As both Grounds Manager and Sustainability Coordinator, I’m always looking for safer and Earth friendlier techniques for maintaining Haverford College’s Grounds. Last January I attended the NOFA (Northeastern Organic Farming Association) Organic Land Care Accreditation Course at the Pennsylvania Horticultural Society. NOFA’s overriding philosophy is to first do no harm. “Every land decision we make has either a positive or negative effect on the land in our care.” While farming was NOFA’s original focus, it has expanded to include all facets of our natural environment.
Over the last year, Haverford has been implementing some of NOFA’s principles when it comes to turf. Turf, or grass to most, is the most commonly used ground cover. In their natural state, common turf grasses mature at 12-18 inches. Center campus is mowed at 3 inches, athletic fields at 2 inches. Combine that with compaction from thousands of footsteps per day, the occasional truck or golf cart and cleats from sports teams, it can create a stressful situation for any plant. Turf weeds on the other hand love compaction. You can tell the condition of the soil just by identifying the weeds growing there. Plantain loves a compacted moist soil while crabgrass favors hot and dry compacted soil. Soil, or dirt to the uniformed, is the key to healthy plants. “Feed the soil, not the plant.” A healthy soil needs less fertilizer and water and can reduce or eliminate the need for pesticides.
Haverford tackles this on a variety of different fronts and varying degrees. First, and possibly the most important, is soil biology and testing. Soil is living, it’s made up of bacteria, fungi, protozoa and earthworms all working together. Haverford has always done standard testing for pH, micro and macro nutrients and organic matter, but recently we’ve also selected pilot areas where we’re testing the soil biology as well. We’ve also been taking soil profiles to see the extent of turf grass root systems.
Aggressive aerification and over seeding is done in both spring and fall. Aerification is either done with a seedevator, a machine that shatters the top couple inches and drops seed or with a core aerifier, an attachment that pulls a four inch plug. Both machines allow air to get to the roots and alleviates compaction. 6,500lbs of grass seed was put down in 2013, the less bare ground, the less opportunity for weeds, the less pesticides need to be used. Aerification also keeps the thatch layer down. Thatch is a mat of un-decomposed plant material. Excessive thatch can cause disease and pest problems in turf grass as well as interfere with grass rooting.
Currently, Haverford uses an all organic fertilizer made up of chicken manure in the majority of it’s turf areas. Organic fertilizers have several benefits over synthetic fertilizers, the main one being it doesn’t require fossil fuels(oil) to produce. As they break down they also add organic matter which aids the soil structure and its ability to hold nutrients, water and air. You also have less salts in organic fertilizers. Synthetic fertilizers have the capacity to burn if applied incorrectly. We’ve also been experimenting with compost tea. Swarthmore College, after upgrading their equipment, donated a 100 gallon tea brewer. The benefits of compost tea are many. As long as the organic matter in your soil is around 4%, soil biology can be supplemented with compost tea. When brewed correctly, it contains many beneficial organisms essential in the soil food web. Compost tea has been shown to suppress disease and extend root systems which in turn reduces the need for supplemental irrigation. It also improves plant growth by improving nutrient retention in the soil.
While Haverford may never be 100% organic, it’s important to explore all avenues when it comes to turf care.
Thanks to the NOFA Organic Lawn and Turf Handbook