Chemistry Reference
In-Depth Information
7.2 Drivers of Farmers' Use of Sustainable Soil Conservation
Practices
Farmers adopt new practices that enhance soil biodiversity only when the switch
from the old to new methods offers additional gains either in terms of higher net
returns, lower risks, or both. Thus farmers are likely to adopt soil biodiversity-
enhancing practices only when the additional benefits from such investments
outweigh the added costs.
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Investment in such soil conservation practices is often
just one of the many investment options available to farmers. They can therefore
defer undertaking such conservation investments until the gains from such
investments are perceived to be at least equal to the next-best investment
opportunities available to them.
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That is, farmers will implicitly compare the
expected costs and benefits and then invest in options that offer highest net returns
in terms of income or reduced risk. This implies that, in cases where private costs
of investment in soil biodiversity outweigh the benefits, voluntary adoption will be
greatly hampered and may only occur if the society is willing to internalise some of
the costs by offering subsidies to farmers. This is indeed the reason why some
development experts promote the payment for environmental services.
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The literature identifies a number of factors that condition the adoption of soil
conservation practices in agriculture. These factors relate to incentives the
farmers have and the capacity of such farmers to adopt better practices. Farmers
can be constrained to adopt otherwise profitable (or economically attractive)
interventions due to asset poverty (i.e. low endowment with needed capital
items), imperfect information, poorly functioning markets, bad policies, and
institutional factors. Thus the factors that condition the adoption of soil
biodiversity can be broadly categorised into incentive factors, capacity factors,
institutional (e.g. markets and policy) factors and information-related factors.
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8 Synthesis
In summary, the recognised form of land degradation affecting the major soil
types in sub-Saharan Africa are erosion, physical and chemical degradation,
which includes salinisation, sodification, acidification and the depletion of plant
nutrient content in the soil. Biological degradation is also a major contributor
leading to loss of soil organic matter and soil biodiversity. All these forms of
degradation lead to a lowering of soil fertility and land productivity. Land
degradation problems are now recognised as being one of the major contributors
to the persistent food deficit and high poverty levels in the sub-Saharan Africa.
The main causes of low land productivity in smallholder farms include very low
use of organic and inorganic fertilisers; poor tillage practices, especially for hard
setting soils such as Luvisols, Lixisols and Acrisols; excessive soil erosion by
water and wind, affecting almost all the major soil types; lack of attention to soil
acidity for soils with acidity problem; poor conservation and management of
rain water for enhanced soil moisture conservation on soils occurring in rolling
to undulating topography; and poor land-use planning. Concerted and well-
