2 kg ha−1, respectively). Large variation between countries and farm types shows a divide
between more intensive systems relying on external
inputs, and less intensive systems facing nutrient defcits and lower outputs. We show, for the frst time, the
extent of current use of external input types, where
conventional manures supplied 17–26% of external
nutrients and inputs from non-agricultural origin supplied 31–41%. A large proportion of nutrient sources
within the last group are materials derived from urban wastes. The sustainable expansion of the organic
sector will require increased use of locally available
recycled fertilizers from urban wastes, and acceptance of such sources by organic farmers is shown to
be high, provided they are considered safe.