Fruit Crop Ecology and Management - UVM Apple Orchard

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Desirable soil quality
Physical and
chemical properties
Additions of organic materials
in the form of crop residues or
amendments such as
composted manure increase
the levels of the resistant and
slow pools. These forms of soil
organic matter are most
responsible for improving the
physical and chemical
properties of the soil.
Enhancing the resistant and
Fruit Crop Ecology and Management: Chapter 1
A high quality soil resists degradation and responds to
management. It has a dynamic belowground food web that
transforms and transports the matter and energy required to
develop and maintain successful fruit plantings.
High quality soil characteristics
• Provides suitable habitat to sustain biological activity, diversity
and productivity.
• Stores, releases and cycles nutrients.
• Regulates water and solute flow without being excessively wet
or dry.
• Provides ecosystem services such as filtering, buffering,
degrading, immobilizing and detoxifying undesirable
materials.
Indicators of soil quality
• Topsoil and rooting zone depth.
• Organic matter levels.
• Size of active and slow carbon and nitrogen pools.
• Biotic diversity (nematode community structure, for example).
• Water-holding capacity, infiltration and bulk density.
• pH and electrical conductivity.
slow pools decreases soil
compaction and erosion of fine
particles. Other benefits are an
increase in plant-available
water, improved water
infiltration and soil aeration,
greater soil aggregate stability,
increased ion exchange
capacity and greater retention
of nutrients. More easily
decomposable organic matter
is also important because
during decomposition
microorganisms excrete gels
and slimes that bind soil
particles together and improve
soil structure.
Biological properties
The active soil organic matter
pool is the main food source for
microorganisms. Practices that
increase this pool build
microbial activity, enhance
nutrient availability and may
lower incidence of soilborne
diseases. Such practices
include planting nitrogen-fixing
legume cover crops, adding
compost or manure, and
reducing tillage. Microorganisms
also feed on root
exudates released from living
plants, so keeping cover crop
roots active for as much of the
year as possible promotes soil
microbial activity. These
practices frequently enhance
soil biological diversity, such as
by increasing beneficial
populations of nematodes.
The role of nematodes
Most fruit growers think of
nematodes as microscopic
worms that cause infectious
diseases or spread viruses.
Nematodes, however, are a
very diverse group of
organisms, and most are
beneficial. Though some
species feed on plants, others
feed on bacteria, fungi, other
small animals or a combination