Effect of Biochar Type, Particle Size and Application Rate on Some Physical Properties in a Silty Clay Loam Soil

Document Type : Research Paper


Department of Soil Science, College of Agriculture, Shiraz University, Shiraz, Iran



Biochar application has been proposed as a suitable amendment way of soil properties to sustainable agriculture. However, the effect depends on biochar application and soil properties. The purpose of this study was to investigate the sole and combined effects of different sources, rates and particle size of biochar on soil bulk density, aggregate stability, penetration resistance and shear strength in a silty clay loam soil. Palm leaf and lemon peel biochar prepared at a pyrolysis temperature of 500∘C with three particle sizes 2–4, 0.8-2 and smaller than 0.8 mm, mixed in soil at application rates 0, 0.5, 1, 2 and 4 % (by weight). After 15 months (2019 to 2020) incubation at standard condition in research glasshouse of faculty of agriculture Shiraz University, soil properties analyzed by standard methods. In general, the applied biochar had significant effects (P<0.01) on decrease soil bulk density, penetration resistance, and shear strength and increase aggregate stability as compared to control. Palm leaf biochar played better roles in improving soil properties as compared to lemon peel biochar. On average, by increasing biochar rates to 4%, decreased soil bulk density by 14.5 %, penetration resistance by 85 %, Shear strength by 59.8 % and increased aggregate stability by 50.5. The grate effects of biochar were achieved at particle size smaller than 0/8 mm for aggregate stability and penetration resistance. Bulk density and tension strength did not considerably change by use different particle size biochar. Base results, by choosing the appropriate particle size and application rates of each sources of biochar can be achieved the best performance in improving the soil physical properties.


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