Plant nutrition

Overview

Ensuring the grass plant has suitable nutrition is a fundamental part of rugby pitch maintenance. A range of essential nutrients are required to:

• Support turf health and grass growth
• Help the pitch recover from wear
• Improve colour and pitch uniformity.

Suitable plant nutrition is achieved through the application of fertilisers which are typically available in granular or liquid form. It is important to apply macro and micronutrient packages as part of a balanced and well-developed fertiliser programme to ensure a healthy plant.

Macro nutrients are required in the largest quantity and include nitrogen, phosphorous and potassium. The percentage of each macro nutrient included in a fertiliser product is typically given as an N-P-K ratio. This illustrates the percentage the product contains by volume of nitrogen (N), phosphorous (P as P205) and potassium (K as K20). For example, A 16-16-16 fertiliser contains 16 per cent nitrogen, 16 per cent phosphorus and 16 per cent potassium. Micronutrients are required only in trace amounts.

The collection of soil samples and having them analysed in a laboratory will help identify deficiencies in the root zone and should be used to design the fertiliser programme. It’s important to note that nitrogen drives growth but is often not reported in the soil sample analysis results.

Nitrogen application guidance

Granular fertilisers should be applied using tractor mounted spreaders for covering large areas or preferably, lighter weight pedestrian hand operated spreaders. Regardless of the equipment used, care must be taken to ensure accurate application to prevent burns or missed areas which can impact turf health and pitch presentation. It is recommended that granular fertiliser is applied at half rate in two perpendicular passes.

The sustainable use of fertiliser is an important consideration when managing turf for rugby use. The basic guidance for sustainable fertiliser application is to establish what levels of nutrients are available to the grass in the root zone by laboratory analysis, then plan nutrient inputs to supplement this existing reserve as necessary, according to the growth and plant health objectives needed to sustain the playing surface.

Typically, applying fertilisers in a sustainable manner involves the application of frequent, small amounts of fertiliser. This is better than infrequent large amounts of fertiliser, even if the annual amount of nutrition applied is the same. It reduces the risk of excess leaching or run-off which could be detrimental to the environment. It is also recommended that slow or controlled release nutritional products are included as part of a sustainable fertiliser programme to prevent excessive update and reduce the risk of leaching through the pitch profile into the underlying drainage system or surface run-off.

From a sustainability standpoint, it’s important to prevent excessive uptake by the grass as this would result in short-term flushes in growth that require increased mowing and maintenance inputs. A nutrient budgeting spreadsheet is recommended to track applications and ensure the right amount and balance of nutrients has been applied.

• Prioritise organic based fertiliser, feeding the soil will help store carbon in the ground
• Look to maximise the size of your root zone as the greater the rooting system the more carbon can be stored in the surface. This may also reduce the amount of additional fertiliser that needs to be applied
• Soil conditioning fertilisers will help build a tolerance within the soil structure potentially leading to less fertilisation
• Avoid use of plastic-coated fertiliser
• Avoid the use of fungicide except in extreme conditions
• Avoid the use of pesticides by use of a long-term strategy of inputs creating an environment that pests don’t want to live in.

Spraying

Whenever you apply herbicides, fungicides, insecticides, soluble fertilisers, and soil penetrants a sprayer is used. This is perhaps the most delicate and prone to damaging grass of all the maintenance practices so proper calibration of the sprayer and staff training is key. Compliance with local regulations on the use of these substances and training of operatives is also critical.

It is recommended to test the sprayer with clean water beforehand on a hard floor to verify that all nozzles are working correctly and applying an even pattern. Nozzles must be clean and spraying a thin mist with no dripping.

Once this is tested, the product must be handled with protection equipment and diluted in water in accordance with the label instructions.

The machine must travel at a steady velocity, avoiding any stops without turning off the pump first. To avoid spraying gaps, a marking blue dye can be used or have staff members assisting with ropes or flags. It is recommended to avoid spraying on the perimeter while making a turn but shut off the pump and spray the surroundings later in a circular pattern around the pitch.

Any excess in the tank after finishing the entire surface to be treated must be disposed of in a safe manner according to local regulations. No double application until the tank is exhausted should be done as this will double the rate and possibly damage the grass.

