Conservation farming on steep lands - USAid

CONSERVING SOIL BY STEALTH 11
P
Vegetative
growth
Farmers'
interests
and Root function gro;;?h
t
More
plant leaves,
phctosynthesis
per hectare
Plant
production
Cover,
' residues
<strong>Conservation</strong>ists'
interests
Improved soil
throughout conditions 4- Infiltration,
available water
effective depth
Figure 2. Integrating water and soil conservation with agriculture (3).
infiltration capacity and soil structure, which are also the conservationist's
aim (Figure 2).
Some technical aspects
A major challenge we have is that of increasing plant production per
hectare per year without degrading or destroying the soil in the process.
We have not been very successful so far in achieving both aims simultaneously,
chiefly because intensifying plant production often has meant more
tillage. This degrades both soil structure and rooting conditions and makes
the soil more susceptible to erosive forces. In this context, all forms of
reduced-, minimum-, or no-tillage offer advantages both for plant production
and soil conservation.
A lack of distinction between "conservation" and "reclamation" has ofien
resulted in too much emphasis on programs for repairing spectacular damage
and too little on the preservation of productive lands not yet seriously damaged.
To emphasize reclamation where there is inadequate social or economic
justification can waste scarce resources. Encouragement of the growth
of recolonizing vegetation may be the most economic means of stabilizing
seriously degraded land.