Testing of nutrient transport equations developed for upland areas

Authors: Gilley, John

Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/17/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary: A previously reported study was conducted to identify mechanisms influencing nutrient transport on upland areas. The present exercise was performed to make predictions based on the previously formulated hypotheses and to then test the accuracy of the predictions. The slope of linear equations relating phosphorus (P) transport rates to runoff rates can be estimated from the P content of soil. Transport rates for P can be related to runoff rates on sites where swine slurry was applied, or cattle manure had been added at rates < the annual N requirement for corn. On plots where larger amounts of cattle manure were broadcast, the maximum rate at which manure can release P to overland flow can be predicted from the P content of manure. Finally, transport rates for nitrogen (N) can be related to runoff rates on sites containing varying amounts of soil N, beef cattle manure, or swine slurry. Additional experimental data is needed to determine if the maximum rate at which soil or swine slurry can release nutrients to overland flow can be related to the nutrient content of soil or slurry.

Technical Abstract: A previously reported study was conducted to identify mechanisms influencing nutrient transport on upland areas. The present exercise was performed to make predictions based on the previously formulated hypotheses and to then test the accuracy of the predictions. The slope of linear equations relating phosphorus (P) transport rates to runoff rates can be estimated from the P content of soil. Transport rates for P can be related to runoff rates on sites where swine slurry was applied, or cattle manure had been added at rates < the annual N requirement for corn. On plots where larger amounts of cattle manure were broadcast, the maximum rate at which manure can release P to overland flow can be predicted from the P content of manure. Finally, transport rates for nitrogen (N) can be related to runoff rates on sites containing varying amounts of soil N, beef cattle manure, or swine slurry. Additional experimental data is needed to determine if the maximum rate at which soil or swine slurry can release nutrients to overland flow can be related to the nutrient content of soil or slurry.