Sustainable Soil Management Is More than What and How Crops Are Grown - Principles of Sustainable Soil Management in Agroecosystems - page 356

essential to (1) biotic activity; (2) provision of water and crops; and (3) assurance of
self-sustainability of soil structure and porosity.
These include capacities for achieving the following: maximum rain infiltration/
minimum runoff and optimum water storage; minimum compaction; reduced diur-
nal temperature ranges in upper soil layers; regular supply of C-rich organic matter
to the surface; minimal loss of SOM by oxidation; N levels in soil maintained; and
optimized P availability. Such are best achieved by incorporating the following three
main tenets of CA as a base or a foundation for sustainable soil management (see
www.fao.org/ag/ca ) :

1. Minimizing soil disturbance by mechanical tillage . Whenever possible,
seeding or planting directly into untilled soil, in order to maintain SOM,
soil structure, and overall soil health.

2. Enhancing and maintaining permanent mulch cover on the soil surface .
Use of crops, cover crops, or crop residues to protect the soil surface con-
serves water and nutrients, promotes soil biological activity, and contributes
to integrated weed and pest management.

3. Diversification of species . Utilize both annuals and perennials in associa-
tions, sequences, and rotations that can include trees, shrubs, pastures, and
crops (some or all of which may be N-fixing legumes). All will contribute
to enhanced crop nutrition and improved system resilience.

CA practices related to the above-described principles are now widely used in a
range of farming systems in all continents on nearly 10% of the global crop land.
They add to sustainability of production and soil systems and generate a range of
ecosystem services ( Table 14.1 ). They also improve soil conditions ( Table 14.2a ) and
result in beneficial outcomes for production, ecosystem services, and socioeconomic
conditions ( Table 14.2b ). However, to achieve the sustainable intensification neces-
sary to meet future food requirements, these CA practices need to be complemented
by additional best management practices:

• Use of well-adapted, high-yielding varieties, and good-quality seeds

• Enhanced crop nutrition, based on healthy soils

• Integrated management of pests, diseases, and weeds

• Efficient water management

• Careful management of machines and field traffic to avoid soil compaction

Sustainable crop production intensification (SCPI) is the combination of all of
these improved practices applied in a timely and efficient manner. For this, the
ensuring of soil stability and the favoring of self-recuperation of appropriate soil
structural conditions are essential (see Table 14.1 and Figure 14.1a and b). Thus, sus-
tainable soil management depends on how and what crops are grown. However, for
sustainable production intensification to occur, the core or foundation CA practices
must integrate with other complementary practices that allow the intensification of
output and the optimization of the production inputs. Such sustainable production
systems, and the associated sustainable soil management practices, are knowledge