Physicochemical and Microbiological Analysis of Vermiwash as an Ecofriendly Soil Conditioner

Abstract

The continuous use of chemical fertilizer is a leading cause of soil contamination and hence adversely affecting biodiversity. A more suitable alternative to these chemicals are natural organic fertilizers. One of these is vermiwash, a liquid plant growth promoter known to bring about growth enhancement in a wide variety of plants. Vermiwash is a brown colored, odorless, liquid biofertilizer which is collected after it passes through a column of worm culture. It is considered as a storehouse of nutrients and microorganisms and used as a foliar spray for crops. This work was carried out to study the microbiological and physicochemical properties of vermiwash of Eisenia foetida and its application. Vermiwash was produced in a 100 L barrel by adding pre-decomposed municipal wastes along with cow dung (3:1 ratio) and composted with E. foetida. The product was collected at regular intervals of 5 d up to 15 d and subjected to various assays. Higher number of bacteria, and fungi, such as Acromobacter (1.023 × 103), Azatobacter (1.04 × 103), Bacillus baccilli (1 × 103), Bacillus subtillus (1.05 × 103), Micrococcus sp (1.02 × 103), Pseudomonas sp (2 × 103), Actinomycetes (1.24 × 103), and fungus (1.8 × 103) CFU/mL were found in the collected liquid. Nutrients such as nitrogen, phosphorous, potassium, sodium, iron, zinc, and manganese were also found in significant amounts due to earthworm activity. Field trials on Capsicum annum and Lycopersicum esculentum resulted in their enhanced growth. Hence, the high nutrient profile and microbial diversity of the vermiwash makes it a more suitable biofertilizer for enhancing plant growth and soil health.