06 - NUTRIENT MANAGEMENT
Proper golf course nutrient management is central to maintaining healthy turfgrass, reducing environmental risk, and managing expenses. Proper nutrient selection, application method, fertilizer application rates, and scheduling allow turfgrass to recover from damage, increasing its resistance to stress, and improving playability. It is important to follow a thoughtful nutrient management plan to maximize turfgrass health and minimize potential risk to the environment. Proper management helps prevent leaching or runoff in order to protect surface and groundwater resources. The goal of a nutrient management program should be to apply minimal nutrients to achieve an acceptable playing surface in the most efficient manner, helping the plant to recover from the stresses that it faces. Examples of stresses include excessive wear, drought, disease, and insect pests.
The foundation of a nutrient management program incorporates three types of professional analysis in order to ensure turfgrass health, performance, and recovery: soil, plant tissue, and water sampling.
Regulatory Considerations
The Office of the Texas State Chemist (OTSC) governs fertilizer laws and rules regarding manufacturing, distribution, and labeling of commercial fertilizers within the state. Depending on the location, regulatory agencies may include local policies. In general, if the location is regulated by nutrient policies (such as required nutrient management plans), all nutrient BMPs will need to be designed according to these policies.
Additional information on Texas Agriculture Code, Chapter 63, Sec. 63.031, Texas Administrative Code, Title 4 Agriculture, Chapter 65, and OTSC laws and rules:
Soil Testing and Soil Health
Texas climate and parent materials produce extremely diverse soils. With 15 land resource areas across Texas and approximately 1,300 mapped soil series there is significant variation in soil health and requirements. Most Texas soils are classified into 7 major soil orders: Alfisols, Aridisols, Entisols, Inceptisols, Mollisols, Ultisols, and Vertisols. There are also small areas of two other orders (Histosols and Spodosols).
Although soils are acidic in the eastern part, most Texas soils have neutral or alkaline pH, and the majority of native soils have low phosphorous availability and high potassium (except those in the eastern portion of the state). Soil testing is an important step to aid with diagnosis, treatment, and maintenance of healthy turfgrass.
Soil in good health retains water, releases nutrients, and drains well. A well-balanced soil must contain adequate nutrients, optimum pH, and organic matter to produce high-quality playing surfaces and turfgrass health. The purpose of soil sampling is to provide a detailed report of variables such as the soil’s microbiology, composition, pH, organic matter content, salinity, and nutrients available for plant use. It also offers a prediction of how a plant will respond to applied nutrients. Proper use of testing results includes analysis, interpretation, and recommendations.
Determine management areas of the golf course and take 10 to 15 random soil core samples from each area. Each sample should be from the same depth, a six-inch depth (or four-inch for golf greens and tees). Break the cores and mix them together in a clean plastic bucket, removing debris. Determine a labeling system and place three cups of the mixed soil in a labeled bag for the soil testing lab.
Select a laboratory which uses a nutrient extraction method appropriate for the soils. The Mehlich-3 soil tests are common in Texas. Texas A&M University AgriLife Extension Service may be consulted to get the most current information and to better understand which soil test values are relevant for the location. The local conservation district and or USDA Natural Resources Conservation Service may also be able to provide technical assistance to help understand local soil processes and health:
https://www.nrcs.usda.gov/wps/portal/nrcs/surveylist/soils/survey/state/?stateId=TX
Soil Sampling / Testing in Texas
Soil tests can be used to estimate the kinds and amounts of soil nutrients available to plants. They also can be used as aids in determining fertilizer needs. Properly conducted soil sampling and testing can be cost-effective indicators of the types and amounts of fertilizer and limestone needed to improve crop yield.
Soil, Water and Forage Testing Laboratory
2478 TAMU College Station, Texas 77843-2478
Address for all other couriers (FedEx, UPS, etc.):
Soil, Water and Forage Testing Laboratory 2610 F&B Road College Station, Texas 77845 http://soiltesting.tamu.edu/
Stephen F. Austin University Soil Testing Lab Ag Building Room 122 Wilson Drive, P.O. Box 9020 Nacogdoches, TX 79562 (936) 568-4500 http://www.sfasu.edu/academics/colleges/forestry-agriculture/academics/agriculture/research-outreach/soil-plant-water-analysis-lab
A & L Ag laboratories 302 34th Street, P.O. Box 1590 Lubbock, TX 79408 (806) 763-2760
High Plains Laboratory, Inc 1502 W. Park, P.O. Box 791 Hereford, TX 79045 (806) 364-0242
Texas Plant and Soil Lab 4915 W. Monte Cristo Rd. Edinburg, TX 78541 (956) 383-0739 https://www.tpslab.com/soil-testingf0866a47
Thomas Turf Services 11183 State Highway 30 College Station, TX 77845 Attn: Bob Yzaguirr (979) 774-1600 http://thomasturf.com/
Best Management Practices
Accurate and consistent sampling is essential to providing useful soil test information over time.
