Effect of topdressing of compost, compost tea, and various fertilizers on soil and lawn characteristics

Many cities in the United States collect and compost yard waste but need more effective and efficient ways to utilize the finished product. Home lawns represent a sizeable area that could benefit from land application of yard waste compost, but little research has been conducted regarding topdressing lawns with compost. The objectives of this study were to compare the impact of topdressing yard waste compost relative to organic and inorganic fertilizers in a mature, predominantly Kentucky bluegrass (Poa pratensis L.) lawn in Wisconsin. Three different composts (two from yard waste and one from food waste), two organic fertilizers, and a compost–compost tea combination were compared against a traditional synthetic fertilization program and a nontreated control. Treatments receiving compost (1.3 cm depth per year, in two equally sized applications) maintained acceptable turf quality over the 3.5-yr study period and resulted in significant improvements in several important physical properties of the soil. Fertilizers were also able to maintain acceptable turfgrass quality but had no impact on the physical properties of soil over the study period relative to the control. Organic and synthetic fertilizers reduced weed populations compared with the control, though the compost treatments did not. Compost and one of the organic fertilizers significantly increased the levels of soil test P but did not reach levels of environmental concern.