In a recent publication in AgriEngineering, researchers Emilio Suarez, Hayley Milner, Juan Carlos Diaz Perez, Kate Cassity-Duffey, Henry Y. Sintim, and Theodore McAvoy evaluated sustainable agricultural strategies designed to bolster soil health indicators in coarse-textured soils. Cultivating sweet corn in the highly weathered soils of the southeastern United States, specifically the coastal plain regions of southern Georgia, presents prominent management challenges due to low natural organic matter, high soil acidity, poor water retention, and limited infiltration capacity. While wood-derived charred biomass and organic poultry waste are frequently promoted as beneficial soil amendments to overcome these physical and biological constraints, their short-term interactions under variable field conditions have remained inconclusive. To establish clear benchmarks, the scientists monitored a bareground production system over two consecutive growing seasons, tracking physical, chemical, and biological variations across the soil profile.

The comprehensive field trial examined five distinct application volumes of the organic charcoalCharcoal is a black, brittle, and porous material produced by heating wood or other organic substances in a low-oxygen environment. It is primarily used as a fuel source for cooking and heating.   More byproduct alongside both commercial synthetic compounds and natural broiler waste treatments. Statistical analyses revealed that the short-term addition of the pyrolyzed biomass did not cause significant changes in vital physical or chemical metrics, including structural block aggregate stability, soil acidity, cation exchange capacity, soluble salts, or organic matter content. For instance, the calculated cation exchange capacities across all test plots remained statistically identical, varying only between 4.22 and 4.83 centimoles per kilogram despite heavy charcoal additions. Furthermore, the overall acidity levels and active carbon pools did not shift in response to the increasing charcoal rates, indicating that the baseline properties of the sandy loam remained highly resilient to short-term structural amendments during the initial two years of exposure.

In contrast to the uniform responses observed with the charred biomass, the choice of fertilizer amendment produced clear differences in soil biological activity. The application of uncomposted poultry litter resulted in a significant increase in microbial respiration rates, measured via standard carbon dioxide burst testing, when compared directly to the plots treated with inorganic granular fertilizers. This elevated biological breathing indicates that the organic waste successfully stimulated local microbial populations by providing readily available carbon and nutrient streams. However, other essential parameters, such as the estimated nitrogen mineralization values and soluble salt concentrations, remained broadly similar between the two distinct fertilizer categories, suggesting that either input can support standard crop nutrition profiles.

The dominant factor driving overall soil health variation throughout the two-year timeline was the pronounced inter-annual climate variability rather than the deliberate management practices. The experimental site experienced extreme weather deviations during the second growing season, including frequent downpours that accumulated 572 millimeters of total rainfall, which exceeded the historical regional normal by nearly 175 millimeters. These severe weather events led to visible topsoil displacement, surface erosion, and severe crop lodging. Consequently, this heavy moisture influx caused a twenty-eight percent reduction in soil aggregate stability and a fourfold decrease in soluble salts due to intense field leachingLeaching is the process where nutrients are dissolved and carried away from the soil by water. This can lead to nutrient depletion and environmental pollution. Biochar can help reduce leaching by improving nutrient retention in the soil.   More, while simultaneously triggering an increase in baseline organic matter and active carbon parameters. Ultimately, the investigation highlights that environmental disruptions exert a far greater short-term impact on coastal agricultural systems than proactive soil amendments.

Source: Suarez, E., Milner, H., Diaz Perez, J. C., Cassity-Duffey, K., Sintim, H. Y., & McAvoy, T. (2026). Biochar and fertilizer type effects on soil health indicators in a sandy loam Ultisol of the Georgia Coastal Plain: A two-year field study. AgriEngineering, 8(7), 293.