Abstract:
The invasive water hyacinth (Eichhornia crassipes) poses a significant challenge to Sri
Lanka's water bodies, leading to severe blockages in irrigation and fishing activities. Hence,
this study explored composting as a solution to overcome this constraint. By blending water
hyacinths with locally available resources such as cow dung, goat manure, Gliricidia sepium
leaves, poultry manure, banana peel, and dry leaves, high-quality compost with a balanced
C:N ratio was produced. A Completely Randomized Design (CRD) with three replicates was
implemented across six treatments to form the compost piles. The treatments included T1:
Dry leaves 8% + Goat manure 15% + Gliricidia 5% + Cow dung 20% + Water hyacinth 50%
+ Banana residue 2%, T2: Dry leaves 8% + Goat manure 15% + Gliricidia 5% + Water
hyacinth 50% + Poultry manure 20% + Banana residue 2%, T3: Dry leaves 8% + Goat
manure 15% + Gliricidia 5% + Cow dung 10% + Water hyacinth 50% + Poultry manure
10% + Banana residue 2%, T4: Dry leaves 8% + Goat manure 15% + Gliricidia 5% + Cow
dung 15% + Water hyacinth 50% + Poultry manure 5% + Banana residue 2%, T5: Dry leaves
8% + Goat manure 15% + Gliricidia 5% + Cow dung 5% + Water hyacinth 50% + Poultry
manure 15% + Banana residue 2%, T6: Dry leaves 8% + Goat manure 15% + Gliricidia 5%
+ Water hyacinth 50% + Banana residue 2%. Over a two-month composting period, analysis
of physicochemical properties revealed variations in sand content (1.96% to 5.72%),
moisture (60.67% to 64.67%), and electrical conductivity (0.23 mScm-1 to 0.51 mScm-1).
Encouragingly, all compost types shared a consistent blackish-brown appearance and were
odourless. Chemical properties pH (6.5-8.5), C (< 20%), total N (> 1%), C: N ratio (10-25),
total P (> 0.5%), and total K (> 1%) spanned ranges, however, obtained the quality standards
(SLS 1246:2003), showcasing the potential to produce top-notch compost locally. Data
analysis utilised Minitab 17, applying ANOVA to evaluate treatment variances at p = 0.05.
Post-ANOVA, Tukey's test discerned significant mean differences. The study identifies T3
as the superior composting treatment, achieving high-quality compost with significantly
higher nutrient levels (p<0.05). It showcases composting as a viable strategy to convert the
challenge of water hyacinth invasion into an agricultural benefit, simultaneously mitigating
its environmental impact and producing valuable compost. This approach not only addresses
the issue of invasive species but also advances sustainable agricultural practices by
facilitating the creation of nutrient-rich compost, enhancing agricultural productivity.
Suggestions for future studies include detailed analyses of heavy metal components and the
long-term impacts of using such compost in agricultural settings, ensuring safe and
productive use of water hyacinth compost.
