Legacy Ridge Golf Course transitions to organic compost products

The golf course maintains proper nutrient management as part of its agronomic BMPs

Chris Johnson, superintendent
Legacy Ridge Golf Course, Westminster, Colo.
Publication date: May 2011

Legacy Ridge Golf CourseLegacy Ridge Golf Course (LRGC) and The Heritage at Westmoor Golf Course are both owned and operated by the city of Westminster, Colo. Both are located along the Front Range of Colorado’s Rocky Mountains. 

The city’s 18-holes are well maintained and highly conditioned to offer challenges to players of all levels and abilities. Maintaining proper nutrient management is an important aspect of our agronomic best management practices as it helps to ensure healthy turfgrass and a quality playing experience.

Managing nutrients

Since Legacy Ridge opened in 1994, our nutrient management program has undergone significant changes. Basic fertility schemes are used in accordance with university and manufacturer recommendations. In 2000, we started irrigating with reclaimed water that contained high levels of nutrients. Nutrient rates and applications were adjusted. Today, nutrient levels in reclaimed water are reduced and have incorporated the use of organic compost.

Synthetic fertilizers

Traditionally, Legacy Ridge used synthetic fertilizers primarily with different types of organic fertilizers. We slowly transitioned to using organic fertilizer and compost with small steps. In the fall of 2008, we tested two different synthetic fertilizers and a bio-compost. The trial tested dormant winter fertilizer application on fairways. The compost was light and dry, and contained two particle sizes: dust and wood mulch. The green up on the composted fairways was significantly faster in the spring. Wood chips disappeared soon after mowing began. In the spring of 2009, staff members attended a vendor’s seminar that focused on soil testing, microbe feeding, and building better soils by using organic fertilizer products. We continued with compost applications on our fairways and incorporated some of the information learned at the seminar.

Making informed decisions

Legacy Ridge Golf CourseBasic guidelines established what kind of compost to look for. The U.S. Composting Council, an online compost resource, offers a Seal of Testing Assurance Program. It details compost testing, labeling, and information disclosure. The program also provides information about participating manufacturers’ products. This teaches courses how to research and purchase nutrient management products. We also found information defining the classification system for composts as well as the use of the Ag Index test result, which is the ratio of nutrients to sodium and chloride. This information was vital to meeting our nutrient requirements. Implementing these requirements ensured that the course stayed on the right track to achieving healthy turfgrass and performance, environmental protection, and improved efficiency. Two criteria were discussed:

  1. Salt water levels were a concern. We did not want to use any product that would coincide negatively with our reclaimed water.
  2. Mature compost that could spread evenly would also be used.

Classifying compost

The Rocky Mountain Organics Council’s compost classification system helps courses understand compost types, origin, and uses. Class I composts are derived mostly from yard waste. They typically have lower nutrient value and salt load. Class II products are manure-based and higher in nutrients and salts. Class I and Class II composts were our best option. Price is always a concern, but we were looking for good value, not a cheaper product. Class I composts are typically more expensive than Class II. We reviewed numerous composts from many local suppliers. Using our guidelines and pricing, we narrowed the field down to three possibilities.  

Sample testing

Legacy Ridge Golf CourseSamples taken from our course were sent to a local certified lab and tested. Our test matrix was upgraded to include sodium so the Ag Index could be calculated. The Ag Index was used to compare products. The Ag Index indicates sodium build-up potential in the soil versus the nutrient build-up. It details which compost helps and/or hurts a course’s soil. Monitoring sodium levels and tracking soil and water test results is important to our agronomic programs. One of the three samples tested stood out as a clear frontrunner. The sample’s salts were low, the Ag Index was high, and it had good nutrient amounts. Values of 10 or better on the Ag Index indicate good nutrient amounts without a toxic build up of sodium and chlorides. We selected a mature, stable, product with a spreadable consistency. The low cost product is sold as a Class II compost, and is a mixture of 30% Class I and 70% Class II.

Applications

Legacy Ridge Golf CourseThe compost application rate was 5 cubic yards per acre. This gave us around 1 pound of nitrogen, 0.5 pounds of phosphorous, and 1 pound of potassium per 1,000 square feet. By using compost rather than synthetic fertilizer, we get high amounts of micronutrients that feed microbes to help build healthy, sustainable soil. Our compost order for the spring of 2010 was 120 cubic yards. We expanded to 160 cubic yards in the fall, and to 200 cubic yards for the spring 2011 application. Applications were made with two large area topdressers to approximately 22 acres of fairway. The same application process was repeated in the fall of 2010. We and our supplier were not satisfied with the high amount of debris left behind in the application process. During the winter of 2010-2011, our supplier invested in a new screening system that eliminated almost all foreign material from the compost. One drag with a keystone mat was all that was needed to work the compost into the turf canopy. In 2011, we added another 6 acres of turf to the composting program by covering tees, approaches, and fairways. We used the same supplier. Our cost increased with the new screening system. The analysis was a little different than the previous year, but still within our guidelines. Compost test results varied. Key parameters were graphed and/or charted for visual comparison.

Test results

Legacy Ridge Golf CourseThe results of our hard work were visible on the greens. The compost applications on our fairways, tees, and approaches have all been visual, especially in early spring. The composted areas are significantly greener. They wake up from winter dormancy earlier than other areas. There has not been an increase in drought areas, fairy ring or other diseases. The turf density and color are both good.

Fertilization

Our fairways have never been fertilized with this balanced of a fertilizer. In recent years, our fairways have received nothing more than nitrogen, iron, and growth regulators. It would be difficult to compare the cost of compost versus a comparable synthetic fertilizer because of the amount of micronutrients in the compost. An N:P:K ratio fertilizer (similar to our compost) with 3% iron and micronutrient might cost 20% more for a single application. The compost is also a relatively slow release product. This potentially drives up the cost of synthetic fertilizers.

The future

We plan to continue the current compost program and slowly expand it into the rough areas as the budget allows. High traffic and worn rough areas already receive leftovers from other applications. Our goal is to ensure that the compost fits our quality guidelines. We will also adjust our guidelines as needed. Our soil sampling program currently covers four fairways per year. This program will provide us with an indication as to whether or not changes in the program need to be made. Soil and water sampling have been standard practices on both courses since the construction phases. Our record keepers will notify us if there is an increase in disease pressure, thatch levels, or any other pattern. The transition of organic compost into our nutrient management program has had positive benefits for healthy turfgrass and performance. While financial benefits have not been quantified, they are a realized benefit. Investing time and staff resources into the project have helped us implement the use of compost in an efficient and effective manner. Learn more about the Legacy Ridge Golf Course.