Agriculture Reference
In-Depth Information
Trial description (see Table 2.1
for details)
Physical fertility
Biological fertility
Chemical fertility
Apple production, Washington
State USA
The organic treatment had lower
bulk density than the other
treatments owing to 2 t ha
-1
compost additions and tillage for
weed control. Compared to the
conventional treatment, aggregate
stability was higher in the
integrated and not different in the
organic treatments. Although the
organic treatment received twice as
much compost as the integrated
treatment, the negative effects of
tillage on aggregate stability offset
the benefits of the compost (Glover
et al.
2000).
There was higher microbial
biomass C in organic and
integrated treatments due to
compost additions, but no
differences in biomass N, microbial
respiration or earthworm
populations (Glover
et al.
2000).
There was no difference between
organic and conventional
treatments in total N, nitrate,
extractable P (Glover
et al.
2000)
or leaf tissue nutrient contents
(Reganold
et al.
2001).
Apple production during
conversion, California, USA
At some sampling times, the
organic treatment had lower bulk
density and higher water holding
capacity than the conventional
treatment (Werner 1997).
At some sampling times microbial
biomass C was higher in the
organic treatment than the
conventional treatment.
Mycorrhizal colonisation of roots
was consistently higher in the
organic treatment than the
conventional treatment. There
were no differences between
treatments in earthworm density or
soil-surface arthropod diversity or
abundance (Werner 1997).
There was no significant difference
between treatments in extractable
P (Werner 1997).
