Integrated soil fertility
Practical Action
What are the major constraints
Farmers in semi arid areas are attempting to improve soils, but their efforts are constrained by
limited access to knowledge, low resource endowments, and lack of incentives. The high level
of poverty lies at the heart of soil fertility degradation problem. Wealthier households, with
more options available, are more likely to manage their soils better.
Poor households lack knowledge of soil management options, the capacity to invest in soils
(especially in fertiliser), and have less ability to bear risk and wait for future payoffs from
investment.
Farmers have reduced their use of inorganic fertiliser as a consequence of their higher prices,
following devaluation, abolition of subsidies and credit systems, and break up of state bodies
responsible for marketing and input distribution.
Integrated soil fertility management
The aim of improving soil fertility management is to contribute more broadly to sustainable
rural livelihoods. Farmers are usually aware of the need to improve soil fertility and allocate
the various sources of nutrients available between crops and soils according to their differing
needs and expected returns. There are various pathways which can be followed such choices
include: direct interventions to improve soil status, strengthening farmer knowledge and skills,
and improving organisational linkages which promote better learning and sharing of ideas. One
main strategy that can be adopted in semi arid areas is integrated soil fertility management.
The strategy at macro-level is aimed at supporting the evolution of policies bringing greater
benefit to the farming sector, while at the same time providing support to networking between
various organisations working on soil fertility issues at micro-level.
Integrated soil fertility management combines a mix of organic and inorganic materials, used
with close attention to timing and placing of the inputs to maximise nutrient use efficiency. It
provides an approach, which needs to be tailored to the characteristics of the site, and
constraints faced by the farmer. This approach demands an emphasis on context-specific,
adaptive responses based on a new partnership between researchers, farmers and extension
workers.
Such skills can be strengthened by farmer field schools, farmer led events such as green fairs,
seed fairs, training activities, and action-research approaches which involve, for example, joint
elaboration and analysis of resource flow maps. Choice of intervention strategy will be
determined by context.
Integrated soil fertility management in practice
There are wide differences in terms of what farmers can do depending on their access to land,
labour, livestock, capital and knowledge. Each site presents a diverse array of methods by
which people try to maintain the fertility of their soils, such as use of different nutrient
sources, choice of crops, and making best use of variability within the landscape with regard to
soil type, location, and moisture regime through the development of in-field and out-field
systems.
In the South west parts of Zimbabwe (Chivi, Zvishavane, Mberengwa and Gwanda districts)
farmers have significantly contributed to the development of sound soil management
principles that aim at sustainable crop production without compromising the ecosystem
service functions of the soil. These include: Application of organic resources of animal or plant
origin in combination with mineral inputs to maximise input uses efficiencies.
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