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
email: aanaya@ifcsun1.ifisiol.unam.mx

Sergio Palacios Mayorga

UNAM
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
email: palacios@servidor.unam.mx

and

Eleazar González Velázquez

UNAM
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 sulfate.

Spanish Version