Fate And Transport Of Agricultural Nutrients In Macro-Porous Soils

The major objective of this study is to address water quality problems associated with application of liquid manure to subsurface-drained agricultural lands. There are over 600 large and medium sized confined animal feeding operations (CAFOs) in New York, most of which utilize land application to manage this waste stream. Due to the regions shallow soil and humid weather, most fields have been equipped with tile drainage. The concern is that handling the manure in a liquefied state may enhance the likelihood of contamination of the tile drainage discharge and its potential impacts on downstream water quality. Laboratory studies were used to investigate how manure liquidity (percent solids) affects the transport of manure constituents through the soil. Soil columns were constructed, subjected to simulated rainfall. Effluent samples were analyzed for soluble reactive phosphorus (SRP). As expected, results show enhanced SRP transport through macropores with decreasing percent solids (i.e., more liquidy manure)