Periphyton of the El Edén
Ecological Reserve, Quintana Roo, Mexico: A Potential Biofertilizer
for Agricultural Purposes
Ana Luisa Anaya
UNAM, Instituto de Fisiología Celular
Laboratorio de Ecología Química
Apdo Postal 70-243
México D.F. 04510 México
tel: (52-5) 622-5664
fax: (52-5) 622-5611
Sergio Palacios Mayorga
Instituto de Geología
Calle Teja 157
Col. Jardines del Sur
Xochimilco D.F. 16050 México
tel: (5) 622-42-86
fax: (5) 550-84-32
Eleazar González Velázquez
Instituto de Fisiología Celular
The periphyton is recognized as the floating
biomass of the continental water bodies, permanent or temporal, of the
Savanna at the El Eden Ecological Reserve. The biological composition
of the periphyton is very complex. However, its main component is the
algae that constitute the substrate for the bacterial community and
an ecological niche for protozoa and microcrustaceous, among other organisms.
The periphyton originated in temporal
lagoons, located in flooding areas of the El Eden Savanna, turns into
a very evident crust that cover the soil.
Once this crust of periphyton is ground
and homogenized, it shows particular physical and chemical proper ties.
Among these the most relevant are:
a) a very high contents of organic matter,
nitrogen and phosphorus (32, 3 and 0.8 %, respectively);
b) a high cation exchange capacity (100
meq/100 g), and
c) a high content of exchangeable K,
Ca and Mg (25, 110 and 15 meq/100 g, respectively).
The richness in nutrients of the periphyton
leads to consider the probable role that it had as a biofertilizer,
used by the Maya people settled in that region.
Based on this hypothesis, an experimental
design, entirely at random, was established, allowing a relative readily
way to evaluate the effect of periphyton on the growth of some cultivated
plants (lettuce, corn and tomato) as well as on the establishment of
arbuscular mycorrhiza in these three species. The experiment was established
under greenhous e conditions, using plastic seedling-nursery trays.
Calcimagnesic soil, poor in nitrogen and phosphorus was used. This soil
had shown a good mycorrhizal potential (80 propagules/g of dry soil).
To determine the role played by the microorganisms
from the periphyton as well as from the soil, the experiment was carried
out on both soils, sterile and none sterile.
Results of foliage dry weight on none
sterile soil indicate a positive effect from the periphyton on the growth
of the three plants. On tomato plants, a similar effect as that obtained
with ammonium sulfate was observed. On sterile soil, the periphyton
effect on the three test plants was more notable than that with ammonium
sulfate. Finally, the mycorrhizal colonization percentages indicate
a positive effect with periphyton on mycorrhizal establishment, markedly
greater on lettuce and maize, compared with that obtained with ammonium