Golf Course Environmental Profile Measures Nutrient Use and Management and Fertilizer Restrictions, Storage, and Equipment Calibration

Clark S. Throssell, Greg T. Lyman, Mark E. Johnson, and Greg A. Stacey, Golf Course Superintendents Association of America, 1421 Research Park Drive, Lawrence, KS 66049; and Clark D. Brown, National Golf Foundation, 1150 S. US Highway 1, Suite 401, Jupiter, FL 33477

Corresponding author: Clark S. Throssell. cthrossell@gcsaa.org

Abstract

The golf industry lacks comprehensive national data on the property features, management practices, and inputs associated with golf courses. To develop a national golf course environmental profile, a survey was sent to 16,386 superintendents at US golf facilities to determine their nutrient use, trends in nutrient use, nitrogen sources used, soil amendment and turfgrass supplement use, and fertilizer restrictions, storage, and equipment calibration. Of these surveys, 15.6% were returned. Analysis of data indicated a representative sample of golf facilities in the US was received with the exception of facility type. Data were weighted for facility type. Summed over all golf course components and all golf facilities, a total of 101,096 tons nitrogen were applied to 1,311,000 acres; 36,810 tons phosphate were applied to 1,131,000 acres; and 99,005 tons potash were applied to 1,260,000 acres in 2006. Only 9% of 18-hole golf facilities reported restrictions on fertilizer use required by a government or tribal authority, and 18-hole facilities calibrated their fertilizer application equipment before application 67% of the time. These results provide an accurate portrayal of golf course nutrient use and establishes a baseline for comparison with results from future surveys to monitor industry change over time.

Introduction

Golf course superintendents, golf industry leaders, golf association leaders, environmental advocates, university turfgrass scientists and state and local environmental regulators participated in meetings held in 2003 and hosted by The Environmental Institute for Golf (The Institute) (Lawrence, KS) to identify and prioritize research, education and outreach needs to help The Institute fulfill its mission of strengthening the compatibility of the game of golf with the natural environment. As an outcome of these meetings, it was learned that the golf industry did not have comprehensive data on property features, management practices and inputs associated with golf courses and their maintenance. An additional outcome was that, although many individual golf courses had made changes to become more compatible with the environment, no systematic process existed to document changes that the golf industry as a whole has made to protect and enhance the environment.

In recent years, state surveys of golf course maintenance practices have provided useful information. Unfortunately, survey questions were not uniform, and responses covered different time periods so that combining data from different state surveys would not produce a valid national profile of golf courses and their maintenance practices.

The Golf Course Superintendents Association of America (GCSAA) (Lawrence, KS) initiated a project in 2006 to collect data nationwide on property features, management practices, and inputs associated with golf courses and golf course maintenance. Five surveys conducted from 2006 to 2009 were used to collect the needed information. Once the first phase of data collection has been completed, the surveys will be repeated. This will provide data to determine change in golf courses and golf course maintenance practices over time.

Results from the first two surveys indicated that an average 18-hole golf course is 150 acres, of which 100 acres are maintained turfgrass; US golf courses irrigate an estimated 1,198,381 acres of turfgrass; and their total annual water use averaged over 2003, 2004, and 2005 is estimated at 2,312,701 acre-feet (4,10).

This survey was conducted in 2007, using 2006 data. The objectives of this survey were to determine: nutrient use; trends in nutrient use; nitrogen sources used; soil amendment and turfgrass supplement use; and fertilizer restrictions, storage, and equipment calibration on golf facilities in the US and its agronomic regions.

Question Development

Survey questions were developed following the same process used for the first two surveys (4,10). Input on survey questions was collected from golf, environmental, academic, and regulatory sources. GCSAA staff drafted questions which were reviewed and revised by golf course superintendents, golf association leaders, and environmental advocates. The National Golf Foundation (Jupiter, FL) conducted the survey and analyzed the data. The NGF adheres to The Code of Marketing Research Standards developed by the Marketing Research Association (5).

Survey Procedures

The same survey procedures were used for this survey as were used in the previous two surveys (4,10). An attempt was made to recruit 16,386 superintendents at golf facilities in the US to complete the nutrient use survey. Surveys were sent beginning 19 March 2007 by e-mail or mail and accepted until May 9, 2007. Several reminders to complete and submit the survey were sent by e-mail and mail. The survey is in Appendix A.

