Injecting Manure (IMAGE) Penn State Caption The dairy cropping-systems trial uses injected manure to supply nitrogen to the forage, feed, and fuel crops raised on the farm. Credit Robert Meinen, Penn State Usage Restrictions Non commercial use only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.