Divide the course into logical components such as greens, fairways, tees, roughs, etc., for each hole.
Randomly collect 10 to 15 soil samples from each section, at the same depth (6” depth or 4” for golf greens and tees), and blend together to provide a representative, uniform soil sample.
The same extraction method must be used for each test in order to compare results over time.
If the location has correlation data between a given nutrient applied to soil and a response to that nutrient by turfgrass, then recommendations may provide expected results.
If the location does not have correlation data, then soil test recommendations may be of little value.
Maintain soil test records from prior years to allow observation of changes over time.
This practice can provide good evidence of the impact of the nutrient management plan.
Soil pH
Identifying pH levels may be the most important soil test results for turfgrass managers. The pH scale varies from 0 to a high of 14 with 7 considered being neutral. The pH value represents how much Hydrogen (H+) is present in the soil. Values below 7 contain more H+ and are considered more acidic and values above 7 have less H+ and are considered more alkaline. It is worth noting that pH is a logarithmic scale, meaning each change in one whole number signifies a tenfold increase/decrease in value. Therefore, a soil with a pH of 6 is ten times more acidic than a soil with a pH of 7. Typically, soil pH can vary from 4 to 10.
Nutrient Availability Relative to Soil pH
In most cases, a pH of 6-7 is ideal because it provides the greatest availability of all essential nutrients for turfgrass.
Source: R. Goldy, Michigan State University Extension
The soil pH is usually a function of precipitation which induces more leaching of Ca, Mg, and K ions which are replaced with H and Al ions. Other factors that affect soil pH are parent material of the soil, organic matter content, and fertilizing practices. Nitrogen applications generally have an acidifying affect because of the release of H ions.
Soil pH adjustments are difficult on established turfgrass. Often, large quantities of certain elements are needed to see significant changes in soil pH and therefore are best accomplished before turfgrass establishment. The pH of irrigation water can have a cumulative effect on soil pH since it is the input that is applied most often throughout the growing season.
In some cases, it may be necessary to correct for acidity or alkalinity. The Texas Almanac has a full list of the different soil types found in Texas: https://texasalmanac.com/topics/environment/soils-texas
When a soil test indicates an acidic soil, the following materials are most commonly used as amendments:
Calcitic limestone- CaCo3
Dolomitic limestone- CaMg (CO3)
Soil tests are the only way to determine if the turfgrass soil requires limestone. The rate required for liming materials is determined both by the starting pH and by the soil texture. Soils with more clay and silt require more limestone than sandier soils. Soils with higher organic matter content may also require more limestone than a soil with a lower organic matter content.
If a soil test shows a pH of above 8.0, it is considered alkaline and the pH should be lowered when possible. In this situation, an application of Sulfur (S) at the appropriate rate (depending on if it is pre-plant or post-plant) can help decrease pH to more favorable levels. Sulfur can be applied by using elemental Sulfur, Ammonium sulfate, iron sulfate, or potassium sulfate. Based on area soils, it may be easier to raise the pH than to successfully and consistently lower it. Consult a soil specialist in the case of high alkalinity to ensure a strategic plan is in place.
Best Management Practices
Maintain a pH in the range of 6.2 to 7.0 to optimize nutrient availability and reduce fertilizer requirements.
A liming material (calcium carbonate, calcium oxide, dolomitic limestone) that contains Ca and neutralizes acidity can be applied to increase soil pH.
Limestone moves slowly through the soil profile at a rate of .5 inch to 1 inch per year. It may take two or more years for limestone to increase the pH of the rootzone. Test soil every two years to determine pH and make corrective applications.
Products containing elemental sulfur (calcium sulfate, magnesium sulfate, potassium sulfate) should be applied when soil pH needs to be lowered.
