Evaluation of Interseeded Cover Crops in Southeastern PA for Winter Biomass Crop Production Potential, Soil and Nutrient Conservation

Corn grain is frequently not harvested until late fall months and cover crops are often not planted due to poor conditions for successful establishment: low temperatures and short days. The cover crop interseeder, developed at Penn State, is a specialized no-till drill that plants cover crops between established corn rows, that may allow for production of a winter biomass crop for anaerobic digestation. In Southeastern PA cover crop interseeding has not been limited compared to central and northern regions. One hypothesis is that the longer season corn hybrids are more competitive in the SE PA, and planting the cover crops earlier in the corn might improve establishment. We identified three commercial farms in Southeastern PA interested in trying the cover crop interseeder. We compared interseeding annual ryegrass (Lolium multiflorum L.) and clovers into corn grain, to planting cereal rye (Secale cereale L.) after corn grain harvest in six replicated side-by-side field strips. We measured corn yield, and ground cover of cover crops and weeds at the end of the first growing season. In the subsequent spring, we measured: i. cover crop ground cover, ii. cover crop biomass, and iii. soil nitrate to assess if the cover crop treatments reduced soil nitrogen concentration. Due to an exceptionally dry spring, interseededing of the cover crops was delayed from V4 to V5 on two farms and the interseeded cover crops only established well on one of three farms. Only one commercial farm participated in the study for a second year where the interseeded crop establishment was poor. Very dry weather and soil conditions limited interseeded cover crop establishment in the first year and our ability to recruit farms to assess its performance in the second year.