Characterization of biochar and its effects on the water holding capacity of loamy sand soil: Comparison of hemlock biochar and switchblade grass biochar characteristics

Abstract

Two of the most important resources in agriculture are soil and water. The quality of the soil determines the health and output of crops. Biochar has been recognized as being a useful soil amendment due to its perceived benefits of increasing water and nutrient retention. However, limited research has been conducted to compare the characteristics of biochar created from different feedstocks to determine which are the most effective at raising water holding capacity. This study compared the water holding capacity and chemical composition of biochar created from two different materials: eastern hemlock and switchblade grass. Results showed that both the hemlock char and switchblade grass char were able to significantly raise the water holding capacity of loamy sand. The switchblade grass increased the water holding capacity more than the hemlock biochar. For example, at a mixture rate of 10% biochar by weight, switchblade grass increased loamy sand's water holding capacity by 228%, compared with 133% for hemlock. The water holding capacity of the switchblade grass biochar alone was 448.69% of its weight and the hemlock biochar held 268.34% of its weight. These results suggest that switchblade grass may be better suited for improving water retention in sandy soils. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1474–1479, 2017