This is a hugely important area of greenkeeping, that if followed correctly can make life a lot easier for the greenkeeper. For a lot of people involved in greenkeeping within pitch and putt, they can feel in over their head when it comes to plant nutrition. This is completely understandable, the experts in this field will have Bachelor of Science (Hons) in sportsturf science or similar qualifications. It is an extremely long and complicated science.
The aim of this piece is to give a broad view of the topic and to simplify as much as possible. The topics that will be covered are:
- Soil sampling, results, and regimes (programmes)
- Plant uptake of nutrients through root (granular) and leaf (foliar)
- Different type of fertilisers
- Other chemicals available
- Crunching the numbers
For turfgrass to grow to its full potential, dry matter/soil holds 16 nutritional elements that are essential for it to seed and flower. These are broken down into two categories, Macro nutrients and Micro (trace) nutrients. The Macro are broken into two groups, Primary (Largest) and Secondary (Medium).
Macro (Primary) Nutrients
These are the three nutrients you will be most familiar with, Nitrogen, Phosphorus, and Potassium, otherwise known as N.P.K. These letters are their chemical symbol on the Periodic table of Elements. They mostly take the first letter as their symbol, but for Potassium “K” is used. The plant needs these in nutrient in large amounts.
Controls the metabolic processes required for plant growth. Proper applications of N increase density of the sward (coverage of grass), which in turn adds strength and allows for more wear and tear and ability to recover. A turf with an N deficiency will have a yellow colour.
The plant cannot grow without a reliable supply of P. It is essential for the photosynthesis process and it effects protein synthesis and is vital for rooting and root growth.
This regulates the opening and closing of the stomata (breathing pores on the leaf), which allows the exchange of gases and oxygen. It also regulates water during transpiration and increases drought tolerance.
Macro (Secondary) Nutrients
The amount required of these nutrients is between the Macro and the Micro. These consist of Calcium, Sulphur, and Magnesium.
Ca regulates transport of other nutrients into the plant and is also involved in the activation of certain plant enzymes. It is an important part of cell wall structure and strength in the plant. Only N and K required in larger amounts by plants and every plant needs Ca to grow.
It is becoming known as the fourth primary element macronutrient along with N, P, and K. Its role is to conduct photosynthesis, where is captures Chlorophyll which captures energy from the sunlight and stores it while freeing oxygen and water.
MG is also an important part of Chlorophyll, which is also a critical pigment important in photosynthesis.
Micro (Trace) Nutrients
Although these are only applied or found in trace amounts, if applied in large amounts without having done tissue or soil samples, can result in toxic accumulations which can cause serious plant injury.
Fe is associated with turfgrass colour and can also improve frost resistance during winter.
Is important for sugar consumption. It is also important for uniform growth and cell elongation.
Essential for photosynthesis and a component of certain enzymes.
Influences photosynthesis and rate of growth of turfgrass.
Component of enzyme that reduces nitrate in plants.
Plays a role in DNA synthesis and translocation of sugars.
Plays a role in photosynthesis.
Although not a nutrient, I will just mention Ph at this stage. Ph is the measure of the degree of acidity or alkalinity of a soil/rootzone. It is the measure of Hydrogen cations in the soil and the potential for fertility. It ranges from 1-14. Below 7 is Acidic and above 7 is Alkaline. For fine turfgrass we ideally would like 5.5-6.5 but a lot of Irish soil is 7-8 which is just about manageable. A good balance is in the middle, 6-7.
Not only are these needed for plant development but how they interact with each other determine how they can be taken up by the plant. By that I mean, a large amount of one nutrient can make another nutrient less available or deficient. Your type of soil and the Ph can also determine how available or unavailable these nutrients are. The CEC (Cation Exchange Capacity) is a measure of the potential nutrient retention in a soil. Obviously, we will never know what exactly is in our soil by simply looking at it, but this shows us exactly why soil testing and sampling is vital if we want a healthy sportsturf to play on and maintain. I do stress you do not need to fully understand all the above, but a general understanding will help when talking to Chemical company reps or agronomists especially when discussing a fertility programme.
