1 research outputs found
Sustainable Soil Management Is More Than What and How Crops are Grown
Soil management in agricultural landscapes should deploy production practices
that are in harmony with soil-mediated ecosystem functions if they are to deliver
a broad range of ecosystem services. Such services include edible and nonedible
biological products, clean drinking water, processes that decompose and transform
organic matter, and cleansing processes that maintain air quality. Several categories
of
ecosystem
services
are
recognized:
provisioning,
regulating,
cultural,
and
supporting
(Millennium
Ecosystem
Assessment
[MEA]
2005).
In
agricultural
landscapes,
provisioning
ecosystem
services
can
be
delivered
effectively
and
efficiently
when
the
linked
regulatory
and
supporting
services
are
allowed
to
operate
normally.
Ecosystem
functions
that
protect
and
enhance
regulatory
and
supporting
ecosystem
services
in
the
soil
and
landscape
in
which
crops
are
grown
appear,
in
general,
to
offer
an
effective
way
of
harnessing
the
best
productivity,
ecological,
and
economic
performances.
Thus, agricultural soil management can only be considered sustainable if field
soil health and productive capacity are kept at an optimum to provide ecosystem
services such as provision of clean water, hydrologic and nutrient cycling, habitats
for microorganisms and mesofauna, carbon sequestration, and climate regulation.
Across agricultural and mixed land use landscapes, such ecosystem services form
the necessary conditions for society to be able to sustainably harness the biological
potentials of the altered agroecosystems and the associated provisioning services of
food, vegetation, water, etc.
In general, over the past several millennia, agricultural land use globally has led
to soil physical, chemical, biological, and hydrological degradation, and this state of
affairs continues unabated in most farmlands (MEA 2005; Montgomery 2007; FAO
2011a). This is true on small and large farms, on farms using mechanized or manual
farm power, in developing and in industrialized countries, in the tropics, and outside
the tropics. The dominant farming systems paradigm globally is based on mechani-
cal tillage of various types to control weeds (often along with herbicides), soften
the seedbed for crop establishment, and loosen compacted subsoil. At the center of
this paradigm, there are farming practices for crop, soil, nutrient, water, and pest
management that are considered by most agricultural stakeholders to be “modern,
good, and normal.” However, the same farming practices have also forced farmers to accept that, supposedly, any accompanying soil degradation and loss of ecosystem
services
are
inevitable
and
“natural”
consequences
of
farming—consequences
that
can
be
kept
under
control
but
not
avoided
altogether.
This
view
is
increasingly
being
challenged
and
considered
to
be
outdated,
and
inherited
farming
practices
are
considered
unable
to
deliver
the
multifunctional
objectives
of
productivity
with
ecosystem
services
now
being
demanded
from
agricultural
land
and
producers
who
use
it
for
farming.
In the past three decades, ideas and concepts, as well as an ecosystem approach
to sustainable production intensification, have led to the emergence of an alternative
approach to farming across all continents. The title of this chapter is “Sustainable
Soil Management Is More Than What and How Crops Are Grown.” Not only how
and what crops are grown matters but also the interactions of the two in space
and time lead to effects and consequences that influence system performance and
delivery of ecosystem services. Some ecosystem services involve processes such as
hydrological, carbon, and nutrient cycling that operate at the level of the fields on
farms, landscapes, watersheds, and beyond. In addition, agricultural soil management
is
undertaken
within
different
farming
systems
for
the
purpose
of
producing
biological
products
for
markets,
and
a range
of
production
inputs,
equipment
and
machinery,
and
management
skills
are
needed
to
operate
successfully.
Thus,
the
topic
of
sustainable
soil
management
has
a wide
and
complex
scope
as
reflected
in
the
list
of
10
tenets
proposed
by
Lal
(2009).
This chapter is about soil degradation in agricultural land, its root causes, and what
solutions are being implemented in different parts of the world to integrate sustainable
soil management into sustainable farming and landscape management. Section 14.2
describes what is meant by agricultural soil degradation and its extent. Section 14.3 provides
an
explanation
of
some
of
the
major
causes
of
soil
degradation
in
agricultural
land
use
and
illustrates
three
cases
of
widespread
soil
degradation
in
contrasting
environments.
This
is
followed,
in
Section
14.4,
by
a discussion
on
the
elements
of
sustainable
soil
management.
Section
14.5
provides
an
elaboration
of
sustainable
soil
management
based on the agroecological paradigm that is increasingly being promoted internation-
ally, including how sustainable soil management has been able to restore degraded soils
in different agricultural environments. Section 14.6 illustrates the kind of contributions
crop management, intercropping, crop–livestock integration, and farm power that can
make to sustainable soil management objective. Section 14.7 presents three examples
of large-scale landscape level ecosystem service benefits that are being harnessed from
sustainable soil management systems. This is followed by Section 14.8 on policy and
institutional implications for sustainable soil management. Section 14.9 offers some
concluding remarks regarding the current trend toward sustainable soil management
and what policy makers can do to support the trend