A total of 2,561 completed surveys were returned from 16,386 superintendents, yielding a 15.6% return rate. The data collected were not independently validated because of time and resource limitations. Completed surveys were screened to determine whether responses were reasonable in the context of the rest of the responses on that survey following the procedures used in the first two surveys (4,10).

Analysis of the completed surveys indicated a representative sample of the golf facilities in the US was received with the exception of facility type. Responses from private facilities accounted for 40% of the returned surveys but make up 29% of golf facilities (Table 1). Therefore, proportions of the collected sample were weighted to resemble the known golf facility demographics. Weighted data are presented in this paper. Agronomic regions and the location of golf facilities responding to the survey are shown in Figure 1. Agronomic regions were delineated by grouping geographic areas with similar agronomic and climatic characteristics using previously published regions as a guide (3,9). Boundaries were drawn using county borders.

Fig. 1. Agronomic regions of the US and location of survey responses received. Red dots indicate one or more responses were received from that zip code.

Data were analyzed using Quantum crosstabs and SPSS analytics software (SPSS 15.0 for Windows, SPSS Inc., Chicago, IL) to run descriptive statistics, and t-tests were performed to explore relationships between categorical variables such as agronomic region, course type, and number of holes. Confidence intervals of 90% were used for mean separation.

Where 18-hole equivalent data are presented, data within a region were averaged over facility type and budget. The number of 18-hole equivalents in the US is 14,969 and was determined by taking the total number of golf holes and dividing by 18 (7). All budgets and expenditures are reported in 2006 US dollars.

Nitrogen, Phosphate and Potash Use

Annual nitrogen, phosphate, and potash application rate by facility type. In general, the annual rate of nutrients [nitrogen, phosphate (P₂O₅), and potash (K₂O)] applied to individual components of golf courses was significantly higher on golf facilities with 27 or more holes, and 18-hole golf facilities applied significantly higher rates of nutrients than 9-hole golf facilities; private 18-hole golf facilities applied significantly higher rates of nutrients than 18-hole public golf facilities; and 18-hole golf facilities with an annual maintenance budget of > $1,000,000 applied significantly higher rates of nutrients than 18-hole golf facilities with a maintenance budget of $500,000 to $999,999, which applied a significantly higher rate of nutrients than 18-hole golf facilities with an annual maintenance budget of < $500,000 (data not shown).

Annual nitrogen, phosphate, and potash application rate by golf course component. On 18-hole golf facilities, greens, tees, fairways, practice areas, and turf nurseries are fertilized with a higher annual rate of nitrogen, phosphate and potash than rough, no-mow/natural areas and grounds (Table 2). Higher annual rates of nitrogen, phosphate and potash are applied to the components of the golf course that require the highest turf quality and are the highest priority for play, and in the case of turf nurseries, reflect the nutrient rate needed to produce high-quality turfgrass to replace damaged turfgrass on a green, tee or fairway.

Annual nitrogen, phosphate, and potash application rate by agronomic region. The annual nitrogen, phosphate, and potash application rate to each component of the golf course varied significantly by agronomic region (Table 2). For nitrogen, the annual application rate is primarily based on the turfgrass species grown, the length of the growing season, and whether the golf facility practices winter overseeding. For phosphate and potash, the annual application rate is based on soil test results with interpretation focused on soil texture and the annual nitrogen rate (2,6).

In the Southeast and Southwest agronomic regions where bermudagrass is a widely used species (4), nitrogen rates are higher for all components of the golf course than in other agronomic regions because bermudagrass requires a higher annual rate of nitrogen than other turfgrass species grown on golf courses (2,6). Higher annual nitrogen rates are used in the Southeast, Southwest, Transition, and Pacific regions due to a longer growing season.

Acres of winter-overseeded turf is greatest in the Southeast, followed by the Southwest and Transition agronomic regions (4). Winter overseeding contributes to the highest annual nitrogen application rate in the Southeast and Southwest agronomic regions (Table 2). Annual nitrogen rates reported by golf course component and agronomic region in Table 2 align with standard agronomic practice (2,6).

Since annual phosphate and potash application rates are partially based on the annual nitrogen application rate, annual phosphate and potash application rates follow the same trends for the same reasons as described above for agronomic regions (Table 2). The annual phosphate application rate was approximately 39 to 45% of the annual nitrogen application rate for all components of the golf course except for no-mow/natural areas where the annual phosphate application rate was 59% of the annual nitrogen application rate. The annual potash application rate was 97 to 106% of the annual nitrogen application rate for tees, fairways, rough, practice areas, no-mow/native areas, and grounds and was 129 to 135% of the annual nitrogen application rate for greens and turf nurseries.

