Desire for Greener Land

No. of case studies
Soil fertility
9
8
7
6
5
4
3
2
1
0
Cropping
management
Water
management
Cross-slope
barriers
Grazing land
management
SLM technology groups
very low
low
medium
high
degradation problems requiring mitigation action in these
areas. Cropping management and water management technologies
are mainly applied on flat to gentle slopes, where
other degradation problems are prevalent, such as fertility
depletion, vegetation degradation or salinization.
23 of the 30 technologies (77%) are practiced on soils with
low or very low soil fertility. None of the case studies are
applied on soils which initially had a very high fertility and
only one technology is on a soil with high initial fertility.
Compared to earlier assessments, including all climatic
zones 4 , more focus is given to improve the management of
low fertility soils in the drylands of this study. This reflects
the reality of drylands, where soils are generally less fertile
due to less weathering and the prevalence of unfavourable
substrates. It has not been assessed how far degradation and
nutrient mining have contributed to a reduced soil fertility.
Topsoil organic matter is closely related to soil fertility and
has an impact on physical, chemical and biological properties.
Similar to soil fertility, the majority of cases have low
topsoil organic matter. Naturally, topsoil organic matter is
rather low in drylands due to the reduced biological activities
under arid and semi-arid climatic conditions. Because
most soils where SLM has been applied contain a low level of
soil organic matter, they have potential to increase organic
Forest
management
DESIRE - WOCAT 2012
Figure 9: Level of soil fertility in relation to the SLM technology
groups before intervention. (Note that for each technology
only the major category was selected).
Morocco, Gudrun Schwilch
China, Erik van den Elsen
Availability of surface water
9
Cropping
management
matter and nutrient holding capacity and simultaneously
sequester carbon in the degraded soil. This is an important
functionality of reduced tillage, crop rotation with legumes
and agroforestry systems.
Figure 23, which is presented later in this chapter, shows an
interesting comparison of the initial soil organic matter and
the impacts of the SLM technology.
As expected, the availability of surface water (proximity of
streams or lakes) is very poor in most cases (see Figure 10).
More on the impacts of this issue can be found below.
Sensitivity of, and tolerance to, climate change
The technologies were documented for the current climatic
situation of the study sites. If climate is changing, then the
positive-functioning of a technology could be negatively
affected. Equally, under certain situations the effect could
be positive. If the species used are not drought tolerant,
a reduction of seasonal rainfall may cause hedge rows to
become ineffective. The WOCAT questionnaire therefore
assesses the perceived tolerance and sensitivity of an applied
technology during extreme conditions, be it seasons with
exceptionally low or high rainfall, temperatures or heavy
storm (wind or rain).
4 WOCAT, 2007
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
Water
management
Cross-slope
barriers
Grazing land
management
SLM technology groups
Forest
management
poor / none
medium
good
DESIRE - WOCAT 2012
Figure 10: Availability of surface water in relation to the SLM
technology groups. (Note that for each technology only the
major category was selected).
45