Vermicompost Quality and its Variation on Changes in Moisture Content

Abstract

The Government of Nepal has developed quality standards for soil-amending organic products, including vermicompost. There has been considerable debate on moisture content vis-à-vis quality parameters of commercial vermicompost. This research addressed a pertinent issue for commercialization and quality control of vermicompost by assessing changes in nutrient content upon reducing moisture in ready-to-sale products. Vermicompost samples were collected from ten commercial farms in Kathmandu Valley, Pokhara, Chitwan and Syangja at three stages of production. Samples from the marketed stage (Stage 3) were laid out in a Completely Randomized Design in trays with three replicates and dried under ambient laboratory conditions during winter. Sampling was done at different stages of moisture reduction and physico-chemical parameters were assessed. Reduction in moisture content significantly increased nitrogen content (from 1.06% to 1.46%) but there was, however, significant variation in all tested parameters among products. Phosphorus and potassium content remained unaltered upon reducing moisture to 25%. Under ambient conditions, it took 28 days on average to reduce moisture from 54.28% to 25%, though this depends on prevailing climatic conditions.