Planting grass is not a typical task for the U.S. Army Engineering and Support Center, Huntsville. However, when the grass began getting sparse in a mortar and artillery impact area on a steep hillside at West Point, N.Y., Huntsville Center's Ordnance and Explosives Design Center knew how to helped get new grass planted.
There is much more to West Point than just the U.S. Military Academy campus. Cadets there learn to become officers by receiving extensive military training on a large complex of ranges to the south and west of the Academy. Many of the ranges have been used since the Revolutionary War.
The impact area on one range, known as Cranberry Mountain, was pocked with craters from mortar and artillery explosions. Rain and melting snow washed away much of the remaining topsoil, leaving nutrient-poor soil too depleted to keep grass healthy.
Seeking a solution, environmental managers at West Point contacted the U.S. Army Corps of Engineers. Agronomist Tim Cary at the USACE Cold Regions Research Laboratory in Burlington, Vt. and workers at the Army’s Aberdeen Test Center in Maryland colaborated to create seed balls that could be mechanically distributed across the area. Each seed ball contained three different types of grass seed and potting soil to provide fertilizer. The mix was rolled into a ball about 1.5 inches in diameter and then rolled in xanthan gum to form a hard shell that would soften when it got wet, allowing the seeds to spread and germinate.
The concept was simple enough: distribute the seed balls on the hillside, except people are not permitted in the area without special escort due to the risk of detonating unexploded ordnance. A rotary agricultural spreader would do the job, but any tractor used would have to be heavily armored to protect the driver. That challenge was solved by project manager Spencer O’Neal of Huntsville Center’s Ordnance and Explosives Design Center. Contractor Dawson-Zapata and subcontractor Robotics Fabrication had radio-controlled equipment that was already being used on ranges at other Army installations.
The first seeding attempt last year was postponed by Hurricane Sandy, then rescheduled for March. Melting snow made the hillside slick, even for a dozer using caterpillar treads. A narrow path was cut across the hillside, then up the slope. Workers faced a challenge when the dozer blade was removed: the dozer blade used a two-point mounting system, but the spreader was configured for a three-point mount on the back of a farm tractor. Field modifications using angle iron, nuts and bolts solved the problem. The hopper was loaded with seed balls and the dozer was sent remotely into the work area. A mere 15 minutes of the next two hours were required to distribute all 35,000 seed balls: the rest of the time was spent negotiating the slick path for reloading.
One of the seeds, a type of oat, was expected to germinate in about a week with the tall fescue and perennial rye a week later. Plans call for return visits in May and September to check results.