5. CONCLUSIONS
Agricultural practices change the hydrophysical properties of páramo
soils that are associated to the hydrological service of streamflow
buffering. The information shown in this paper represents an
understudied ecosystem, dry páramos, that differs from the more studied
humid páramos. It shows that changing natural vegetation to potato
crops, onion crops and later, livestock, leads to a reduction in soil
organic matter and water content and an increase in bulk density,
especially at the surface level. This trend was evidenced by the decline
of these variables in the areas transformed to fallow soil. Furthermore,
páramo soils under anthropic uses showed higher variability in these
hydrophysical properties with rainfall seasonality.
Activities such as ploughing, agrochemical use and irrigation influenced
the hydrophysical properties of the páramo soils under onion crops,
where the gradient on the hydrophysical properties according to depth
–typical of natural areas– disappeared. In addition, substantial
changes in pH and electric conductivity were observed. Even if
irrigation contributes to preserve water content, and frequent
fertilization provides organic matter, the organic matter content
decreases in the long-term with extended cultivation. Furthermore, as
the soil hydrophysical properties are severely compromised, this leads
to the abandonment of these lands and their conversion to fallow.
The increase in bulk density, electric conductivity and the reduction in
organic matter could impair the ability of páramo catchments for
streamflow buffering. This will increase surface runoff and reduce base
flow, which worsens the capacity of páramo catchments to maintain steady
flows and allow multiple water uses. It is extremely important to
develop strategies that can communicate this information to
decision-making institutions and farmers aiming at a collaborative
search of best practices that provide opportunities to harmonize
people´s livelihoods with environmental conservation of páramos and of
the ecosystem services dependent on them.