Mr Simon G. Macharia, Mkokoteni Aid Development Organization (Mado), Kenya. Global Symposium on Soil Erosion (GSER19), 15 - 17 May 2019 at FAO HQ.

1. The economics of soil erosion prevention,
management and remediation
Mr. Simon G. Macharia, Executive Director/ Research, Mkokoteni Aid Development
Organization (Mado), Kenya
INTRODUCTION
Fig 1. Contour banks and strip cropping in Laikipia,
Kenya
AGRICULTURAL
PRICING POLICIES
AND SOIL EROSION
Government intervention in agricultural
markets can have significant impacts on
farm-level incentives for soil
conservation, whose regulations whose
artificially suppress producer prices
create disincentive to invest in land
husbandry. Attempts to predict the
direction of the effect (positive or
negative) of a change in either input or
output prices on the aggregate level of
current and future production, and hence
soil erosion, highlight the dynamic nature
of the soil conservation problem (Figure
2).
Mado analysis is that few conservation
measures are likely to be attractive to the
smallholders farmer due primarily to the
already low productivity of this sector.
However the results are primarily
tentative in nature while attempting to
identify critical areas for further
investigation. Our simulation study also
compares alternative measures of the
attractiveness of different cropping
systems to the farmer.
CONCLUSION
Fig 2. Green cane planting, Western Kenya
More formally, by increasing the
profitability of agriculture, an increased
price has lead farmers in central, western
and some parts of Rift Valley to use more
inputs and increase agricultural output
through either intensification or
cultivating more land. Using more non-
conservation inputs will tend to increase
the rate of erosion, assuming that
production increases can only be
achieved in the short term at the expense
of increased erosion.
But the increase in profitability will also
create an incentive to conserve the soil as
an agricultural “input”, implying greater
soil depth and less erosion.
Soil erosion is widely considered to be a
serious threat to the long-term viability of
agriculture in many parts of the world.
Kenya is not an exception and this
concern is not without precedent whose
downfall was caused at least in part by
excessive soil erosion and the
deterioration of the agricultural base
(Kenya Agriculture Research Institute
1981).
The problem is particularly serious in
certain developing countries, where the
importation of food to substitute a
declining domestic production due to soil
erosion, and the growing scarcity of
arable land may be severely constrained
by low foreign exchange earnings and
high external debt burdens. In other
cases, agricultural products may
themselves constitute a country’s main
source of foreign exchange.
Declines in agricultural productivity
resulting from soil erosion would
therefore hinder such a country’s
economic development, particularly in
the absence of other export opportunities.
In addition, many countries can
anticipate continued expansion of
agricultural production, for either
domestic consumption or export, due to
rapidly expanding populations.
Mado, examines the considerations taken
into account by smallholders farms in
making decisions Laikipia (Kenya) about
soil depletion and conservation (Figure
1). In the natural resource economics
literature, there is a strong interest in the
issue of farmer decision-making and soil
erosion. Much of this work focuses,
however on the Kenyan chapter.
Using a simple variant impact of a price
change cannot be generalized because of
its contradictory effects. While an
increase in the output price creates an
incentive for increased soil erosion in the
current period (to increase production
and profits) the price increase if it is
permanent, also increases returns to
future production and thus creates an
incentive to conserve more soil for future
use.