Sports Turf Agronomy Advice - February 2023

Following the poor weather we have experienced throughout December and January, it feels like February has jumped upon us. The constant rainfall, followed by freezing temperatures, has restricted the amount of work that could be done on turf surfaces over recent weeks. It has, however, hopefully given some areas a partial rest from the wear and tear of play, after an uncharacteristically mild and busy November.

For those who were able to attend the Bigga Turf Management Exhibition in Harrogate, I'm sure you had an informative and rewarding experience, with many colleagues reporting there was a 'buzz' around the halls, after a few years of change. If you have yet to attend BTME, it is worthwhile making the trip to experience the best of our turf community.

An overview of the weather statistics for January can be found below. The first half of the month brought warmer temperatures, but wetter conditions compared to the last half of January when temperatures dropped alongside rainfall. As expected, there has been a minimal requirement for nitrogen by the grass plant with growth potential remaining low (below 50%).

Click here if you want to review weather data in your region for January. To keep up to date with the weather throughout February visit https://academy.agrovista.co.uk/category/weather

It is nice to get things moving in February and feel that progress towards growth, recovery and surface improvements is being made. Although technically and traditionally still classed as a winter month, February can provide windows of opportunity, which can allow some agronomic activities to be carried out, that typically wouldn't be done until a couple of months later. Using Leeds as an example (a generic, central location in the British Isles), day length on the 1st February will be 8 hours 54 minutes and the sun's altitude from the horizon will be 11.65°. At the end of February, this changes to around 10 hours 47 minutes and the sun's altitude from the horizon will now be 20.46°. That's a difference of 1 hour 53 minutes and an altitude difference of 8.81°. This means from the start to the end of the month, you gain approximately 2 hours of sunlight and a large increase (around 57%) in the height of the sun at mid-day, which is vital for gains in photosynthetic rates.

The forecast for February is mixed, with a mild start to the month, which may feel like a false spring. Although, towards the middle of the month, night temperatures are predicted to drop down to near 0°^c which will have an impact on growth. Day temperatures increase back up to around 10°^c near the end of the month, but there are also several days of rain forecast. It is important to remember that unless you have the means to artificially stimulate growth (grow lights, under soil heating), it can't be forced if the right environmental conditions aren't present. Data is ever increasingly being used within our industry as a predictor of what is to come, to help us make more informed choices. And with that, growth potential is an excellent model to utilise throughout the year; but specifically early season/spring to get the most effective nutrition applications and timings.

What is it Growth Potential?

Growth potential (GP) is an expression of the relative growth rate of turfgrass at a given temperature. Optimum temperatures for turfgrass growth are generally considered to be in the range of 16 to 24°C for cool-season grasses. It is therefore possible to model the potential for the grass to grow at any temperature. A value of 0, meaning no growth is possible, through to 1. At a value of 0.5, the GP predicts that temperatures are adequate for growth at 50% of the plant's maximum growth rate; and when the GP is 1, grass has the potential to grow at its maximum rate (Woods, 2013). Timing fertiliser applications to coincide with growth potential can therefore help maximise fertiliser use efficiency. It can also inform when any maintenance work may be scheduled to ensure a quicker recovery time.

Nutrition

Typical requirements for nutrition will be low this month; utilising growth potential information will allow accurate applications. The decision might be taken that recovery needs to be boosted to improve playing surfaces. Utilising the right nitrogen source will be key to ensuring that the nutrient is plant-available. If conditions allow, liquid applications may be more suitable for quick plant uptake and an immediate response. The addition of Iron may be beneficial if there has been any moss ingress over the winter months, where there has been low light and swards have thinned.

Pests

Syngenta may have some positive news regarding pest control. Updates to follow, following any announcements.

Tom Wood
B.Sc (Hons) | BASIS | FACTS