Agricultural engineers and USDA’s Agricultural Research Service in Clay Center, Neb., map the distribution of manure on the surface of feedlots and the flow of liquid manure in rain runoff.
This research could lead to both precision harvesting of manure and also precision application of manure to crop fields, while controlling nutrient losses, gas emissions, and odors.
The scientists map manure distribution by slowly towing a GPS-equipped conductivity meter over feedlot pens and cropland. The meter estimates the amount and quality of manure in various places on the feedlot surface by measuring the manure’s ability to conduct electricity. Manure contains salt from feed supplements. Salt, in solution, is an excellent conductor of electricity.
Photo: Agricultural engineers Roger Eigenberg (left) and Bryan Woodbury evaluate a soil electrical conductivity map of a vegetative treatment area. Photo by Stephen Ausmus.