Greenhouse evaluation of biochar to enhance soil properties and plant growth performance under arid environment

Samer Qaraleh, Timothy Coolong, Mohammad Aliedeh, Osama Mohawesh

Abstract: Agriculture production in arid and semi-arid regions face several problems such as soil degradation, water shortage, and chemical toxicity. Soil amendments to improve soil water and nutrient holding capacity have become an important tool to enhance soil properties. Biochar is being suggested as a soil amendment for improving the quality of the agricultural soils. Therefore, pot experiments were conducted under greenhouse conditions using five levels of biochar (0 - control, 0.5, 1.0, 2.5 and 5.0% wt/wt) produced from broccoli residue applied to an alkaline, sandy loam soil to evaluate the effects of biochar on plant growth and performance as well as on soil physical and chemical properties. The results indicated that the growth of tomato (Solanum lycopersicum) and bell pepper (Capsicum annuum) plants were adversely affected by biochar additions at high levels (2.5 and 5.0%). Bell pepper and tomato biomass were not significantly different compared to the control treatment at 0.5 and 1.0% biochar. Biochar applications significantly affected leaf nutrient concentrations in both plants. Proline concentrations increased significantly in bell pepper and tomato with increasing biochar levels. Soil pH and EC values increased significantly with biochar applications. The biochar application to the soil increased soil EC and pH by 35.8 to 192.4% and by 1.6 to 5.5%, respectively, compared to the control treatment. For most measured parameters, the highest level of biochar application (5% wt/wt) adversely affected plant growth and nutrient uptake. Based on the results, biochar may have benefit when used as soil amendments at application levels of less than 2.5% (wt/wt); however, additional studies are necessary to determine the impact of biochar feedstock, pyrolysis conditions, soil type, and growing conditions to better understand the effects of biochar under arid and semi-arid soil conditions.

Keywords: biochar; pyrolysis; soil fertility; sustainable waste recycling; water availability

Date published: 2019-01-04