Agriculture Reference
In-Depth Information
individual smallholders is much more difficult. Some agronomists, however, chal-
lenge the potential of conservation agriculture if only because of the limited amount
of crop residues left on the land (e.g., Giller et al. 2009). When applied correctly,
irrigation can also strongly improve yields (e.g., IAC 2004). However, it requires
a relatively high level of technical expertise that can be applied most effectively in
larger irrigation schemes. Again, introducing irrigation on 2-acre fields has little
potential. This supports the long-range vision of Rockstrom et al. (2009) that large
and modern production systems are needed to satisfy the needs of an ever-wealthier
population in the decades to come. The Dutch case studies suggest that there may
also be local potential for intermediate-size family farms.
2.6 CONCLUSIONS
Five major conclusions are derived from this study:
1. Soil security is expressed in terms of the degree to which ecosystem services
can be provided. The sixteen ecosystem services defined by MA (2005)
can, for simplicity, be related to the seven basic soil functions defined by
CEC (2006). Large differences among smallholder conditions in differ-
ent countries, as reviewed in this chapter, make unified expressions of soil
security less meaningful and require a local approach taking into account
socioeconomic and institutional issues.
2. Recent reports on smallholder agriculture pay little attention to soils. IFAD
(2012) mentions conservation agriculture, use of fertilizers, and irrigation
as possible soil-related activities that may improve ecosystem services and,
in turn, soil security. In this chapter, the very general term “use of fer-
tilizers” is explored by analyzing the various ways in which optimal use
of fertilizers has been investigated during the last hundred years, as well
as ways in which this knowledge has been communicated to farmers. The
traditional top-down approach is now being replaced by interactive joint
learning in both developed and developing countries.
3. Case studies in Zimbabwe (Arenosols) and Kenya (Vertisols) demonstrate
conditions where ecosystem services are inadequate, as production levels
remain below that required by the farming families to meet their food need.
This applies to studies in several other countries. Current socioeconomic and
institutional conditions do not offer obvious future perspectives for improve-
ment. However, Nitosols in Kenya and Luvisols in Zimbabwe presented an
adequate, be it marginal, level of ecosystem services. Rather than only perform
classical soil fertility experiments, focusing on surface soil, the suggestion is
made to (i) also consider subsoil conditions as defined in soil classification
in terms of genoforms, and (ii) look for “lighthouse” examples where farm-
ers, working with a given soil type, have achieved unexpected success. Then,
genoforms can be used as a “carriers” of valuable management information.
4. A study on Gleyic Podzols and Sapric Histosols in the Netherlands demon-
strated bottom-up actions of farmers applying cradle-to-cradle techniques
that resulted in six clearly improved ecosystem services and thus improved
