The Impact of Soil pH on the Carbon and Nitrogen Retention Capacity and Cumulative CO2 Emissions in Microbially Activated, Biochar-Amended Soil

School Name

Spring Valley High School

Grade Level

10th Grade

Presentation Topic

Environmental Science

Presentation Type

Non-Mentored

Abstract

While industry and fossil fuels have greatly contributed to greenhouse gas emissions, the agricultural sector is another major driver, accounting for roughly 21-37% of human-related emissions (Mbow et al., 2022). The purpose of this study was to examine how soil pH influenced CO2 emissions and carbon and nitrogen retention in microbially activated biochar-amended soils. It was hypothesized that an alkaline pH would demonstrate greater carbon and nitrogen retention and lower cumulative CO₂ emissions over 21 days as opposed to acidic or neutral soils, because alkaline conditions are expected to favor microbial colonization of biochar pores and reduced carbon mineralization rates (Wang et al., 2023). To test this hypothesis, biochar-inoculum mixture was added to soil-filled jars divided into various pH levels. CO2 emissions were measured on days 1, 4, 7, 14, and 21. After 21 days, total organic carbon (TOC) and total organic nitrogen (TN) were measured with a soil testing kit. The ANOVA and post-hoc Tukey results supported the hypothesis: the alkaline group had the lowest CO2 emissions, while the neutral group had the highest (F(3, 116) = 42.01, p < .001). TOC and TN values showed that alkaline conditions experienced the highest nutrient retention (χ²(9, 120) = 72.37, p < .001). There is sufficient evidence to suggest that there is a difference in CO2 emissions based on soil pH. The results propose that microbially-activated biochar be instituted in agricultural settings to abate CO2 emissions and improve carbon and nitrogen retention.

Location

Furman Hall 209

Start Date

3-28-2026 11:00 AM

Presentation Format

Oral and Written

Group Project

No

COinS
 
Mar 28th, 11:00 AM

The Impact of Soil pH on the Carbon and Nitrogen Retention Capacity and Cumulative CO2 Emissions in Microbially Activated, Biochar-Amended Soil

Furman Hall 209

While industry and fossil fuels have greatly contributed to greenhouse gas emissions, the agricultural sector is another major driver, accounting for roughly 21-37% of human-related emissions (Mbow et al., 2022). The purpose of this study was to examine how soil pH influenced CO2 emissions and carbon and nitrogen retention in microbially activated biochar-amended soils. It was hypothesized that an alkaline pH would demonstrate greater carbon and nitrogen retention and lower cumulative CO₂ emissions over 21 days as opposed to acidic or neutral soils, because alkaline conditions are expected to favor microbial colonization of biochar pores and reduced carbon mineralization rates (Wang et al., 2023). To test this hypothesis, biochar-inoculum mixture was added to soil-filled jars divided into various pH levels. CO2 emissions were measured on days 1, 4, 7, 14, and 21. After 21 days, total organic carbon (TOC) and total organic nitrogen (TN) were measured with a soil testing kit. The ANOVA and post-hoc Tukey results supported the hypothesis: the alkaline group had the lowest CO2 emissions, while the neutral group had the highest (F(3, 116) = 42.01, p < .001). TOC and TN values showed that alkaline conditions experienced the highest nutrient retention (χ²(9, 120) = 72.37, p < .001). There is sufficient evidence to suggest that there is a difference in CO2 emissions based on soil pH. The results propose that microbially-activated biochar be instituted in agricultural settings to abate CO2 emissions and improve carbon and nitrogen retention.