Sports Turf Agronomy Advice - March 2023
February has been an uncharacteristically dry month which has meant that many have, where there have been windows of opportunity, been able to get onto playing surfaces and carry out much needed maintenance. This is essential following the wet weather experienced at the end of 2022 and early January.
We have recently had some mild weather which has led to cries of 'false spring', but when you take a look at the weather patterns over the past few years, the traditional spring period has been cold and dry, meaning little growth. Therefore, it poses the question, if the windows of opportunity present themselves early in the calendar year, should you make the most of them - as what is to follow in the coming months is not reliably going to be what is traditionally expected?
Looking ahead to the forecast for March, the start of the month is predicted to be cold. Night-time temperatures are still low, with some freezing temperatures forecast. There is also some rain present which will be welcomed by many following the dry February we have experienced, although this may fall as sleet/snow depending on timings. The low evening temperatures, coupled with relatively low day temperatures, means that growth is going to remain minimal. Similarly, nitrogen requirements by the plant will be reduced in these conditions. As we approach the second half of the month, we will see a rise in day and night temperatures, which should be when we start to see the beginning of a growth window.
With some moisture in the ground and a rise in temperatures, this period in March might be a shift towards steady growth and recovery, and when things feel like they are getting moving. There is typically a raft of maintenance work that is carried out ahead of a summer season. This ranges from small scale ongoing maintenance to the heavier duty 'corrective' maintenance, depending on the individual site and the conditions. Crucial to the success of these types of maintenance is:
- The weather, which we have no control over, but we can utilise the array of weather data now available to make the most informed decisions, such as https://academy.agrovista.co.uk/category/weather
- Applying a fertiliser with the most suitable nitrogen sources; readily available nitrogen will stimulate growth and recovery, whilst conditions are cooler.
Nutrition
Nitrate and ammonium are both readily available nitrogen sources. Nitrate is freely available for plants to uptake and can therefore stimulate growth in cooler conditions more than other nitrogen sources that are less plant available. Nitrate is highly mobile and can reach plants roots quickly, providing a quick nutrient supply. Ammonium also provides a readily available form of nitrogen, making it a particularly good choice in the early season as it's less prone to leaching than nitrate due to its positive ion charge and its interaction with exchange sites in the soil. As soil temperatures begin to increase, microbes will rapidly begin to convert ammonium to nitrate in the process of nitrification. Using a nitrogen source that is not readily available may not give the desired response and growth required. Methylene Urea (MU) is an example of a long release source of urea nitrogen fertiliser. MU's rate of decomposition 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. Organic fertiliser is composed of natural materials derived from animals and plants. Relying on natural biological and chemical processes, nutrient content tends to be lower, less exacting and released much slower than conventional fertiliser products. As the nutrient release is slower, so is the turf response. For those not carrying out maintenance work where recovery from surface disruption is required, liquid applications of fertiliser to coincide with the increase in temperatures may be adequate to gently 'wake up' the turf and give the necessary response ahead of subsequent granular applications later in the spring, when temperatures have risen further.
Biostimulants
Applications of biostimulants will be beneficial to the plant and soil; with an increase in daylight hours, the rate of photosynthesis starts to increase and so will the requirement of energy from the plant. Therefore, applications of carbon in the form of simple and complex sugars can act as a readily available 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, encouraging the breakdown of organic material.
Plant growth regulation
Poa annua seed head development can start early, and this is also a big consumer of the plant's energy requirements. Applying a plant growth regulator that is formulated to work at cooler conditions, such as prohexadione calcium, to interfere and suppress the development of the reproductive seed, can then help re-direct this energy away from seed head production into other plant development processes, improving overall plant health at a time of plant stress.
Ecology
As we march closer to spring and step closer towards summer, listen out for the familiar bzzzzzzing sound of the hugely important bee. There are numerous campaigns running nationwide to encourage bee populations; if we can encourage environments where they can thrive, we can help protect their future as there is such value placed on their existence…for ours!
Wildflower mixes are brilliant for bringing bio-diversity, colour and enjoyment to landscape areas and spring is the perfect time to sow many of the different mixes that are available.
Tom Wood
B.Sc (Hons) | BASIS | FACTS