Regular nitrogen fertilization will slowly reduce the soil pH over time.
In some cases, utilizing injection pumps into irrigation water to address pH can be beneficial.
Often, high pH soils (above 8) contain excess sodium (Na), in which case gypsum (CaSO4) would be useful to improve soil structure, nutrient availability, and plant health.
Plant Tissue Analysis
Nutrient management decisions should be guided with plant tissue analysis in conjunction with soil samples taken from the same areas. Plant nutrient content can be analyzed from clippings for nutrient concentration levels. These values are compared to a critical level range indicating deficiency, sufficiency, or excess. The following should be monitored: turfgrass quality, clipping yield, and performance. Analysis of these variables can be used to support nutrient management decisions. Low nutrient levels in tissue may indicate compromised root health/uptake that may be caused by other biotic and abiotic issues (nematodes, compaction, disease, etc.) Tests every three to six months is recommended on greens and every six to twelve months on tees and fairways.
Best Management Practices
Tissue samples may be collected during regular mowing.
Do not collect tissue after any event that may alter nutrient analysis.
Place tissue in paper bags. Do not use plastic.
If possible, allow tissue samples to air dry before mailing them.
Sample poor quality turfgrass that is of concern separately from higher quality turfgrass.
Collect a sample as soon as turfgrass begins to show signs of nutrient stress.
More frequent tissue sampling allows more accurate assessment of turfgrass nutrient status and how it changes over time.
The quantity of tissue analysis should be based on individual site needs. Two to four site tests per year are common on greens while 1 to 2 tests per year are common on fairways and tees.
Keep tissue tests from previous years for observation of changes over time.
Tissue testing can provide good evidence of the impact of nutrient management programs.
Plant Tissue Analysis Labs in Texas
Soil tests can be used to estimate the types and amounts of soil nutrients available to plants. They also can be used as aids in determining fertilizer needs. Properly conducted soil sampling and testing can be cost-effective indicators of the types and amounts of fertilizer and limestone needed to improve crop yield.
Texas A&M AgriLife Extension Service Diagnostic Testing Lab 1500 Research Parkway, Suite A130 College Station, TX 77845 (979) 845-8032
https://agrilifeextension.tamu.edu/ browse/diagnostic-labs-services/
http://soiltesting.tamu.edu/webpages/swftlmethods1209.html
TPS Lab 4915 W. Monte Cristo Rd. Edinburg, TX 78541 (956) 383-0739 https://www.tpslab.com/plant-testing
Water Sampling
The largest input to turfgrass is often water applied through irrigation. Impacts of water quality can have significant impacts on soil nutrients, soil structure, and nutrient availability. Water tests, along with soil sampling, will provide the greatest level of understanding to the proper ratios of applied nutrients required. Keep accurate records to show impact from the NMP. Managing a spreadsheet of sampling over time assists in understanding long-term impact on soil and plant health.
Reference Water Quality Monitoring and Management, Surface Water Management, and Irrigation (accounting for nutrients in reclaimed water) for additional BMPs.
Fertilizers Used in Golf Course Management
The components of fertilizers are important to understand in order to make informed decisions and appropriate applications. Carbon, oxygen, and hydrogen are among the 18 nutrients considered to be essential for the growth of plants. Natural processes within the plant allow for these three elements to be provided and they are generally not supplied as fertilizer.
The remaining 14 essential elements are further classified as either macronutrients or micronutrients.
Macronutrients:
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Calcium (Ca)
Magnesium (Mg)
Sulfur (S)
Micronutrients:
Iron (Fe)
Manganese (Mn)
Boron (B)
Copper (Cu)
Zinc (Zn)
Chlorine (Cl)
Nickel (Ni)
Molybdenum (Mo)
Cobalt (Co)
Each of these nutrients are essential and used in various amounts within the turfgrass plant. Those used in the greatest quantities are nitrogen (N), phosphorus (P), and potassium (K). These three nutrients are often found at levels insufficient for optimum growth and therefore, they are often the largest component of turfgrass fertility programs. Note that it is important to understand that “greater quantities” doesn’t necessarily mean “more important”. Justus von Liebig’s Law of the Minimum states that yield is proportional to the amount of the most limiting nutrient, whichever nutrient it may be – in other words, a nutrient management program is only as strong as its weakest link. Meaning if N, P, and K are all there – but iron isn’t, the turf will still suffer.
