African Journal of Environmental and Waste Management

African Journal of Environmental and Waste Management ISSN 2375-1266 Vol. 6 (6), pp. 001-011, June, 2019. © International Scholars Journals

Full Length Research Paper

Growth and yield potential of Echinochloa pyramidalis (Lam.) Hitchc & Chase: A forage plant used in vertical-flow constructed wetlands in Cameroon

Marie-Madeleine NGOUTANE PARE¹*, Doulaye KONE², Ives Magloire KENGNE¹ and Amougou AKOA¹

¹Wastewater Research Unit, P. O. Box 8404, University of Yaoundé I, Cameroon.

²Department of Water and Sanitation in Developing Countries (Sandec), Eawag: Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse, 133 CH-8600 Dübendorf, Switzerland.

Accepted 27 March, 2019

Abstract

This work aims at assessing growth and productivity of Echinochloa pyramidalis in the saline and saline-flooded processes of wetland treatment. Growth characteristics such as density, number of dead plants, height and number of new shoots and biomass production of the plant were studied using 24 laboratory-scale units of vertical-flow constructed wetlands fed with faecal sludge supernatant. Plants collected from the surrounding wetlands were subjected to four salinity levels with electrical conductivity of 2, 3, 6 and 9 dS.m^-1 under both drained and flooded conditions for a 100 day period. The results revealed that salinity and flooding combined with salinity stresses had similar effect on plant survival, height and density, leading to growth and biomass reduction at the higher salinity level than under natural growth conditions. Despite these stress effects, E. pyramidalis remained healthy with no signs of salt or saline-flooding stress injury but higher biomass production. As E. pyramidalis is a forage plant its high biomass production in the wetland treatment systems shows the potential of wetland systems to create a local economy based on forage production and thus the opportunity to link sanitation stewardship to food production. This may contribute to sustain sanitation infrastructures at the same time as increasing food security, especially in developing countries.

Key words: Constructed wetlands, Echinochloa pyramidalis, faecal sludge, flooding, growth, salinity, yield potential.