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Asian Journal of Water, Environment and Pollution. Vol. 22, No. 1 (2025), pp. 115-121.
doi: 10.36922/ajwep.7526

ORIGINAL RESEARCH ARTICLE

Saturated hydraulic conductivity of soils in the presence
of vermicast: Effects of soil texture and vermicast sizes

Sajal Roy , Rakib Hossain , Md. Akhtaruzzaman , and Azizul Hakim*

Department of Soil Science, Faculty of Biological Sciences, University of Chittagong, Chattogram, Bangladesh
*Corresponding author: Azizul Hakim (ahakimsoil@cu.ac.bd)

Received: December 13, 2024; 1st revised: February 23, 2025; 2nd revised: February 26, 2025; Accepted: March 3, 2025;
Published Online: March 19, 2025

Abstract: The present experiment was conducted to observe the effects of different size fractions of vermicast on
the saturated hydraulic conductivity (Ks) of loam and sandy loam soils. To set up the experiment, loam and sandy
loam soils were incorporated with vermicast of different sizes as raw, 1.0 – 2.0 mm, 0.5 – 1.0 mm, and <0.5 mm,
at 0, 5 t/ha, 10 t/ha, 15 t/ha, and 20 t/ha, which resulted in five different treatments for each soil type. The Ks was
determined based on the principle of Darcy’s Law by maintaining a constant water head on the top of the soil
column. Results indicated that sandy loam soils had significantly higher Ks than loam soil for all the application
rates (p < 0.01). Irrespective of the size, the applications of vermicast at the rates of 5 t/ha, 10 t/ha, 15 t/ha, and
20 t/ha resulted in 113.67 – 196.79%, 135.47 – 442.76%, 10.0 – 150.0%, and 29.63 – 135.47% higher Ks in sandy
loam soils relative to the loam soils. There were significant differences in Ks among the vermicast sizes at all the
rates of incorporation for both loam and sandy loam soil treatments (p < 0.01). As the size of vermicast decreases
(<0.5 mm), the Ks also decreases relative to the control, indicating the greater retention capacity and water-holding
capacity of finer vermicast fractions in the soil column. At 15 t/ha and 20 t/ha, the highest relative Ks (74.42% and
88.37%) were found in loam soils with raw vermicast.

Keywords: Saturated hydraulic conductivity; Loam soils; Sandy loam soils; Vermicast sizes

1. Introduction materials with earthworm assistance, has gained a lot
of popularity recently. Vermicompost is an effective,
Environmentalists and soil scientists find it difficult economical, environmentally safe, and sustainable
to maintain soil health to achieve sustainable food organic fertilizer that is made by employing epigeic
production while minimizing environmental pollution. earthworms to compost a range of organic materials.
8,9
The most important method for improving the physical, Vermicompost enhances the chemical and physical
chemical, and biological characteristics of soils is properties of soil, including cation exchange capacity,
the application of organic manure. Various organic organic carbon content, availability of plant nutrients,
1-5
resources, including kitchen trash, cattle manure, and soil porosity, water retention capacity, soil structure,
poultry manure, have been examined and proven to be infiltration rate, and erosion resistance. 2,10-13
successful in boosting agricultural yields, strengthening The key soil characteristics that either directly or
soil fertility, and improving soil conditions. indirectly influence other soil behaviors are the hydraulic
6,7
Vermicomposting, the technique of composting organic properties. Predicting the soil–plant–water relationship,

Volume 22 Issue 1 (2025) 115 doi: 10.36922/ajwep.7526