Behavior of Biochar on Alkaline Soil and its Impact on Tomato Growth and Productivity

Abstract

Biochar is projected as a soil conditioner to amend soil physical and chemical properties. However, behavior of biochar in alkaline soils under arid and semi-arid conditions in Egypt not much investigated. In this study, field experiments were carried out under greenhouse conditions to explore the effect of applying biochar and sugarcane bagasse with two different ways and at three different rates (10, 20 and 30 ton ha-1) on some properties of alkaline clay loam soil and tomato growth and yield. The experiments were conducted for two successive seasons of 2015 and 2016. Mixing biochar with top surface soil at rates of 20 and 30 ton ha-1 reduced particle and bulk density and increased the porosity and water holding capacity. The results indicated that biochar application did not affect soil pH, however, decreased ECe and increased soil organic carbon, exchangeable cations and cation exchange capacity. Addition of biochar by mixing through the top-twenty-centimeters of soil surface was more effective than applying as a thin layer under the top-twenty-centimeters of soil surface on improving tomato growth. Application of organic residues such as sugarcane bagasse caused limited positive effects on soil physical-chemical properties. In comparison, this shows the benefit effect of pyrolysis for organic residues on soil properties. Tomato growth and yield only was affected significantly (P < 0.05) by biochar application at a rate of 20 ton ha-1.