Page 45 - Green knowledge 2024

Photo: Erling Fløistad
Manure is worth its weight in gold
“Farmer’s gold” emits greenhouse gases and pollutes waterways. But it also recycles
nutrients already present in agriculture, making it circular economy at its best. We just
need to know how to use it most efficiently.
Manure contains a variety of nutrients, but not all
are readily available to plants. For decades, research
has looked into nutrient utilisation in manure, yet
scientists believe we still need more knowledge.
“Conditions are changing, so we must constantly
update our knowledge. Farms are getting larger. The
amount of nutrients added to farms via feed concen-
trates and fertiliser is changing. The climate is shift-
ing, with more rainfall and milder winters. Addition-
ally, technology keeps developing. New spreading
methods and manure treatments, such as biogas pro-
duction, are emerging,” explains researcher Åsmund
Kvifte.
losses. Diluting manure with water to help it pene-
trate soil faster or using band spreaders can also
help. Spreading in sunny, windy conditions increases
losses.
The other half of the nitrogen in manure is in organic
molecules, rarely directly available to plants. This
nitrogen can build a reserve in the soil, requiring
microbes to break down the complex molecules.
Microbial activity increases with higher soil tempera-
tures and sufficient moisture. However, excessive
water blocks nutrient release and uptake.
“The better we can utilise manure, the less artificial
fertiliser we need, and the less nitrogen ends up as
pollution instead of plant nourishment,” Kvifte con-
cludes.
In Norwegian agriculture, nitrogen is the most
important nutrient for achieving high yields. Around
half of the nitrogen in manure is inorganic and
directly available to plants, but it can evaporate as
gas. Early spreading can significantly reduce these
Purpose: Contact: A new fertiliser regulation from 2024 sets stricter limits on how much livestock manure farmers can
use each year. Updated knowledge and methods for managing livestock manure are needed.
Research Scientist Åsmund Mikalsen Kvifte, Division of Food Production and Society.
Email: asmund.kvifte@nibio.no | Phone: +47 954 71 247
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