A two-year field study published in the Eurasian Journal of Soil Science confirms that applying corn straw biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More significantly improves both the chemical properties and microbial activity of Chernozemic soil. Conducted by Tolulope Yetunde Akande, Toluwase Oreoluwa Adegoke, and Hongyan Wang, the research addresses the need to restore the fertility of these highly valued soils in Northeast China, which have suffered degradation from intensive farming. The study, which applied biochar at three doses—a control ( BC0), a medium dose (BC15) of 15 t ha−1, and a high dose (BC30) of 30 t ha−1—found that the highest dose delivered the most robust and lasting benefits across all measured parameters. The positive effects began immediately and persisted into the second year, despite no additional biochar application.

Specifically, the highest dose of 30 t ha−1 significantly increased soil organic carbon (SOC) compared to the control (BC0) in both the upper (0-15 cm) and lower (15-30 cm) soil depths. In the first year, SOC in the 0-15 cm depth increased from the control’s 17.51 g kg−1 to over 22 g kg−1 with the BC30 treatment. This highlights biochar’s ability to build the soil carbon pool. The addition of biochar also significantly improved the availability of major plant nutrients. The high dose ( BC30) relatively increased available nitrogen (AN), available phosphorus (AP), and available potassium (AK) in both 0-15 cm and 15-30 cm soil depths during both years, performing better than the medium BC15 dose. For example, in the first year, BC30 significantly increased AP concentration in the 0-15 cm soil depth compared to the lower BC15 dose and control. This improvement stems partly from the essential nutrients already contained in the corn-straw derived biochar, which was found to have nutrient contents of 1.57% available nitrogen, 1.89% phosphorus, and 1.32% potassium.

The large surface area and high porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More of the biochar are also believed to improve nitrogen retention in the soil by providing crucial adsorption sites. Beyond nutrient chemistry, biochar fostered a more active biological environment. The treatments resulted in considerable increases in the soil microbial biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More pool, including microbial biomass carbon (MBC), nitrogen (MBN), and phosphorus (MBP) in both soil layers and across both years. In the first year, for microbial biomass carbon in the 0-15 cm depth, BC15 and BC30 statistically surpassed the control. This increase in the microbial biomass is believed to be accelerated by the presence of biochar in the soil, which provides a more suitable environment and a carbon source for microbial activities, ultimately retaining nitrogen and enhancing phosphorus turnover. The study also tracked changes in soil pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More. The biochar, which had a pH of 10.09, caused a clear increase in soil pH in the first year compared to the control, especially in the 15-30 cm depth where a significant increase was observed. This effect aligns with prior studies that report biochar’s ability to increase pH due to its alkaline ashAsh is the non-combustible inorganic residue that remains after organic matter, like wood or biomass, is completely burned. It consists mainly of minerals and is different from biochar, which is produced through incomplete combustion.   Ash Ash is the residue that remains after the complete More content. However, the pH effect did not remain statistically significant in the second year across all doses and depths, suggesting this chemical buffering effect may be less persistent than the increases in organic carbon and microbial biomass.

Overall, the findings strongly support the use of a high dose of corn straw biochar (30 t ha−1) as a credible practice for the restoration of soil health in Chernozemic soils. The positive modifications to soil chemistry and microbial activity promise long-term benefits for agricultural sustainability and productivity in the region.

Source: Akande, T. Y., Adegoke, T. O., & Wang, H. (2025). Biochar application enhances soil nutrient availability and microbial biomass in Chernozemic soil. Eurasian Journal of Soil Science, 14(3), 280-289.