Total annual amount of nitrogen, phosphate, and potash applied to all golf facilities. The total annual amount of nitrogen, phosphate, and potash applied to each component of a golf course is determined by multiplying the annual application rate by the number of acres fertilized. The total annual amount of nitrogen, phosphate and potash applied, summed over all golf facilities, was greatest on rough and fairways (Table 3). While fertilized at a lower rate, rough and fairways comprise the most acreage of a golf course (4). On the other end of the spectrum, greens and tees were fertilized at a higher annual rate than either rough or fairways but comprise substantially less acres of a golf course than rough or fairways.

The total pounds of nitrogen, phosphate, and potash applied to all golf facilities in 2006 and the acreage fertilized was 202,191,000 lbs nitrogen and 1,311,000 acres fertilized; 73,619,000 lbs phosphate and 1,131,000 acres fertilized; and 198,009,000 lbs potash and 1,260,000 acres fertilized (Table 3).

Total annual amount of nitrogen, phosphate, and potash applied by agronomic region. The total annual amount of nitrogen, phosphate, and potash applied to all golf facilities varied by agronomic region because of differences in the annual nutrient application rate and the number of acres fertilized. Golf facilities in the Southeast agronomic region applied a greater total annual amount of nutrients than golf facilities in any other agronomic region because the Southeast has the highest annual nutrient application rate and the greatest number of acres fertilized (Table 3). The total annual amount of nitrogen, phosphate and potash applied to golf facilities, expressed as a percent of the total applied in the Southeast agronomic region was North Central (47%, 40%, 33%), Southwest (46%, 55%, 37%), Transition (46%, 61%, 38%), Northeast (29%, 32%, 22%), Upper West/Mountain (19%, 21%, 14%), and Pacific (10%, 12%, 8%), for nitrogen, phosphate, and potash, respectively.

Time of Year of Nitrogen Applications

Nationally, 87% of the yearly total amount of nitrogen used is applied between March and October on an average 18-hole golf facility, with more nitrogen applied in May-June and September-October than in March-April and July-August (Table 4). These data reflect the active growing season of both cool- and warm-season grasses when nitrogen fertilization is required by the turfgrass for optimal performance. The seasonal application of nitrogen differed by agronomic region because of differences in the length of each region’s growing season. In January-February, significantly more of the yearly nitrogen was applied in the Southwest (11%) and in the Southeast (9%) than in the other regions to fertilize overseeded cool-season turfgrass which is found mainly in these regions (4).

Trends in Nutrient Use

For all agronomic regions, depending on golf course component, 50% to 70% of average 18-hole golf facilities, with two exceptions, fertilized with the same annual amount of nitrogen, phosphate, and potash in 2006 as in 2002 (Table 5). The percentage of 18-hole golf facilities that increased or decreased the annual amount of nitrogen applied was approximately the same for greens, fairways, and rough. On tees, practice areas, turfgrass nurseries, and grounds, more facilities increased the annual amount of nitrogen applied whereas in no-mow/native areas, more facilities decreased the annual amount of nitrogen applied. The percentage of 18-hole golf facilities that increased or decreased the annual amount of phosphate applied was approximately the same for tees, practice areas, turfgrass nurseries, and grounds. More facilities decreased the annual amount of phosphate applied to greens, fairways, rough, and no-mow/native areas. More facilities increased the annual rate of potash applied on greens, tees, fairways, practice areas, turf nurseries, and grounds, and more facilities decreased the annual amount of potash applied on no-mow/native areas. Only on rough was the percentage of 18-hole golf facilities that increased or decreased the annual amount of potash applied approximately the same (Table 5).

Several regional trends in nutrient use were noteworthy. In the North Central agronomic region, the annual amount of phosphate applied in 2006 was less than in 2002 for all components of the golf course. This result is possibly due to legislation enacted in Minnesota and Wisconsin that requires golf course superintendents to attend classes on phosphorus fertilization and the increased awareness of the unintended negative consequences of phosphate reaching surface waters (8). Also, the amount of phosphate applied annually decreased on tees in the Southeast, on fairways in the Transition, Southeast, and Southwest and on rough in the Transition, Southeast, Southwest, and Upper West/Mountain agronomic regions (data not shown). The annual rate of potash applied increased for all components of the golf course, except no-mow/native areas, in nearly all agronomic regions (data not shown).

