| On Topic
Compost tea
Field lab
sees yield increases
from compost teas on
organic arable farm
The pioneering farmer-led network Innovative Farmers has released initial results from
research into the large-scale application of compost teas in agriculture.
ut of the three farms involved in the
field lab, one farmer has seen yields
increase 35-50% on the fields tested
in the first year of application, and all
farms have seen increases in soil
fungi. Compost tea was sprayed on
45 hectares of test areas three times during the field
lab, from April to June, and fields ranged from peat
soil to calcium dominated soil.
Sophie Alexander of Hemsworth Farm said that
while these initial results are promising – more
research is definitely needed. The team at
Hemsworth are committed to using and testing
compost teas again this year to find out more about
their effect. The initial trials were not replicated within
fields, but were carried out on four different sites.
The Innovative Farmers field lab began in March
2014, linking a group of farmers including organic and
non-organic arable farmers from across England, and
one apple grower, with researchers from the Organic
Research Centre.
Liz Bowles, head of farming at the Soil Association,
O
10 | Farming Monthly | April 2016
is co-ordinating the group. She said; “The results of
the compost tea field lab are very positive at one of
the farms but we now need to repeat and extend the
trials. Innovative Farmers helps farmers carry out
more reliable trials at scale – in this field lab we have 3
farms and 45 hectares involved in the trial. By testing
compost teas on different farms, with different soils,
we can find out more about the effects that compost
teas can have on soil microbiology.”
An estimate of the cost benefit of using compost
teas suggests that for the first 10% increase in yield
on an organic farm, the financial benefit from use of
compost teas after costs was around £18/ha. For
every further increase of 10% in yield, the additional
benefit was estimated to be around £70/ha. Increases
in yield at the three trial sites ranged from 10% to
around 50%.
At all trial sites increases in active fungi, flagellates
and amoebae were significant (full report available to
Innovative Farmers members here). The presence of
active fungi is essential for effective nitrogen and
phosphorous absorption in crops. Fungi are one type
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