Desire for Greener Land

No. of case studies
Increased organic matter compared to initial soil organic matter content
9
8
7
6
5
4
3
2
1
0
Cropping
management
Water
management
Cross-slope
barriers
Grazing land
management
SLM technology groups
high medium increase
high no increase
medium medium or high
increase
medium no or little increase
low medium to high
increase
low little increase
low no increase
organic matter was between medium and high for most of
the cropping management technologies. Some increase in
organic matter was also identified in five other technologies
in all groups (except water management).
As stated earlier, most cases indicated a low topsoil organic
matter before implementation. Comparing this with the
impact now does not show high increases.
Surprisingly, most technologies which are applied on soils
with low organic matter content do not improve the problem
at all. This could be because it takes a long time for
such an increase to be seen. Equally, it could be due to the
difficulty of increasing organic matter under dry conditions.
Exceptions are those cropping management technologies,
which aim directly at improving soil organic matter. The
reduced tillage examples from Spain and Greece already
have a medium level of soil organic matter and therefore
only improve it slightly. For all the other case studies,
organic matter improvement is only one amongst several
major impacts. Most of the water management, the crossslope
barriers and the forest management technologies do
not impact on soil organic matter. However the reason for
this could be that, due to its insignificance for these technologies,
increasing organic matter was not assessed. This
is despite the fact that the build-up of soil organic matter is
much larger in grassland and forest under sustainable land
Forest
management
DESIRE - WOCAT 2012
Figure 23: Increased organic matter compared to initial soil
organic matter content.
management. This is probably because soil organic matter
plays a more important role as an input factor for agricultural
productivity on cropland.
Reduced soil crusting and sealing was not only observed
for the reduced contour tillage example of Spain, where it
was indicated as an observed degradation type, but also for
some other technologies.
These are almost all within the cropping management
group, where the Greece example of olive groves under
no tillage showed the highest impact with over 50% of
crusting reduction. The same level was also achieved by the
other Greece example, the transport of freshwater from
local streams, as salinization and, as a result, crusting is also
reduced tremendously.
Vegetation issues
As improved soil cover (by crops, fodder, weeds, shrubs or
dead material) is usually linked to more vegetation cover,
it is for these same technologies that an increase in biomass
(and related above ground carbon) was reported. An
increase in soil cover or biomass was not indicated for any of
the water management technologies. Although there were
reports about increased production, it did not improve the
level or time of soil being covered.
Improved soil cover
9
Analysis of assessed SLM technologies and approaches across DESIRE sites DESIRE – WOCAT 2012
No. of case studies
8
7
6
5
4
3
2
1
0
Cropping
management
Water
management
Cross-slope
barriers
Grazing land
management
SLM technology groups
Forest
management
no
little
medium
high
DESIRE - WOCAT 2012
Figure 24: Improved soil cover across the SLM technology
groups.
China, Erik van den Elsen Morocco, Gudrun Schwilch
53