Thankfully, this is the end of the scientific section, if you do have an interest in this side of things, there is an abundance of websites and books that go into more detail.
Soil Sampling, Results and Programmes
Now that we know what nutrients are needed for healthy plant growth, we need to find out what the nutrient levels are in our soil/rootzone. There are several chemical/fertiliser supply companies around Ireland, the ones I am familiar with would be Cropcare, NAD, and Turfcare. I have dealt with Cropcare for many years and find them to be excellent for both delivery of products as well as technical help. One service they provide is soil sampling. I would urge you to find out of your supplier if you can avail of soil sampling through them or you may have to do it independently. As far as I am aware a test costs approx. 100-200 euro if done independently. You should have results back within 2 weeks.
Collecting Soil Samples
There is little work involved in collecting the samples and posting them off. Your fertiliser supplier may supply you with small bags. These bags will have a line on it that you must fill too, but not above, and then seal the bag.
When taking a sample,
*Use the soil sample probe that we spoke about before, go to a depth of approx. 2”-4” (50-100mm). For a pitch and putt green, I would aim to take between 6-10 samples per green.
* Use a “W” pattern when extracting cores.
*You can group a few greens together in one bag, for instance I would group 4-6 greens that were built in the same year. If you have a problem green, you could do a bag on its own for this one green and then compare results to other greens.
*It is particularly important that you label the green/hole number on the bag or if a few greens are in a bag be sure to label all greens/hole numbers on the bag.
*Another important thing to do is cut off leaf blades and thatch off each sample with a scissors. This test is for soil only.
*The timing of the test is also important, leave until your turf is due a feed and take samples the week before you apply the feed, this is so the turf does not have an abundance of any one nutrient after an application.
*Also, be sure to do a soil sample at the same time of year, every year or every second year. Many clubs do this just before their annual Spring aeration programme.
Soil Sample Results & Regimes (Programmes)
With Cropcare, and I presume other companies, the results will be sent directly to them. They will analyse the results and then send you a copy of the results along with a suggested feeding regime/programme. It could not be more simply.
When deciding on a regime the main factor for you to decide is if you want to use a granular or foliar regime or a regime that incorporates both. From a pitch and putt perspective, most of if not all clubs will have a pedestrian spreader but may not necessarily have a pedestrian sprayer. It is a case of, use what you have at your disposal.
When speaking to the company rep or an agronomist, they may also advice on adding in other treatments such as wetting agents, plant growth regulators (PGR) or dew control chemicals into your maintenance regime. Again, from a pitch and putt perspective this may come down to grounds maintenance budget of your club or even whether you have a pedestrian sprayer to apply these products.
The first 3 illustrations are a soil sample result and comments from 2014 followed by a treatment regime. Understanding the number levels is not overly important but the comments sections explain the findings. The other sections, rootzone characteristics, rootzone quality indicators and nutrient tested can be followed and gives an idea of the levels and where improvements can be made. The second 3 illustrations are from 2019 with a treatment regime for 2020. It is good to compare results to see where improvements have been made where some need to be made.
The treatment regime also has a comments section which explains the regime. The 2014 regime has a good mixture of granular and foliar applications. The 2020 regime has mainly granular applications with just one liquid application. This was done out of convenience from a time perspective. You can see how the
- how much total nutrient input in kg per hectare for the year in red numbers N, P, K, S
- product name
- the application rate
- number of applications per year
- pack size in weight or litres
- packs required
- how much nutrient input per hectare per application
- timing of application is determined by the location in a month shown. Start, middle or end.
This is also a great tool for budgeting, you can calculate how much money it will cost for per year for fertiliser and chemicals. There are many clubs not availing of this service from chemical companies and as you can see most of the work is done for you. Hopefully having read the DCB maintenance programme to date you will have a better understanding of nutrition and of the language being used.
Plant Uptake of Nutrients, Roots (granular) & Leaf (foliar)
This type of fertiliser is applied in granular from, which is applied with a pedestrian spreader. When applied, it breaks down/dissolves when it meets either rain or irrigation. As it breaks down into the soil it becomes available for root uptake. This can take a couple of days and you can start to see the effects within approx. 7 days.
