A. Dody et al. / Natural Science 3 (2011) 476-483
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482
spp. was found to be a good parameter to present the
development of the crust (although only 1 gram of soil
surface was taken for each replicate). Because protein
and organic content are related to two other variables,
the standard deviations were relatively too high, in order
to identify clear trends in the development of the crusts.
The sandy soil used for the experiments was taken
from a depth of 30 cm, under the assumption that no
spores and propagules existed at that level. The fact that
there were changes in all the parameters in the pure sand
treatment used as reference proves that our assumption
was wrong.
The next stage of our study focuses on the develop-
ment of a bio-reactor to grow BSC spores and propa-
gules, as well as to figure out optimum conditions (bio-
logical and cost-beneficial). The spores and propagules
will be seeded on the target areas in order to shorten the
coverage time of the area with BSC (compared to natural
growth).
More field experiments are needed to study the appli-
cations under field conditions, but our preliminary re-
sults showed fast establishment of the spores on sand
dune soil at the north-eastern Negev Desert (Yamin pla-
teau). Again, for the point of view of WDS, it must be
stated very clearly that the idea of using the BSC is not
to replace any other engineered barriers, but to add an
additional top layer that increases the soil surface stabil-
ity by using natural components of the ecosystem in the
arid landscape.
5. CONCLUSIONS
NDVI, polysaccharides and infiltration rates are good
indicators for showing growth acceleration of the
crust;
Protein and organic content were found to be less
indicative.
The treatments using whey for preliminary crust
failed in the lab since cracks were observed, but suc-
ceeded in the field experiments.
In the field, we measured only the chlorophyll con-
tent with a time interval of 20 months.
The methodology of how to accelerate the growth of
BSC was found to be effective.
6. ACKNOWLEDGEMENTS
The authors wish to thank Faina Tziperman from Gilat-ARO for her
assistance in the laboratory work and Catherine Kelly for reviewing the
English.
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