Organic waste recycling by vermicomposting amended with rock phosphate impacts the stability and maturity indices of vermicompost

Figures & data

Table 1. Chemical characteristics of substrate used for composting.

Chemical Characteristics	Household waste	Organic residue	Cow-dung
pH	7.35	7.19	8.55
EC (ds m^−1)	2.41	0.93	1.41
Total Organic Carbon (%)	47.3	44.7	22.1
Total nitrogen (%)	2.46	0.57	0.58
Total phosphorus (%)	0.21	0.13	0.26
Total potash (%)	2.39	1.07	0.78
Total Iron (mg kg^−1)	1191	998	1067
Total Copper (mg kg^−1)	16.0	12.0	24.9
Total Manganese (mg kg^−1)	99.6	51.9	349.5
Total Zinc (mg kg^−1)	141.2	51.7	92.9

Figure 1. Effect of substrates and enrichment technique used in vermicompost preparation on water holding capacity and bulk density with the progression of period.

Figure 2. Effect of substrates and enrichment technique used in vermicompost preparation on pH and electrical conductivity with the progression of period.

Figure 3. Effect of substrates and enrichment technique used in vermicompost preparation on cation exchange capacity with the progression of period.

Table 2. Nutrient composition of the vermicompost prepared from different materials.

	N	P	K	Zn	Fe	Cu	Mn
Prepared vermicompost	%			mg kg^−1
Organic residue + Cow-dung + Earthworm	1.86a	1.07a	1.28a	150a	1392a	24a	303a
Organic residue + Cow-dung + Earthworm + Rock phosphate	1.87a	2.35b	1.29a	159a	1466a	25a	320a
Household Waste + Cow-dung + Earthworm	2.14b	1.24a	1.33a	161b	1483a	25a	384b
Household Waste + Cow-dung + Earthworm + Rock phosphate	2.15b	2.55b	1.35a	167b	1509a	26a	407b

Note. Same letter denotes significant similar at P = 0.05 using DMRT.

Figure 4. Effect of substrates and enrichment technique used in vermicompost preparation on water-soluble carbon and water-soluble carbohydrate with the progression of period.

Figure 5. Effect of substrates and enrichment technique used in vermicompost preparation on total nitrogen, total organic carbon, and C:N ratio with the progression of period.

Table 3. Maturity and stability indicators of vermicompost.

Prepared vermicompost	Units	Organic residue + cow dung + earthworm	Organic residue + cow dung + earthworm + rock phosphate	Household waste + cow dung + earthworm	Household waste + cow dung + earthworm + rock phosphate
Maturity indices
WSC	%	1.23b	1.25b	1.05a	1.08a
WSCHO		0.35a	0.37a	0.34a	0.36a
TN		1.86a	1.87a	2.14b	2.15b
TOC		33.70a	35.04a	34.12a	35.76a
C/N ratio		18.12a	16.46a	18.20a	16.75a
Stability indices
CO2 evolution	mg g^−124 hr ^−1	26.41a	26.63a	27.43a	28.36a
Dehydrogenase	μg TPF g^−1 soil h^−1	10.49a	10.97a	11.12a	11.66a
Alkaline Phosphatase	μg PNP g^−1 h^−1	557a	607b	658c	674c

Note. Same letter denotes significant similar at P = 0.05 using DMRT.

Figure 6. Effect of substrates and enrichment technique used in vermicompost preparation on biodegradability index, and population of earthworm with the progression of period.

Figure 7. Effect of substrates and enrichment technique used in vermicompost preparation on enzyme activity with progression of period.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.