This is a very time efficient way of applying fertilising; it can take approx..30-45min to fertiliser pitch and putt greens. The method is, fill the hopper with the product, set the cone and spinner setting, this information will be on the product bag. Your walking pace and ability to get a proper over-lap are crucial for an even application. Be sure to wash out the spreader when finished and wear PPE (personal protective equipment) when using spreader. Most products will need to be watered in within 24 hours, so check weather forecast ahead of applying to see if rain is due. This a very cost-effective way of feeding sportsturf.
Accidents can happen, always fill the spreader hopper away from the area you are fertilising as to avoid a spillage, if you do have a spillage, immediately clean as much of the product up as you can, if you have a blower, blow the area, and then aerate and water this should limit the amount of burn damage. Never open or close the spreader on the green and always continue walking for a step or two after closing the spreader, if you open the spreader and then walk you will get an extra application at the start. All fertiliser applications should be recorded in written form.
This type of fertiliser is applied in liquid form, which will be applied with a pedestrian sprayer. When applied, it becomes available and is absorbed up by the leaf. This is done by the stomata, which also controls the oxygen and water intake of the plant. Effects of foliar feeding can usually be seen with 48 hours and sometimes quicker.
This type of application I find, from a pitch and putt perspective can be very time consuming. It can take anywhere from 1.5-2.5 hours to spray pitch and putt greens depending on how many products and in particular the tank size of your sprayer. You will apply liquid feeds on a more regular basis than you will apply granular, in some cases you could be spraying every 3 weeks compared to spreading every 6-8 weeks.
Most pedestrian sprayers have a 25-litre tank which will have to be fill 2-3 times depending on the size of the greens, there are some companies that sell 50 litre tank sprayers. There are also knapsack sprayers available but with smaller tanks. These can be a great purchase if keeping an eye on finances.
Time and care must be taking when preparing to spray, from suiting up in PPE, including wetsuit and spraying mask apparatus, to mixing the correct amount of product with the correct amount of water. Making sure that it is mixed thoroughly before being applied. The walking speed must be deliberate and consistent for effective application. Cleaning of sprayer and nozzles must be done after every spray application and done in a safe manner as well as the disposal of any unused chemicals. I would recommend steel units to store chemicals for safety reasons as well as their financial value. A spraying certificate is required for application of fungicides, herbicides, and selective herbicides. All spray application should be recorded in written form.
The main difference between granular and foliar feeding is how long each application will last.
With most granular fertiliser applications, they are generally designed to last 6-8 weeks, with an initial growth spurt which then lessens as the weeks go by. There are slow and quick release options available but generally they will start with an initial growth spurt, which can cause us to have lush and succulent grass growth which is not always ideal for a fast firm putting surface, which as we have seen in an unhealthy turfgrass can lead to disease outbreaks.
The idea behind foliar fertiliser applications, is that we can put a reduced application on but do it regularly enough so that we do not have this initial growth spurt, “little and often”. It is a much more accurate method in its uniformity of application compared to spreading. The other benefit as stated is how quickly it can have an effect.
If you have both a sprayer and spreader, talk to your chemical supplier or agronomist for advice on which direction to take. Make sure at this stage that you know how many square meters your greens are as this will be one of the first questions, they will ask you before making a regime for you as well as the soil/rootzone and grass type you are working with. Different Types of Fertilisers & Products
Different Types of Fertilisers & Products
Next, I will give a brief rundown of the different types of fertiliser and products available and how they can help us achieve a healthy and fantastic looking pitch and putt course. I would recommend getting a copy of a product guide from your chemical supplier, they will give a list of products but will also give descriptions and information on the products which will hopefully give you a better understanding of them and the language used having read the first four parts of this maintenance programme.
For both liquid and granular, there are similar types of fertilisers most of which are dependent on soil temperatures.
Slow Release (SRF)
These are fertilisers than release a small, steady amount of nutrients over a course of time. Will have less control over the release of the nutrients. One main benefit of them is they have a low risk of fertiliser burn. This is done by having both small amount of quick release for an initial growth spurt and a larger amount of slow release. Release over 5-7 month.