Nitrogen Sources

Slow-release and-quick release nitrogen use. Slow-release nitrogen sources account for 64% and quick-release nitrogen sources for the remaining 36% of nitrogen applied to 18-hole golf facilities in the US (Table 6). Eighteen-hole golf facilities with a maintenance budget of less than $500,000 apply a significantly higher percentage of nitrogen from slow-release sources (66%) than golf facilities with a maintenance budget of $500,000 to $999,999 (64%), which apply a significantly higher percentage of slow- release nitrogen than golf facilities with a maintenance budget greater than $1,000,000 (58%). The percentage of nitrogen applied from slow-release sources is significantly higher in the North Central (69%) and Northeast (67%) agronomic regions but significantly lower in the Southwest (47%) (Table 6).

Organic nutrient use. For the purposes of this survey, an organic nutrient source was defined as "materials derived from either plant or animal products containing one or more elements (other than carbon, hydrogen, or oxygen) which are essential for plant growth" (1). Organic nutrient sources were applied to 66% of 18-hole golf facilities in 2006. Golf facilities with 27+ holes (73%) were significantly more likely to apply nutrients from organic sources than 18-hole (66%) and 9-hole (58%) golf facilities. Private golf facilities (69%) were significantly more likely to apply nutrients from organic sources than public golf facilities (65%), and golf facilities with a maintenance budget greater than $1,000,000 (72%) and from $500,000 to $999,999 (70%) were significantly more likely to apply nutrients from organic sources than golf facilities with a maintenance budget below $500,000 (60%). Nutrients from organic sources were most likely to be applied to 18-hole golf facilities in the Northeast (75%) and Southeast (71%) and least likely to be applied to those in the North Central (60%) agronomic region.

Among 18-hole golf facilities, the percentage of total nutrients from organic sources was greatest in the Northeast agronomic region (30%) and lowest in the Southeast (17%) (Table 6). Although 18-hole golf facilities in the Southeast were most likely to apply nutrients from an organic source, they applied the lowest percentage of total nutrients from organic sources.

In the US, 18-hole golf facilities showed a net increase of 35% in the amount of nutrients applied from organic nutrient sources from 2002 to 2006. The largest net increases were in the Southwest (58%) and Pacific (47%) regions and the smallest net increase was in the North Central (29%) agronomic region (Table 6).

Nutrients from organic sources applied on 18-hole golf facilities come from a wide range of sources. In 2006 the most-used organic nutrient sources were animal waste (59%) and commercial sewage products (40%) (Table 7).

Soil Amendments

For this survey, the soil amendments considered were gypsum, limestone, sulfur, calcium chloride, other, and none. For 18-hole golf facilities, 43% did not apply any soil amendments and 11% specified "other" amendment applied in 2006. The percentage of 18-hole golf facilities that applied a particular amendment and the average total amount applied to turfgrass at the golf facility were: 40%, 13.8 tons gypsum; 24%, 21.8 tons limestone; 9%, 5.4 tons sulfur; and 6%, 5.1 tons calcium chloride. Soil amendment use was most common on private 18-hole golf facilities with a maintenance budget greater than $1,000,000, and 18-hole golf facilities with a maintenance budget of $500,000 to $999,999 were more likely to apply soil amendments than facilities with a maintenance budget below $500,000 (Table 8).

Turfgrass Supplements

Turfgrass supplements include a range of products applied with the goal of improving turfgrass performance. Fertilizers, and soil amendments as defined above, are not included in the turfgrass supplements category. In 2006, 74% of golf course superintendents applied one or more categories of turfgrass supplements at 18-hole golf facilities in the US. The most common categories of turfgrass supplements applied were biostimulants (50%), humates (49%), and amino acids/proteins (46%) (Table 9). Private 18-hole golf facilities with a maintenance budget greater than $1,000,000 were the most likely to use turfgrass supplements. The specific turfgrass supplement applied varied by agronomic region, with golf course superintendents in the North Central (40%) region the least likely to apply turfgrass supplements (Table 9).

Nutrient Management Plans

Written nutrient management plans or written fertilizer programs were used at 49% of 18-hole golf facilities in the US (Table 10). The use of these written plans or programs was most common at golf facilities with 27+ holes (60%), which is significantly higher than at 18-hole (49%) facilities, which, in turn, is significantly higher than at 9-hole (40%) facilities. Use of these written plans or programs is nearly equal at public (50%) and private (49%) golf facilities. Golf facilities with an annual maintenance budget greater than $1,000,000 (50%) were significantly more likely to have a written nutrient management plan or fertilizer program than golf facilities with maintenance budgets of $999,999 to $500,000 (49%) and less than $500,000 (47%). Use of these plans did not differ significantly among agronomic regions (Table 10).

