Biochar-mediated improvements in soil health in drylands: A bibliometric review of the potential and mechanisms for combating desertification and climate change

Abstract

Climate change has increased the vulnerability in dryland regions, which are more often facing challenges associated with water scarcity and low crop yields. In this context, sustainable soil management practices are a valuable tool to enhance the resilience of these areas as they can provide environmental benefits while ensuring fiber and food production. Among these practices, biochar use has gained recent attention due to its potential to enhance soil health; however, there is a lack of studies that synthesize the existing published data to guide future research. Therefore, we performed a bibliometric review to assess the current research status of soil health studies on biochar use in dryland soils. A total of 38 documents published between 2013 and 2024 were selected from the Web of Science and Scopus databases to be included in our analysis. Our results show that China leads in the number of publications, followed by Pakistan and Iran, which highlights the existence of research gaps in sub-Saharan Africa, Latin America, and parts of the Middle East and Europe. The most commonly evaluated properties in these studies to assess soil health were pH and phosphorus for chemical-associated parameters, and soil organic carbon and bulk density for biological and physical attributes, respectively. Physical parameters were the least commonly evaluated by the soil health studies with biochar application in drylands, despite their relevance. Research in the area highlights the overall potential of biochar to increase key parameters associated with land conservation in dry areas, such as nutrient availability, water retention, carbon sequestration, and crop productivity. However, research conducted on this matter remains limited and unevenly distributed. We recommend that future studies should address regional gaps and explore long-term effects under field conditions to enhance the current understanding of the benefits associated with biochar use in drylands.