Sustainable Agriculture and Food: Four volume set (Earthscan Reference Collections)

Ways Forward? Technical Choices, Intervention Strategies and Policy Options 361

amount of labour needed to recycle biomass through manuring and composting
systems. Such extensive strategies are clearly apparent in Siguiné, Mali. Farmers are
likely to moderate such ‘soil mining’ where they see declining yields and where
they depend on this land for future harvests. Cotton farmers in M’Peresso, Mali
are starting to engage in much more intensive nutrient management, following
similar patterns as those in the more nutrient scarce sites of Ethiopia and Zimba-
bwe studied here.
Efforts to ‘recapitalize Africa’s soils’ and to replenish soil fertility need to take
into account the broad-based nature of the farm household enterprise. This means
that farmers have to weigh up the advantages of investing further effort in improved
soil management in comparison with the much broader range of decisions they
face, such as the gains from allocating labour to migration, more time spent on
trading activities and the need to allocate resources for a forthcoming wedding.
This finding points to the importance of setting soil-fertility management within
a broader livelihoods approach (Carney, 1998; Scoones, 1998), a theme picked up
later in this chapter.

Technological Choices

If the ultimate goal of intervention in soil-fertility management is to increase use-
ful outputs for improving livelihoods, there are a variety of routes to do so, each
with differing technological choices. Table 19.1 identifies four clusters of techno-
logical options. One focuses directly on the soil resource, by attempting to improve

Table 19.1 Technology choices for managing stocks and flows of nutrients

Managing stocks Managing external flows Managing internal

flows

Increasing nutrient

stocks

Increasing nutrient

inputs

Decreasing nutrient

outputs

Increasing nutrient

use efficiency

P – Recapitalization

through rock

phosphate or other

P additions

Inorganic fertilizer Erosion control Composting; residue

recycling

Manure/urine Reduce leaching

(mulching, deep

capture through

agroforestry, tillage

systems)

Water management

N-fixation (legumes)

N – Organic matter

build-up

Fallowing, green

manure,

agroforestry etc

Crop choice and

management

Biomass import

(leaf litter etc)

Reduce

volatilization

(manure/urine

management)

Fertility input

combinations

Input placement and

synchronization

Source: Scoones and Toulmin, 1999