My Current Research

A number of clientele in Delaware may not be aware that I am in the middle of doing my PhD. I thought I would share a summary of a portion of my research work that could benefit the horticulture industry.

The Potential of Former Poultry House Pad Soils for use as Horticultural Amendments

There are over 2400 derelict poultry houses covering 1000 acres that are out of production on the Delmarva Peninsula. Poultry houses are built over soil pads that accumulate mineral nutrients through diffusion from manure in litter over a 30-50 year period. This includes significant amounts of nitrate nitrogen (NO3-N). Once production ceases, houses are often demolished or left to slowly deteriorate. Exposed pads are subject to leaching from rainfall and high amounts of NO3-N can enter the groundwater. Research is underway to study nutrient loading at these sites and methods to recover nutrients, particularly nitrogen (N). Remediation strategies being explored include co-composting of pad soils to create synthetic soils, use of pad soils directly as a fertilizer, using pad soils for enriched topsoil products, and use of salt tolerant plants as bioremediators that would then be composted. Potential uses of these products as horticultural amendments is a part of this research. Challenges include variability in nutrient content at sites, high salt levels, inconsistency in soil particle sizes, and weight of the material.

Gordon Johnson, Extension Agriculture Agent, UD, Kent County