Controlled Release (CRF)
These release nutrients gradually into the soil over a period. 2-3 month.
These release their nutrients immediately after application as do liquid fertilisers.
They release their nutrients over slower period of time, along with SRF and CRF this is the most consistent and reliable way. Organic fertiliser is composed of processed plant and animal matter that provides useful nutrients and improves the structure of the soil.
These are products that are dissolved in water and applied in liquid form.
Fine Turf /Outfield
Within the above types of fertilisers, they will also be broken down into two groups. 1, fine turf, generally 3mm-12mm height of cut (greens/collars), these will be small granules with some almost like dust. 2, outfield (fairways/rough), these will be larger granules in size.
Then within these, they will be broken down in Spring/Summer and Autumn/Winter. One of the main differences between these two will be the nitrogen content. More in Spring/Summer and less content in Autumn/Winter.
There are other products available that are useful and affordable for pitch and putt clubs but that require a sprayer to apply. Chemicals such as:
Liquid Turf Hardener, to strengthen turf and increase plants ability to withstand stress and improve disease resistance.
Seamac Proturf, which has iron for green up affect along with micronutrients and seaweed extract.
Sulphate of Iron, a powder form of iron that must be dissolved, great for green up and for moss control.
Liquid Iron, exactly what is says, a straight up liquid, again great for green up prior to a competition.
DewCure this is a product for dew control, formulated to reduce the accumulation of surface moisture on turf. Fusarium disease is positively linked with conditions conducive to high leaf moisture levels and therefore by reducing the level, disease activity is suppressed.
There are plenty of other products available for a number of purposes, other chemical companies will have their own products, some will give the same affects but will be under different names. These products guides can be a great source of information and again these companies have sales reps and agronomists on hand for any questions you may have.
Crunching the Numbers
All the numbers on products can be confusing until you get used to dealing with them. Most application rates are in hectares, 10,000 sq. metres. The average for a pitch and putt course would be 1,000 sq. metres, so usually divide the application rate on products by 10 and this will help getting used to them. Next is the N, P, and K. For example, a bag of fertiliser with analysis 6-5-18 contains 6% Nitrogen, 5% Phosphorous and 18% Potassium. If your bag weighs 25kg, there will be 1.5kg N, 1.25kg P, and 4.5kg K. This adds up to 7.25kg, the rest is made up fertiliser technologies for the control releases as well as anti-caking additives and conditioners.
To calculate the amount of nutrients applied per area, multiply the application rate by the nutrient content. For example, 6-5-18 with an application rate of 25g/sq. metre,
Convert application rate from g/m2 to kg/ha, 25g/m2 x 10=250kg/ha.
Multiply product rate (kg/ha) by % N content, 250 x 6%=15 kg N/ha.
Divide 15kg/ha by 10 for kg/1,000m2, 15/10=1.5kg as was shown in the breakdown of the bag above.
When working out for liquids, a litre of water will weigh 1kg, other liquids may weigh. The specific gravity (SG) which will be on the product container, an SP rating of 1.5 means that it is able to effectively carry the weight of a liquid 1.5 times the weight of water.
To calculate nutrients applied for an area, application rate by the SG by the % nutrient content/100=kg/ha nutrient. For example, 16-4-8 with an application rate of 60l/ha.
Specific Gravity (SP)=1.24 kg/l (1 litre pf product will weigh 1.24kg)
Calculate weight of liquid applied per ha. 60 x 1.24=74.4 kg/ha
Multiply product rate (kg/ha) by % N content, 74.4 x 16%=12kg N/ha.
Repeat this calculation for the Phosphorus and Potassium. Once you do a few of them you will pick it up.
Finally, I hope this part has helped you to understand a bit better the plant nutrition and the programmes that go into managing sportsturf and in our case pitch and putt greens. It is a complicated subject that is a multi-million-dollar industry that I believe, to achieve quality greens all year round we must use to our benefit, by means of getting soil samples done and use the professional advice on hand to formulate maintenance and feeding programmes.