best available technologies for manure treatment - Baltic Green Belt

Best Available Technologies for manure treatment baltic sea 2020
1: INTRODUCTION AND BACKGROUND DESCRIPTION
plant nutrients in slurry from production pigs is a bit
better in balance with the needs of the crops than the
case is for slurry from sow production. However, in
all cases, whether a limit of 170 or 140 kg N per ha
is used as a limit for fertilising with livestock manure,
the spreading of P on the fields is above the P norms
for a typical crop rotation on a pig farm.
It should be noted in connection to the Table 1
and Table 4 that winter wheat is the most commonly
grown crop on pig production farms in Denmark
(Weznæs et al., 2009) and probably in the entire
Baltic Sea Region (BSR). Fertiliser norms for grass is
also shown in Table 1, although this is not a common
crop on pig production farms – however, grass
is basically a protein crop, therefore requiring a high
N fertilisation, and being the reason for derogations
admitted cattle farms in Denmark and Holland to
the general rule of maximally 170 kg N per ha from
livestock manure.
According HELCOM Convention, Annex III
section 2.1, “The maximum number of animals
should be determined with consideration taken to
the need to balance between the amount of P and
N in manure and the crops’ requirements for plant
nutrients.” It decides for Contracting Parties that
“The amount of livestock manure applied to the land
each year including by the animals themselves should
not exceed the amount of manure containing 170 kg/
ha nitrogen and 25 kg/ha phosphorus with a view to
avoiding nutrient surplus, taking soil characteristics,
agricultural practices and crop types into account.”
Four of the eight target countries have consequently
introduced official P norms for fertilising:
In Sweden and in Lithuania the norms have been set
as a general limit without respect to the actual crop
grown. The limit in Sweden is 22 kg P per ha, and
similarly 40 kg P2O5 in Lithuania. German farmers
are restricted by a P balance of 20 kg P2O5 per ha
(Foged, 2008). Denmark has introduced a maximal
allowed spreading of 140 kg N in livestock manure
per ha, but as seen from Table 4, this is not a sufficiently
low rate to avoid over-fertilisation with P;
Danish installations for the intensive rearing of pigs
typically maximise their production up to the 140 kg
N per ha limit. In Finland the P limits are based on
crops grown and the soil P content. If only manure is
used as P-fertilizer about 18 kg of manure total P can
be spread for grain crops (if the soil P content is not
very high).
Annex L includes statistics about the pig production
in Denmark, Poland and Sweden, as well as
maps with the geographical placement of pig farms
in Denmark and the installations for the intensive
rearing of pigs in Poland.
Animal type
Number of animals that can be
contained within 1 ha of winter
wheat according norms in Table 1
Kg P spread per ha per year, if the
limit for N fertilisation in livestock
manure is fully utilised
N
P
170 kg N per as
limit
140 kg N per ha
as limit
Total for a sow in one year
with production of 26
piglets of 32 kg
5,1 2,2 47,43 38,75
10 production pigs
produced, 32 to 107 kg,
fully slotted floors
64,4 37,7 34,12 28,11
Table 4: Number of sows or production pigs that produces N and P equivalent to the consumption of one ha
winter wheat – by comparison of Table 1 and Table 3, and amount of P spread if the allowed spreading of N
is the limiting factor.
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