After application, the tank must be thoroughly cleaned and rinsed to avoid leftovers that can be applied next time inadvertently.

Scarifying/verti-cutting and grooming

Overview

Organic matter removal should be included as part of a routine maintenance programme. The removal of excess organic matter from the surface and upper root zone opens the surface of the pitch by reducing turf density. It also reduces excess lateral or creeping grass growth and weakens unwanted or coarser grasses. It can also be used to improve player traction.

Cool season grasses

Thatch control must be carried out when the plant is actively growing and can be done by practices including scarifying, verti-cutting, brushing, or raking. At the end of the playing season, as part of a planned renovation process, aggressive scarification can be carried out, known as fraise mowing, which involves skimming or removing the surface to a depth of up to 20mm to remove all surface vegetation and organic matter.

Warm season grasses

When considering a programme of organic matter removal, it is recommended to carry out little and often scarification with the use of a spring-tined rake and rotary vacuum mower to keep the warm season grasses from becoming "spongy" and adversely affecting the energy restitution levels contributing to player fatigue.

Mixed season grasses

Prior to verti-cutting it is advised to cut the height of grass down to between 10-20mm in height, depending on the underlying species and variety. This should be followed by using the verti-cutting machine in two passes at 45° prior to the transitional period which is a great way to remove unwanted runners, clean up organic matter and to create a tilth in the surface allowing the new ryegrass seeds to contact the soil. All organic matter should be removed prior to over seeding.

Renovation

Overview

Renovation is the platform for getting a pitch through a season. It is one of the most important aspects for maintaining a good quality rugby pitch and in most cases is carried out every year. It is the platform for your season. Whether this is for full renovation based on last year's observations (natural pitch) or a complete rip out with specialist equipment would be the preferred choice. That said, there are several other methods that would also improve the playing surface. 

The level of renovation will be strongly affected by the maintenance completed over the course of the year. It is important that renovation is not just completed for the sake of it.

Full renovations are carried out typically at the end of every season. However, smaller renovations such as heavily scarification can be conducted several times throughout the year providing the plant is actively growing. Or if the temperatures are too hot which could cause damage to the grass plant.

A grounds-person should pay particular attention to the previous year’s pitch, therefore highlighting concerns which can be resolved or improved during the close season break. This could include installing new drains, adding secondary drainage such as sand slits, uni-drilling the pitch, or improving the irrigation system. The pitch could have too much organic matter, therefore heavy scarifying is required.

The process should be done when the grass is actively growing to maximise the recovery time. It should only be done during a period of no usage to allow the grass to establish.

Additional grass-type specific information

Grass type	Advice
Warm season grasses	Every year the pitch should be heavily scarified to prevent the runners from becoming too long. These runners can be collected and used in the thinner areas of the pitch.
Hybrid surfaces	It is highly recommended that you strip off the surface every year to ensure that the pitch is performing to its highest quality.

 

Top dressing

Overview

Top dressing is applying a layer of sand or sand/soil mix to the surface and is designed to improve surface levels of the existing soils, improve infiltration levels, provide a firmer playing surface and help dilute fine material and thatch in the surface.

Whenever possible it is strongly recommended to use a clean (salt additives can negatively affect the grass) compatible sand or sand/soil type to what is currently being used on your pitch. It is important not to use finer material than what is already on the pitch.

In addition, where possible using a USGA or DIN approved composite will benefit the surface infiltration and stability concerns. Soil sample analysis will help to match the additional material to what is already on the pitch.

Always pass a drag mat to help sand go down into the turfgrass sward and distribute it evenly, filling all possible micro depressions.

Work it into the surface to avoid smothering the grass.

Additional grass-type specific information

Grass type	Advice
Warm season grasses	Light top dressing allows stolons to move across the surface more rapidly.  Due to their prostrate growth habit, it is recommended to leave the grass to grow slightly longer prior to surface levelling of warm season grasses. This will allow quicker recovery of the grass plant.
Hybrid surfaces	Whenever top dressing of a hybrid pitch always ensure the sand application is followed by brushing or uni-raking. This will help work the sand into the profile, improving the levels and lifting the buried fibres from under the surface.

 

Aeration

Overview

Aeration is used to relieve compactions in the soil, improve water infiltration and gas exchange, improve root growth, help control thatch and change the firmness of the pitch.