Best Management Practices
Understand the importance of application timing for effective use of applied nutrients.
The objective of all nutrient applications is to maximize plant uptake and the corresponding desirable response. Remember the 4R’s: right source, right rate, right time, right place; a general guide to help keep nutrients on and in the area of application.
Conduct soil testing to determine exact nutrient or other soil needs.
Apply soluble/quick-release nutrients when turfgrass is actively growing.
Apply slow-release nitrogen fertilizers at the appropriate time of year to maximize the products’ release characteristics. Nitrogen application rates from slow-release materials should take into consideration the release rate of the chosen material. If insufficient material is applied, the desired response may not be observed.
Consult Texas A&M University AgriLife Extension for efficient nutrient application levels in the location.
Excessive traffic damage on putting greens or tee boxes and compaction due to cart traffic on fairways can affect turfgrass health, which may result in an increased need for nutrition; monitor wear and provide nutrients as needed to promote recovery.
Fairways and roughs often require fewer nutrient inputs than other locations because of their increased height of cut, lower levels of damage, clipping return, and base of native soils.
Exercise caution when applying nutrient applications during turfgrass establishment as these applications are particularly susceptible to loss via leaching and runoff; consider “spoon-feeding” areas during establishment (lower rates, increased frequency) until a more robust root system is developed.
Apply appropriate rates and products to minimize N loss without reducing turfgrass establishment.
Increased water applications
Increased nutrients to hasten establishment
Reduced root mass
Be aware of the different types of spreaders and understand the advantages and disadvantages of each.
Not all fertilizers can be spread with every spreader. For example, if sulfur-coated urea was spread through a drop spreader, the sulfur coating could be damaged, essentially leading to an application of soluble urea. Be sure to consult the product label, many products will be explicit on the label regarding what kind of equipment should be used.
Choose the appropriate application equipment, correctly calibrated, for a given fertilizer material.
Walk-behind rotary
Drop spreader
Bulk rotary
Sprayer
Proper fertilizer storage, loading, and clean-up reduce environmental risk.
Avoid applying fertilizer to wet soils that are at, or near, field capacity or following rain events that leave the soils wet.
Do not apply fertilizer when the National Weather Service has issued a flood, storm watch or warning, or if heavy rains are likely.
Reference additional information:
https://soils.wisc.edu/facstaff/barak/soilscience326/lawofmin.htm
Nutrient Management Terminology
Developing an efficient nutrient management program requires a good understanding of the components of fertilizers, the fertilizer label, and the function of each element within the plant.
Grade or analysis is the percent by weight of Nitrogen (N), Phosphorous fertilizer (P2O5) and Potassium fertilizer (K2O) that is guaranteed to be in the fertilizer.
A complete fertilizer contains N, P2O5, and K2O.
The laws governing the labeling of fertilizer vary greatly among states. Consult https://otscweb.tamu.edu/Laws/FertLaws.aspx
Label
The label is intended to inform the user about the contents of the fertilizer which, if understood and followed, will result in little to no environmental risk. The fertilizer label may contain:
Brand
Grade
Manufacturer’s name and address
Guaranteed analysis
“Derived from” statement
Net weight
Macronutrients
Macronutrients are required in greater quantities and include Nitrogen (N), Phosphorous (P), and Potassium (K). Understanding the role of each of these macronutrients within the plant will provide a greater understanding of why these nutrients play such a key role in proper turfgrass management.
Simplified conceptual model illustrating the nitrogen cycle.
Environmental factors and management practices at the time of fertilizer application may influence nitrogen processes on the turfgrass and in the soil; these practices may cause nitrogen loss through multiple nitrogen pathways in the soil-plant-atmosphere system. Proper management of the source, rate, timing, and method of N application can help reduce N loss to prevent potential negative environmental effect due to leaching, denitrification, and volatilization.
Source: https://www.gcmonline.com/ course/environment/news/turfgrass-nitrous-oxide
Role of Nitrogen
Nitrogen (N) is typically required in greater quantities by turfgrasses than any other element except carbon (C), hydrogen (H), and oxygen (O). N plays an important role in numerous plant functions including being an essential component of amino acids, proteins, and nucleic acids.
The goal of all applied nutrients is to maximize plant uptake while minimizing nutrient losses. Understanding each process will increase ability to make sound management decisions and increase profitability while reducing environmental risk.
