Re-use
of harvested water hyacinth as organic fertilizer through composting
Water Hyacinths: even though this is seen as a harmful plant or sea
weed, it has it usefulness when used.
A) Water purifier: Water hyacinths can be
used to detoxify water bodies in enclosed areas.
b) Organic manure: It is used in potato
cultivation
c)Bio gas plant: More specifically I recall
chopping large quantity of water hyacinth for biogas production. It is mixed
with the droppings and dung in biogas production.
d) Handicraft: Fiber can be treated and made
to rope. Rope artisans can make different items from the rope..
The
water hyacinth (Eichhornia crassipes) is an invasive plant that is native of
the Amazon basin and whose capacity for growth and propagation causes major
conservation problems with considerable socioeconomic repercussions. The
greatest damage due to its fast expansion has been in the middle reaches of the
River Guadiana in the SW Iberian Peninsula, where was detected in the Autumn of
2004. Due to its rapid expansion, mechanical extraction was carried out by the
Confederación Hidrográfica del Guadiana (CHG) of Spain's Ministry of the Environment
since the affected zone is an important area of irrigation farming and
hydraulic works and this alien plant weed provoked acute social alarm (Ruiz et
al., 2008). In this work we used composting and vermicomposting techniques as
an environmental alternative to assess the possibilities of biotransformation
of the water hyacinth biomass removed mechanically from the Guadiana River
Basin (Spain). Four compost piles 1.5 x 10 m size, mechanically tumbled and
with no forced ventilation (turning windrows system), were constructed outdoor.
Each compost pile was considered as a different treatment: CC1: fresh water
hyacinth / wheat straw (1:1 vol/vol); CC2: fresh water hyacinth / sheep manure
rich in wheat straw (1:1 vol/vol); CC3: fresh water hyacinth / sheep manure
rich in wheat straw (2:1 vol/vol) + Bokachi EM Activator (200 g m-2) to favor
the composting process; CC4: fresh water hyacinth / sheep manure rich in wheat
straw (1:1 vol/vol) + Bokachi EM Activator (200 g m-2). The vermicomposting
process was performed on mesh coated wooden boxes (0.34 m3) covered with a
shadow mesh with the aim of harmonizing the environmental conditions. The
quantities of water hyacinth biomass used were identical in volume (120 l) but
with different state or composition: fresh and chopped biomass (VCF); dry and
chopped biomass (VCS); fresh and pre-composted biomass with sheep manure rich
in wheat straw (VCP). Identical worm density, irrigation type (microaspersion),
irrigation period and vermicomposting process duration (four months) were
adopted. Phytotoxicity tests were performed on Lactuca sativa cv. "cuatro
estaciones" with the aim of finding the appropriate concentrations to be
incorporated to the soil. The composting process required water hyacinth to be
crushed, because only chopping made the process very slow. The greatest
effectiveness was observed with the vermicomposting trials. In the
phytotoxicity tests, the vermicompost extracts did not cause any toxicity at
any of the concentrations studied; however, compost extracts obtained in CC1
and CC3 caused problems in root development. Key words: composting,
vermicomposting, water hyacinth. References Ruiz T., Martín de Rodrigo E.,
Lorenzo G., Albano E., Morán R., Sánchez J.M. 2008. The Water Hyacinth,
Eichhornia crassipes: an invasive plant in the Guadiana River Basin (Spain).
Aquatic Invasions Volume 3, Issue 1: 42-53.
