Effect of Rice Husk Biochar on Some Physical Characteristics of Soil and Corn Growth in a Loamy Soil

In the last decade, the use of biochar as a soil amendment has been of interest to researchers. Many researchers have conducted studies on the effects of biochar on soil physical and chemical properties. The purpose of this study was to investigate the effect of rice husk biochar on some physical characteristics of soil and corn growth. For this purpose, experimental pots with three replicates were filled with a mixture of loamy soil and three levels of biochar: zero (control), 2% and 4 % (wt). The pots were planted to seed corn cv. Single Cross 704 and studied for three months. Rice husk biochar was produced at a temperature of 500 °C during the pyrolysis process in an electrical furnace. The physical properties of soils were measured after plant growth period. Data collection on plant height was done weekly. Root expansion was also evaluated at the end of the growth period. The results showed that biochar application improved soil physical properties by decreasing soil bulk density, increasing saturated hydraulic conductivity, increasing porosity, and increasing the amount of available water in soil. The height of the plant in the ninth week of growth period was 85 cm in the soil containing 4% biochar, significantly higher than 75 cm in the control soil. The shoot dry weight in 2% and 4% biochar was 154. 7 and 156. 8 g, respectively, which was significantly higher than the control (148. 8 g). No significant effect was observed in root surface, root dry weight, root diameter and root length. In general, it can be concluded that the addition of biochar causes changes in some physical properties of the soil such as bulk density, porosity, water content of the soil as well as saturated hydraulic conductivity. Also, the results showed that increasing the level of biochar application from 2% to 4% would have more potentially positive effects in the soil. Performing larger-scale experiments will definitely help to confirm the findings of this study. It is also necessary to investigate the effects of long-term biochar in soil.