Key Tasks for March
With the relaxation on restrictions for outdoor sports at the end of March, you can begin to get your greens ready in preparation.
Your number one priority is to keep safe.
The emphasis at this time of the year will be on mowing frequency, as long as there is sufficient moisture within the soil.
Mowing. Greens should be mown at least three times a week, with some grooming, verti-cutting or brushing being undertaken on a weekly or twice weekly cycle to improve air movement and reduce thatch levels building up in the sward profile.
The sward will be actively growing due to the increased soil temperatures, coupled with the stimulation of fertiliser applications. Regular mowing will be required to maintain sward height at around 4-5mm. Verti-cutting/grooming fortnightly can be carried out to help speed up the green and help improve the health of your turf.
Aeration should continue, using a mix of micro, needle or star tines which give maximum effect and almost zero turf disturbance.
Regular use of a sarrel roller will be beneficial and the use of micro tines to aerate the green will help reduce soil compaction, 'vent' the root-zone and to allow water to move quickly from the surface and into the root-zone, thus encouraging the turf to root deeper.
Irrigation: Soil and air temperatures usually increase in April, often bringing on the need to irrigate. If soil profiles, particularly sandy soils, are allowed to dry out too much they often become water repellent (hydrophobic), a state when soils can become difficult to re-wet. Often the first areas to suffer on greens, particularly crown greens, are the high spots on the green. You may need to spend more time hand watering these problem areas.
When you do water, ensure you go to a depth of 100-150mm to encourage the roots to go down to find the water.
I started last month’s diary looking towards the weather hopefully starting to improve by the end of February, and thankfully it has. However, that doesn’t mean we can ignore the poor weather that has been before. The cold continued from the end of January and well into February with more freezing temperatures and snow cover, meaning prolonged issues for turf managers. Fortunately, the temperatures started to rise at the back end, and it felt like the ‘false spring’ had arrived. This has allowed many turf mangers to get some much-needed work carried out on surfaces. Although not the typical time to carry out ‘extensive’ work, there are many examples of success with utilising this method. There are undoubtedly though, also some examples of this being unsuccessful and highlights the point that everyone has different circumstances and we must try and do what is best for our turf on our site.
March’s forecast looks unsettled, which is typical for this time of year. The start of the month, moving towards the middle, looks fairly settled with sunshine and showers, combined with favourable daytime temperatures, which should be encouraging for early season growth and recovery. The predicted night-time lows will restrict any great increases in growth potential and therefore fertiliser applications should be made with this in mind, with caution at making unnecessary applications of excessive nitrogen. Then towards the back end of the month it is forecast to be unsettled with multiple days of rainfall predicted. This coincides nicely (not) with the upcoming commencement of outdoor sports, following the government’s latest COVID-19 lockdown restrictions update, allowing organised adult’s and children’s sport to take place from the 29th March, which will be welcomed by us all I’m sure.
Although I can imagine everyone is desperate to get back to doing the things they most enjoy, such as participating in sport, the date given allows turf managers some time to prepare for the return of sporting activities. The plant will have been under considerable stress, given that the ground in many locations has been saturated for some time and has undergone periods of snow and frozen ground. With the return to play approaching, many will look to carry out maintenance work that would typically be done later in spring, with a view to minimise any disruption; here the key is striking the balance to ensure there will be adequate recovery from the work carried out in time for when play returns. If this isn’t likely, then planning the work when conditions will be more favourable, with decent soil temperatures and more daylight hours, is a reasonable approach.
Selecting the ‘right’ fertiliser at this time of year is critical to ensure that the turf is encouraged to recover from the stresses of the winter, without unnecessarily trying to force growth that just isn’t realistic if the environmental conditions aren’t advantageous. This will give the turf a gentle wake up and help ensure optimal turf health moving through spring. The type of Nitrogen source(s) within the fertiliser will play a major role in this selection;
The nitrogen available from potassium nitrate or calcium ammonium nitrate, for example, is freely available for plants to take up, and for this reason it can be useful where rapid or immediate growth is required. This also makes it particularly useful in the winter and early spring where its availability can stimulate growth under colder conditions. Nitrate is highly mobile and will reach plant roots quickly providing an almost instant nutrient supply.
The ammonium form of nitrogen is typically used in the amenity industry as ammonium sulphate, also called diammonium sulphate or sulphuric acid diammonium salt. Fertilisers containing nitrogen in the ammonium form provide a readily available form of nitrogen and this also makes it particularly good in cool conditions with average to low growth potential, as grass will utilise nitrogen in both the ammonium and nitrate forms, its ability to fix to soil minerals makes it less mobile than nitrate. In warmer conditions, microbes will rapidly begin to convert ammonium to nitrate in the process of nitrification.
After application, urea first needs to be broken down by naturally occurring enzymes called urease to ammonium before it can be utilised effectively by the grass. As this process occurs rapidly in warmer temperatures, the grass is provided with an easily available source of nitrogen, although it becomes more limited during the colder winter months when growth potential is lower. The ease at which urea becomes soluble also makes it both an ideal liquid fertiliser and granular product. However, during the process of transformation, during the warmer temperatures of the summer months, urea can be prone to volatilization losses and this can make it less efficient than stabilised forms of this nitrogen source.
Urea Formaldehyde (Methylene Urea)
This is an example of a long release source of urea nitrogen fertilizer. Urea formaldehyde’s rate of decomposition into carbon dioxide (CO2) and ammonia gas (NH3) is determined by the action of microbes found naturally in most soils. The activity of these microbes, and therefore, the rate of nitrogen release, is temperature dependent. The optimum temperature for microbe activity is approximately 70-90 °F (approximately 20-30 °C) making this an ideal choice during high levels of growth potential.
An organic fertiliser is composed of natural materials derived from animals and plants, but they may also be from mined minerals e.g. rock phosphate. Relying on natural biological and chemical processes, nutrient content tends to be lower, less exacting and released much slower than conventional fertiliser products. However, many amenity fertilisers are also a blend of inorganic and organic forms and provide a broader range of benefits with regards to nutrient availability and soil microbiology.
Applications of biostimulants will be beneficial to the plant and soil as the rate of photosynthesis starts to increase, so will the requirement of energy from the plant. Therefore, applications of carbon in the form of simple and complex sugars can act as an energy supply for the plant and help reduce any stress from any maintenance works carried out. As the soil becomes more active with temperatures increasing, the carbon will act as a food source for the soil microbes and increase soil activity. Poa annua seed head development can start early and this is also a big consumer of the plant’s energy. Applying a plant growth regulator early to suppress the development of seed heads can help re-direct this energy away from seed head production into other plant development processes.
As we head into March, we move ever closer to hearing the synonymous ‘buzz’ of summer from the humble bumble bee. But as more and more species are becoming extinct or highly endangered, will this sound always be around in the future? There are numerous campaigns running nationwide to ensure the future of the bumble bee. Remember, one in three mouthfuls rely on pollinators, therefore if we can encourage the environments which they thrive in, we can help protect their and our futures. Spring is the perfect time to sow a wildflower mix and they can really transform areas into a bio-diversity haven that is also great to look at and enjoy.
- Keep machines overhauled and clean.
- Inspect and repair any watering or irrigation systems.
- Continue to check and service your floodlighting systems.
- Replace any worn tines on your aeration equipment.