To aid in this, understand the fate and transformation of N along with the release mechanisms and factors affecting N release from various N sources.
Nitrogen Processes
Understanding how certain N sources should be blended and applied is an essential component in an efficient nutrient management plan. In many cases, N sources are applied without regard to how they are released. Each N source is unique and should be managed accordingly. Applying a polymer-coated urea (PCU) in the same manner as a sulfur-coated urea (SCU) greatly reduces the value of the PCU. Similarly, applying 2 pounds of N from ammonium sulfate may cause burning, while applying 2 pounds of N from certain PCUs may not provide the desired turfgrass response. Rate, release curve, application date, location, and turfgrass species should all be considered in the nutrient application decision.
Soluble nitrogen sources:
Urea (46-0-0)
Ammonium sulfate (21-0-0)
Diammonium phosphate (18-46-0)
Monoammonium phosphate (11-52-0)
Calcium nitrate (15.5-0-0)
Potassium nitrate (13-0-44)
Quick-release sources of N are often characterized by short bursts of growth followed by slow growth resulting in a peak and valley growth response by turfgrasses that may result in compromised root growth.
Slow-release nitrogen sources:
Sulfur-coated urea
Polymer/resin-coated
Isobutylidene diurea
Urea-formaldehyde reaction products
Natural organic
Slow-release fertilizers are any fertilizer where the release of the N into the soil is delayed either by requiring microbial degradation of the N source, by coating the N substrate which delays dissolution of N, or by reducing the water solubility of the N source. These products are dependent on microbial activity, so there can be some variability in their performance as a function of soil ecology, moisture, and temperature.
Some fertilizers combine both slow- and quick-release forms combining the advantages of both.
Urease and nitrification inhibitors:
Urease inhibitors reduce the activity of the urease enzyme resulting in a reduction of volatilization and increase in plant available N.
Nitrification inhibitors reduce the activity of Nitrosomonas bacteria, which are responsible for the conversion of NH4 to NO2. This reduced activity results in a reduction of N loss via denitrification and an increase in plant available N.
Role of Phosphorous
Phosphorus (P) is essential for plant growth and is involved in the transfer of energy within the plant. The role of phosphorous is important in seed germination, seedling vigor, and rooting responses. P is critical in turfgrass establishment and should be incorporated during establishment when soil tests indicate a deficiency.
P can be a growth limiting factor for many organisms and is a major contributor to eutrophication of water bodies. Proper timing and rates should be adhered to in order to reduce the risk of off-site movement. P loss often occurs with sedimentary runoff loss caused by sparse vegetation and exposed soil; take steps to mitigate soil loss and avoid application to bare soil.
P may remain in an organic form or may become incorporated into organic compounds and application rates should be based upon soil test results from documented correlations demonstrating a turfgrass response to soil test phosphorous levels.
Phosphorous deficiency symptoms:
Deficiency symptoms include slow growth and weak stunted plants.
Initially, reduced shoot growth and dark green color may be observed.
Subsequently, lower leaves may turn reddish at the tips and then the color may progress down the blades.
Phosphorous fertilizer sources:
Diammonium phosphate (18-46-0)
Concentrated superphosphate (0-46-0)
Monoammonium phosphate (11-52-0)
Natural organic
Role of Potassium
Potassium (K) is an essential element directly involved in maintaining the water status of the plant, turgor pressure of cells, and opening and closing of the stomata. K is of no environmental concern, but can be an economic concern, especially when K is over-utilized, which is quite common. As a general rule, concentrations of K are about 1/3 to ½ of N.
K is not a component of any organic compound and moves readily within the plant. K is a key driver of osmoregulation which has been documented to increase stress tolerance.
K deficiencies are generally a greater concern in sand-based root zones prone to leaching as K is highly soluble, monitor K levels more closely in greens and tee boxes.
POTASSIUM deficiency symptoms:
Except under severe, documented deficiencies, K may not have an observable influence on turfgrass appearance. Yellowing of older leaves followed by tip dieback and scorching of leaf margins have been reported.
Tissue concentrations of less than 1% are considered deficient.
Potassium sufficiency ranges:
Consult TAMU for sufficiency ranges for the specific location.
