Cover Crops 2 (IMAGE) Penn State Caption Two views of cover crops mixture research sites at Penn State's Russell E. Larson Agricultural Research Center. In the University's experimental plots, researchers manipulated cover crop expression with nitrogen inputs and planting dates to learn response of the various species to soil conditions and growing days. These photos show that flowering canola overtook the mix. Credit Barbara Baraibar, 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.