Planting Green and Soil Health the Focus of June Field Day

Planting green is a practice where cover crop termination is delayed until cash crop planting in order to extend soil health benefits longer into the season.
Planting Green and Soil Health the Focus of June Field Day - News


A crowd gathers at a farm in Clinton County to discuss opportunities for managing soil health and planting green.

Successful no-till cover cropping often requires management and equipment modifications to address challenges that occur when managing cover crop residues, soil moisture, and in some years, slugs. Some growers use a tactic called "planting green" in order to overcome some of these challenges. Planting green is a practice where growers delay cover crop termination until cash crop planting. Instead of killing the cover crop 1-2 weeks ahead of cash crop planting, the cover is allowed to grow longer into the spring, which can also extend soil conservation and health benefits provided by the cover crop. Considerable interest by growers and researchers prompted an interdisciplinary research project led by Heather Karsten, Bill Curran, John Tooker, Sjoerd Duiker, and Ron Hoover to evaluate planting green with corn and soybeans across a range of farms in Pennsylvania. Since 2015, Agronomy PhD student Heidi Myer has been evaluating delaying cover crop termination at two Penn State research farms (Rock Springs and Landisville) and three cooperating farms in Centre, Clinton, and Lancaster Counties.

On Thursday, June 22, 2017, 80 producers, agency, industry, extension, and non-profit personnel gathered at the Myers Farm in Spring Mills, PA to discuss the fundamentals and current Penn State research regarding soil health, planting green, and interseeding cover crops.

Joel Myers, member of the PA No-Till Alliance, retired NRCS state agronomist and partner of Myers Farm kicked off the day by introducing the attendees to the farm history, philosophy, and crop rotations. Joel proudly explained that he and brother Don have "never-tilled" for over 30 years, while primarily growing cash grain soybeans, small grains, and forages for sale to local dairies. Myers has collaborated with Penn State for several research projects over the years, including the planting green project (2015-2017). Myers focuses heavily on managing soil health, and aims to keep living cover on the soil for as much of the year as possible; by using perennial forages, cover crops, and planting green, he does just that.

Kristy Borrelli (Penn State Extension Educator) dug deeper into soil health, discussing that best management practices (BMPs) like reduced tillage, diverse crop rotations, nutrient management, and maintaining living cover on the soil, work to improve soil health and productivity by adding various sources of organic matter to the soil. The significant role of soil organic matter in these functions prompted Borrelli to note the importance of using multiple practices in a field, while also testing soil for organic matter at the same time of the year, every couple of years, to monitor how BMPs are influencing the soil.

Heidi Myer then summarized what the planting green research team has learned since its start in 2015. Myer cautioned against planting green in a dry spring (like 2015) since cover crops allowed to grow longer dried the soil excessively and cash crop planting depth, and in some cases populations were reduced. At all site-years, when planting green was used, soil temperatures were cooler and soil was drier at crop planting, resulting in delayed cash crop emergence and maturity. Later in the season, however, the late terminated cover crop residue conserved more soil moisture than cover crops that were terminated earlier in the season. Myer also emphasized that growers interested in trying planting green for the first time start with the more adaptable and forgiving soybeans, and save corn for when they have more experience with managing heavy residue and equipment settings, and when weather and field conditions are the more favorable. Myer noted that slug feeding on cotyledon stage soybeans has been reduced when soybeans were planted green compared to into an early-killed cover crop, but the influence of planting green on slugs in corn has been mixed. Another challenge with corn when planting green is nitrogen management, as N tie-up by large, mature covers and slowed N-cycling due to colder soils could be problematic.

A lunchtime panel discussion allowed growers to ask questions of several farmers with planting green experience, and to learn from their experiences--both successes and failures. The field day drew attendees from at least 12 counties and from as far as Northern Maryland, all with different experiences with cover crops and planting green. Growers highlighted strategies to manage cover crop biomass by adjusting cover crop seeding rates and modifying crop planters with aggressive row cleaners and/or cover crop roller-crimper units to improve cash crop establishment. The animated information exchange was educational for producers, agency and extension personnel, and researchers alike.

To round out the day, John Wallace (Penn State postdoctoral scholar) shared practical programs for burning down covers when planting green and Ron Hoover (Penn State Extension on-farm research coordinator) showed a Penn State interseeder and summarized some recent on-farm interseeder research. Interseeding enables establishment of cover crops early in the corn growing season instead of waiting until after harvest. Interseeders can also be equipped with liquid-handling equipment to facilitate side-dressing N and/or to apply a post-emergent herbicide to growing corn. Hoover noted that interseeding at corn stage V5 to V-6 has resulted in good cover crop establishment with no loss in corn yield in the medium and shorter-season corn growing areas. However, in the longer season corn growing areas, it appears that interseeding a little earlier (V-4) is necessary to allow the cover crop to become better established to withstand the longer periods of shade and higher temperatures in southern and southeastern PA counties. Wallace contributed considerations for managing weeds without harming cover crops, noting that interseeding multiple cover crop species will complicate the herbicide program.

A special thanks to the hosts of the event, Joel and Don Myers; to Centre and Clinton County Conservation Districts and PA No-Till Alliance for help with organization and advertisement, and to all whom contributed to the panel and field day discussions and to the USDA Northeast Sustainable Agriculture Research and Education grant for funding the field day.