Only 6% of 18-hole golf facilities were required by a federal, state, local, or tribal authority to have a written nutrient plan (Table 10). Golf facilities that were required to have written nutrient management plans did not differ by number of holes, public or private, or maintenance budget. Eighteen-hole golf facilities in the Upper West/Mountain (11%), Transition (9%), Northeast (8%), and Pacific (8%) agronomic regions were most likely to be required to have a written nutrient management plan.

Seventeen percent of 18-hole golf facilities had a written nutrient management plan because they voluntarily participated with a non-regulatory organization such as a watershed protection or environmental conservation group (Table 10), but there was no relation between the number of holes and a golf facility’s participation with a group. Participation rates were significantly higher for public (18%) than private (14%) facilities and higher for facilities with higher maintenance budgets (20% of facilities with $500,000 to $999,999 budgets and 19% of facilities with budgets greater than $1,000,000 compared to 13% for facilities with budgets below $500,000). The participation rate of 18-hole golf facilities in the Pacific (31%) region was significantly higher than all other agronomic regions (Table 10).

Fertilizer Restrictions

Only 9% of 18-hole golf facilities reported restrictions on fertilizer applications required by a federal, state, local or tribal authority (Table 10). These restrictions were most likely in the North Central (16%) and Pacific (10%) agronomic regions (Table 10). Minnesota and Wisconsin have enacted legislation that requires education for superintendents on phosphorus use, which may account for the higher response rate in the North Central region.

The most common fertilizer restrictions encountered by 18-hole golf facilities are: phosphorus, yearly total and/or amount per application (62%); required use of buffer strips (33%); nitrogen, yearly total and/or amount per application (27%); no-fertilizer application zones (23%); potassium, yearly total and/or amount per application (9%); date restrictions on applications (5%); other nutrients (2%); and other (10%). Respondents reported the effects of the fertilizer restrictions on their nutrient application program as none (16%), minimal (50%), some (26%), and significant effect (8%). No attempt was made to determine the specific effect.

Nutrient Application Decisions

Golf facilities use many unique factors to guide nutrient application decisions, and a single golf facility will use multiple factors when making these decisions. The most common factors used to make nutrient application decisions and the percent of 18-hole golf facilities that are using them are: visual observations of turfgrass (85%), previous product performance (84%), soils/soil analysis (84%), precipitation/ temperature/ weather (83%), turfgrass species (81%), and disease pressure (79%) (Table 11). In general, golf facilities with 18 or 27+ holes and 18-hole golf facilities with maintenance budgets greater than $500,000 used the factors listed in Table 11 more frequently than either 9-hole golf facilities or 18-hole golf facilities with a maintenance budget below $500,000. Private and public golf facilities used the listed factors with the same frequency.

The importance of the factors used in making decisions about nutrient application differed by agronomic region reflecting the vast differences in soil, climate and water quality and quantity among agronomic regions (Table 11).

Soil Testing

Since 2002, 95% of 18-hole golf facilities have performed soil testing on greens, 75% on tees, 80% on fairways, and 26% on rough (Table 12). With the exception of soil testing on greens, facilities with 27+ holes were significantly more likely to soil test than 18- and 9-hole golf facilities. Private golf facilities were significantly more likely than public facilities to test the soil on all components of the golf course. The maintenance budget of an 18-hole facility had a significant effect on whether soil tests were performed on components other than greens, tees, and fairways, with significantly more of these tests done by facilities with a maintenance budget greater than $1,000,000 than by facilities with a budget of $500,000 to $999,999, and facilities in both these categories soil test all components of the golf course significantly more than 18-hole golf facilities with a maintenance budget below $500,000. Soil testing is performed least often in the North Central region (Table 12), possibly because of the productive soils that occur naturally throughout much of this area.

Fertilizer Storage

Of 18-hole golf facilities, 91% stored fertilizer on site for three consecutive calendar days or more in 2006. Of this 91%, 50% stored the fertilizer in a facility designed for fertilizer storage (at a minimum had an impervious floor, ventilation, containment features, locks, and restricted access). Of 18-hole golf facilities with a facility designed for fertilizer storage, private (55%) facilities significantly outnumbered public (48%) golf facilities, and golf facilities with a maintenance budget greater than $1,000,000 (63%) significantly outnumbered golf facilities with a maintenance budget of $500,000 to $999,999 (54%), which, in turn significantly outnumbered facilities with budgets below $500,000 (41%). Eighteen-hole golf facilities with a facility designed for fertilizer storage are most common in the Southeast (59%) and Pacific (58%) regions; and 44% to 51% of 18-hole golf facilities in the other agronomic regions have facilities designed for fertilizer storage.

