Farmer Steve Groff of Holtwood, Pa., is an enthusiastic advocate for the use of cover crops in both no-till and conventional tillage farming methods. In fact, he worked for over 10 years with Dr. Ray Weil at the University of Maryland to develop and bring to market the Tillage Radish cover crop, a variety of the brassica species, selected for its uniquely aggressive single taproot that grows through compacted soils and provides many additional benefits.
Groff operates what many experts consider as one of the most extensive on-farm cover crop research farms in the nation. His Cedar Meadows Farm covers 215 acres in Southeast Pennsylvania, just a few miles north of where the Susquehanna River empties into the Chesapeake Bay.
In a new research finding in the use of cover crops, this past year, Groff grew 190 bushel per acre corn on farm-scale plots without the addition of Nitrogen fertilizer. For a nitrogen hungry crop like corn, such results are virtually unheard of in the agricultural arena.
His annual Cover Crop Field Days attracted hundreds of farmers, scientists and environmental proponents to see first hand how cover crops are used to virtually eliminate soil erosion, reduce the use of all types of pesticides, enhance soil biology and actually increase yields in the process. In fact, University of Maryland research, in which Groff participated, showed that the use of the Tillage Radish increases corn yields by 12 bushels per acre (bu/ac), soybean yields by eight bu/ac, and winter wheat yields five bushels per acre and more in some cases.
The tests were replicated in fields that have been continuously no-tilled for 18 years. The test fields were seeded in August 20, 2010 with a 10-species mix of cover crops. TA Seeds variety TA525-13V (103 day) corn was planted April 29, 2011. No starter or N was applied. Other plots in the fields receive 60, 90 and 120 lbs of N at sidedress. The harvest was measure by TA Seeds' weigh wagon.
The zero-nitrogen fertilizer input and high corn yield is attributed to the sustained use of no-till practices over time as a means to build soil health, combined with nitrogen fixing cover crops. Groff's research shows that strategically selected blends of the Tillage Radish, legumes like Austrian Winter Peas, and soil-building plants like Phacelia and others can dramatically reduce or, in some cases like this research finding, replace the need for additional fertilizer input altogether.
Groff's fields teem with earthworms, a recognized sign of healthy soil, where air and water infiltrate with ease, and where microbial populations are in balance with the plant life that the soils sustain. In fact, where Tillage Radish is planted as a fall cover crop, earth worms are attracted to them like a magnet, feed on them as they decompose in the spring and take their collected nutrient benefits deep into the root zone of the follow row crops.
Beneficial fungi like Mycorrhiza are abundant in healthy soils, as well as beneficial insects and other life forms. Cover crops help restore soils in intensively cultivated agricultural fields such that the soil-depleting effects are largely offset. Interest is rapidly growing in knowledge about the regular use of cover crops planted after and before, and in some cases interseeding with cash crops like corn, soybeans, wheat and cotton. Properly selected cover crops can double as additional forage value for cattle.
Groff's dedication to farm-based research is helping produce the kind of economic data and other practical information that farmers need to more readily adopt the regular use of cover crops as part of their cultivation program.