Physio-mechanical Properties of Biochar Granules

In recent years the sequestration of carbon and its effect on the soil is gaining importance in developed countries to reduce global climate change effects. Biochar application to agricultural soils is viewed as an amendment for carbon sequestration, improve the soil physical properties and increase the efficiency of applied fertilizers. However, application of fine powder biochar is a major concern due to losses as high as 30% at various stages and applicators safety of dust pollution. Thus, granulation process using drum type machine, composed of two types of binder materials with thermal treatment were evaluated. The desirable size range biochar granules has field capacity ranges from 60–94% (db-dry basis) and were non hygroscopic in nature. Prosopis juliflora biochar granules with Carboxymethyl cellulose sodium binder recorded highest bulk density 326 kgm⁻³ and rice starch binder granules 209 kgm⁻³. The granules had less than 10% attrition in presence of similar size harder material. The crushing strength of granules was comparable with that of commercial fertilizer granules. In sandy loam soil application granular bio-char material disintegration rate increased with increase in moisture content upto 17% (db) of medium and need caution at higher moisture contents for proper mixing.