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Roy, et al.

A B

C
D

Figure 2. The Ks of loam and sandy loam soils at different rates of vermicast incorporation: 5 t/ha (A),
10 t/ha (B), 15 t/ha (C), and 20 t/ha (D)

and shape of the pore space affecting the water-holding values at the 10 t/ha, 15 t/ha, and 20 t/ha application
capacity and flow of water. 21,33 rates, respectively. The initial high organic matter
content in loam soils induces more binding, and the
3.2. Effect of vermicast sizes on Ks in loam and formation of large-size particles increases the large-size
sandy soils pore distribution, which could be another reason for
The relative Ks of loam and sandy loam soils are shown higher Ks. Applying compost, rice straw, and sawdust
in Figure 3. There are significant differences in the Ks to clay loam-textured soil improved the soil’s pore size,
among the vermicast-amended loam and sandy loam hydraulic conductivity, and water-holding capacity,
soils (p < 0.01). As for loam soils, 5 t/ha, 15 t/ha, and according to Eusufzai and Fujii. 34
20 t/ha applications of raw vermicompost resulted in Çal and Barik reported that the soil Ks was
16
60.43%, 74.42%, and 113.16% higher Ks, respectively, positively correlated with soil organic matter. However,
compared to the corresponding lowest values. This Sari observed an insignificant positive relationship
19
increase of Ks with the addition of vermicast is between hydraulic conductivity and organic matter. At
comparable with the findings of Hemdan et al. In a pot a low rate of incorporation (5 t/ha), the Ks decreased
22
experiment, Hemdan et al. found that incorporating in almost all the treated soils compared to the control
22
vermicast into agricultural loamy clay soils increased except for raw vermicast. This could be due to the
their hydraulic conductivity by 61.47%. In the case greater role of vermicast on water retention than water
of 5 t/ha in sandy loam soils, the maximum Ks was flow at low rates of incorporation. Bhanwaria et al.
10
observed due to the application of a raw cast, followed also observed a significant increase in water retention
by a cast with a size of 1.0 – 2.0 mm. As for 10 t/ha, by vermicompost at an even lower rate of incorporation
15 t/ha, and 20 t/ha applications of different types of (5 t/ha). Incorporating the raw cast at 5 t/ha resulted in
vermicast in sandy loam soils, the highest Ks were a 16.28% and 5.51% increase in Ks relative to control.
found when soils were treated with vermicast in a size As the size of vermicast decreased (<0.5 mm), the
range of 1.0 – 2.0 mm. Ks generally reduced relative to control in sandy loam
On the other hand, the lowest Ks was observed in soils. The lower Ks due to the addition of fine-sized cast
sandy loam soils treated with <0.5 mm-sized vermicast could be ascribed to the presence of a greater surface
at all the different application rates. The incorporation of area by which hydrated counterions were absorbed. A
35
1.0 – 2.0 mm sized vermicast caused 37.50%, 100.0%, similar scenario was observed for loam soils, except for
and 93.10% higher Ks compared to the respective lowest those with 15 t/ha incorporation. Yılmaz and Alagöz
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Volume 22 Issue 1 (2025) 118 doi: 10.36922/ajwep.7526