Technical Bulletin

Apply Organic MATTER- Reduce nutrient requirement

In 1997 and 1998 a study at the Ohio Turfgrass Foundation Research & Education Facility found that half as much nitrogen fertilizer was needed on bentgrass fairways receiving treatments of organic biosolids.(1)

• "In both years of the study, the composted biosolids treatment increased the concentration of foliar nitrogen by 50% above that measured in the control which received no topdressing."
• "Treatments receiving the medium fertility rate plus composted biosolids had a higher percentage of foliar nitrogen than that observed in the high fertility treatment without topdressing…(and) similar between the results of low and medium fertility treatments."
• "The composts used in this work clearly enhanced turfgrass color and increased growth and foliar nitrogen concentrations."
• "Concentrations of foliar nitrogen concentrations were significantly increased on plots treated with compost for 55 days after the May application and for 26 days after the September application."
• "Accounting for these types of interactions between compost topdressing and fertilizer applications becomes especially critical because of the relationship between turfgrass fertility and disease susceptibility."

Conclusion: "The observed fertility effects resulting from the application of composted biosolids are significant and need to be considered in the design of fertility programs that include inorganic nitrogen fertilizer applications."

1. Boehm, M.J., J.W. Rimelspach, D.C. Garling. 2001. Organic materials boost fairways. Golf Course Management Vol. 69, No.2, February 2001: 61-64.