Hollow core aeration and removal allows for improving soil physical conditions by exchanging soil and organic matter by sand. Solid tine aeration is more suited to sand-based pitches and is less disruptive and laborious.

Root zone if shallow, entire profile if deep. This will have an effect on firmness and should be known before completing as it may affect playability close to match-day.

Conventional aeration works to a maximum 12cm depth while deep aeration can reach a deep as 40cm. Where services are located under the field (for example, under soil heating) make sure that aeration action is not going to damage them.

For best results aerate the pitch when the season calendar permits. Aerating the surface and leaving the pitch to rest for a couple of days will aid with root development, complementary applications of root development products will also aid with root establishment.

Adding additional supplements after aeration can improve the quality of the pitch.

It is worthwhile testing the aerated area with a clegg hammer and a moisture probe before and after so that the effect of the work done can be measured and learned from.

Additional grass-type specific information

Grass type

Advice

Hybrid surfaces

Particular attention to aeration must be considered when aerating a hybrid pitch. All ground staff should listen to the advice of the installation company’s recommendations when it comes to hybrid carpets. If you are aerating a stitched pitch, be careful with the amount of heave you apply, as this has been known to open air spaces within the soil, which is a benefit, however, this method can also bury or trap the fibres.

 

Plant protection

When protecting the turf against weeds, pests, and disease, it is recommended that an Integrated Pest Management (IPM) approach is implemented. At the core of IPM is cultural management which is based on optimal management and to achieve healthy turfgrass growth, more resilient to pests and disease and limiting the requirement for any chemical plant protection products which may be harmful to people or the environment and should be avoided where possible. If they are being used, local use legislation must be followed.

It is important to understand that it is not chemical-free management. However, a successful IPM programme should result in more efficient use of pesticides, which usually means a reduction in their use. It is recommended that once a problem has been detected and correctly identified, the first course of action is to apply non-chemical control methods. Only if it’s determined that these methods are not appropriate then chemical treatment should be considered.

Non-chemical elements of a sustainable IPM programme may include:

• The use of suitable grass species and cultivars which are well adapted for the specific site conditions (see pitch design section)
• The removal of dew from the pitch surface to prevent prolonged periods of leaf wetness. This can be carried out by brushing or the application of specialist dew removal products if available (see brushing section)
• Careful management of the irrigation system. This is typically focused on reducing periods of leaf wetness which may be conducive to turfgrass disease (see irrigation section)
• Implementation of a suitable nutrition programme (see plant nutrition section)
• Implementation of best mowing practices (see mowing section)
• Use of fans to improve air movement and circulation in shaded stadium environments (see new technology section)

In addition to the above non-chemical methods, the implementation of a preventative fungicide programme may be considered as part of an IPM approach.

If chemical treatment is required, specialist products should be applied at the rates specified on the product label and adhere to national guidelines and legislation.

Specialist turfgrass products should be always used. The use of agricultural fungicide products is not recommended, and it should be noted that applying fungicide products at agricultural rates as detailed on the product label may have limited or no effect on turfgrass disease management.

Integrated Pest Management (IPM) and Integrated Turf Management (ITM) practices used to reduce input of fertiliser, water and pesticides onto turf. All inputs should be carefully recorded for future reference.

Overseeding

Overview

Overseeding originally was considered an end of season task, however over the past decade overseeding has become a weekly event. Applying seed in high wear areas will aid with the aesthetic of a playing surface and improve the stability of the playing surface.

When time is constrained, pre-germination of the seeds can save as much as a week’s time. For divot mixes, when repairing divots, it is recommended that a bag or a bucket of seed is made readily available for the ground staff to apply seed little and often when divoting the pitch. This will help keep the pitch grass percentages up during the season.

To avoid trapping the leaf and/or fibres top dress lightly or work into the soil after seeding.

It is critical to ensure you use only good quality and pure seed to reduce the risk of invasive species.

Additional grass-type specific information

Grass type	Advice
Cool season grasses	Ryegrass seed requires 48-72 hours under water after which it is rinsed, let almost dry and then broadcast on the ground.
Hybrid surfaces	Using dimple-type seeders and disc type seeders should be avoided.