Last year, American Agriculturist reported on an innovative nutrient runoff test underway at University of Maryland's Wye research center. Preliminary findings suggested that sediment, nitrogen and phosphorus runoff losses from poultry litter were substantially higher for no-till than for three conservation tillage measures – turbo till, chisel and disk, and strip till.
This summer's results for sediment and nitrogen losses at the site were very similar, despite less than normal rainfall, acknowledges Joshua McGrath, University of Maryland Extension agronomist. The no-till N loss in the first runoff event was only 4 pounds per acre – on only a 2% slope. However, he adds, "That first rainfall event is most critical for controlling nutrient runoff. Incorporation of poultry litter greatly reduced N losses."
The results have led to expanded trials on six farms in Delaware, Maryland and Virginia with Virginia Tech and University of Delaware cooperating. And similar trials are also underway by Ohio State.