Potassium fertilizer sources:
Potassium sulfate (0-0-53)
Potassium chloride (0-0-62)
Potassium nitrate (13-0-45) Natural organics
Secondary Macronutrients
Secondary macronutrients are essential to plant function and are required in amounts less than N, P, and K but more than micronutrients. These include calcium (Ca), magnesium (Mg), and sulfur(S).
Role of Secondary Macronutrients
Micronutrients
Understanding the role of micronutrients within the plant should provide a greater understanding of why these nutrients play such a key role in proper turfgrass management.
Micronutrients are just as essential as macronutrients, but they are required in very small quantities compared to macronutrients. Micronutrients include iron (Fe), manganese (Mn), boron (B), copper (Cu), Zinc (Zn), molybdenum (Mo), and Chlorine (Cl).
Consult TAMU for sufficiency ranges of micronutrients in the specific location.
Role of Micronutrients
Biostimulants to Reduce Environmental Stress
A biostimulant is an organic material. When applied in small quantities it enhances plant growth and development. Biostimulants are thought to alter physiological plant processes and regarding turfgrass are usually marketed as soil amendments or as an additive to fertilizers. They are used to reduce environmental stress effects on grasses and have also been found to improve grass growth and root development.
Seaweed extracts, humic acids, triazole fungicides, amino acids, potassium silicate, and salicylic acid are among the natural materials have been shown to have biostimulant effects. Products that contain acibenzolar, various pigments, fosetyl and cytokinins also have stress reducing properties.
Best Management Practices
Seek out the best biostimulants by reviewing data from university studies, independent research, and talking with peers.
Include amino acids and products containing humic acids and cytokinins, such as seaweed extracts in sprays on fine turfgrass.
Begin spraying biostimulants just prior to the onset of the hottest months of the summer to condition turfgrass.
Use biostimulants as an additive to spoon feeding fertility programs for highly stressed areas like greens.
Mineral fertility inputs can be reduced when using biostimulants to help improve environmental conditions.
Calibration and Equipment
It is important to be clear on the amount of fertilizer used in any application. This can be managed through regular calibration of application equipment, administered with preventive maintenance in accordance with manufacturer’s recommendations or whenever wear or damage is suspected. Sprayer and metering pumps on liquid systems need to be calibrated regularly to save costs and minimize risks of environmental damage.
Application equipment should be selected according to the fertilizer material being used. Walk-behind rotary, drop spreader, bulk rotary or vicon, and spray spreaders all have different purposes. For example, a rotary spreader is usually used for granular fertilizers, whereas foliar feeding and liquid fertilization require use of a soluble nutrient. When applying granular fertilizer close to waterways or other non-target areas, always use a deflector shield to prevent inappropriate distribution. Avoid application onto impervious surfaces – minimize overspray and sweep granules back onto the turfgrass to reduce environmental loss and waste.
With foliar feeding and liquid fertilization, lower weighted quantities are applied at any one time, nutrients are used more rapidly, and deficiencies are corrected in a quicker amount of time. Frequent “spoon feeding” is most effective for avoiding accidental fertilizer losses to the environment while reducing potential for spikes or low growth rates that impact play, turfgrass recovery, clipping yield, weed establishment, disease outbreaks, and aesthetics.
Schedule and Timing
An application schedule by area should be developed for fertilizer application. Incorporate this into the nutrient management plan, showing the monthly amounts of N and P to be applied during the growing season. Maintain records of fertilization (including date, location, fertilizer applied, rates, grade, N source, percentage of slow-release N, form, and applicator).
Putting greens, due to their reduced height-of-cut and excessive traffic, have a higher need for growth and increased nutrition needs. Fairways and roughs generally have lower fertility requirements and require fewer nutrient inputs than tees and landing areas, which suffer constant divot damage.
Avoid applying fertilizer to soils that are at, or near, field capacity or following rain events that leave soils wet. Do not apply fertilizer when the National Weather Service has issued a flood warning or if heavy rains are likely.
Storage and Transport
Improper fertilizer storage, loading, and clean-up contribute to increased environmental risk levels. Fertilizer should be loaded into application equipment away from wells or surface water bodies. If a hard surface pad is unavailable, a tarp should be spread to collect spillage. All spillage material should be immediately cleaned up and applied as fertilizer. If fertilizer is deposited on cart paths, parking lots or other impervious surfaces, sweep the material onto the turfgrass to be properly absorbed.