Fertilizer Equipment Calibration

Eighteen-hole golf facilities calibrated their fertilizer application equipment before application 67% of the time. The average number of fertilizer applications in 2006 and the percent of times the fertilizer application equipment was calibrated before application were: greens, 17.7 applications with 65% calibration; tees, 7.3 applications with 63% calibration; fairways, 5.3 applications with 68% calibration; and rough, 3.9 applications with 69% calibration.

These data indicate golf facilities are calibrating fertilizer application equipment frequently, increasing the likelihood that the desired amount of nutrients is being applied.

Conclusions

Application of nitrogen, phosphate, and potash is essential for the production of all agricultural crops, including turfgrass on golf courses. Summed over all golf course components and all golf facilities, a total of 101,096 tons nitrogen were applied to 1,311,000 acres or 154 lbs nitrogen per acre; 36,810 tons phosphate were applied to 1,131,000 acres or 65 lbs phosphate per acre; and 99,005 tons potash were applied to 1,260,000 acres or 157 lbs potash per acre (Table 3). By contrast, in 2005, corn was grown on an estimated 76,122,000 acres in the US and was fertilized with 4,690,000 tons nitrogen, 1,696,000 tons phosphate, and 1,901,000 tons potash. Not all acres of corn were fertilized with nitrogen, phosphate, or potash, and the pounds applied per acre were: 138 lbs nitrogen; 58 lbs phosphate; and 84 lbs potash (11). The rate of fertilizer applied per acre to turfgrass on golf courses compared to corn was 112% for nitrogen and phosphate; and 187% for potash. The total amount of fertilizer applied to turfgrass on golf courses in 2006 was 0.8% of the nitrogen and phosphate and 2.1% of the potash applied to corn in 2005.

In 2006, fresh tomatoes were grown on 105,600 acres in program states reporting data and were fertilized with 11,396 tons nitrogen, 6,529 tons phosphate, and 14,933 tons potash. Not all acres of tomatoes were fertilized with nitrogen, phosphate, or potash and the pounds applied per acre were: 216 lbs nitrogen; 132 lbs phosphate; and 286 lbs potash (11). The rate of fertilizer applied per acre to turfgrass on golf courses was 71%, 49%, and 55% of the rate of nitrogen, phosphate and potash applied to tomatoes, respectively. The examples of fertilizer use cited demonstrate that turfgrass on golf courses is fertilized in-line with other crops.

Quick-release and slow-release nitrogen sources and inorganic and organic nutrient sources are applied to most golf courses throughout the US. Golf course superintendents decide the rate applied, the frequency of application, the time of year applications are made, and the product used and thereby determine whether the fertilizer applied has the desired affect on the turfgrass without negatively affecting the environment.

By considering multiple factors when making nutrient application decisions, superintendents are integrating many variables into their decisions that lead to effective applications for the turfgrass while protecting the environment. A written nutrient management plan or a written fertilizer program provide the means to achieve goals and should be used by 100% of golf facilities.

Since 2002, only 26% of 18-hole golf facilities had soil tests conducted on the rough. On an average 18-hole golf facility, the rough comprises 50 acres (4), more than any other component of a golf course, and since the greatest total amount of phosphate and potash are applied to rough (Table 3), superintendents should test soil in the rough routinely to curtail costs and develop fertilizer programs that meet, not exceed, the nutritional needs of turfgrass.

In 2006, of the 18-hole golf facilities that stored fertilizer for more than three consecutive days, 50% did so in a facility designed for that use. The golf industry should increase the number of golf facilities that have a facility designed for fertilizer storage. Superintendents regularly calibrate fertilizer equipment to ensure that fertilizer is applied at the desired rate.

These results provide an accurate portrayal of golf course nutrient use to guide industry agronomic and environmental initiatives and establish a baseline that can be compared to results from future surveys to monitor industry change.

Acknowledgments

The authors thank The Toro Giving Program for providing a grant to help fund this research.

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Appendix A: The Survey

Golf Course Environmental Profile: Nutrient Use Survey (PDF).