A “fevered pitch” may be a bit hyperbolic a description for technology advances in biosolids stabilization. A review of the agenda at recent conference will reveal a swing toward advanced digestion and chemical treatment processes to improve pathogen destruction, biogas production, and odor reduction. Yet, articles on our fundamental mission area, land spreading of biosolids, have almost disappeared. So it is a good thing to read that breakthrough new approaches are being studied for delivering solid byproducts to soil for crop fertilization in new ways.
Those of us engaged in biosolids application to farm fields have shared some concern for the uneasy relationship between agricultural practices associated with no-till and conservation tillage and the use of biosolids. No-till farming achieves the protection of soil structure and soil infiltration capacity, but at the expense of reliance on aggressive chemical weed control. Biosolids on such no-till fields may be surface applied, as are manures in the same practice, but with the risk that nutrients and organic matter might be carried to surface waters during heavy storm events.
The drive to address the issue of solid manure spreading while minimizing risk of environmental releases has been focused in sensitive watersheds, notably those within the Chesapeake basin. The drive has produced innovation. And reports of successful new approaches are now being released.
A recent JEQ article (see; https://www.soils.org/publications/jeq/articles/40/2/287) discusses novel manure application methods to reduce N and P losses in no-till systems of agriculture. This article introduces the positive qualities of a new subsurface applicator for poultry litter, which is the first subsurface applicator available for solid manures. The biosolids profession should be among early adopters of equipment that advances the goal of reduced nutrient losses while conserving soil structure.