Sports Turf Agronomy Advice - April 2023

Tom Wood B.Sc (Hons)in General Interest

The end of March feels like we have finally seen the end of the unfavourable weather conditions and what has felt like a mixed bag of all weathers, snow, frost, rain, sunshine and winds, all making managing playing surfaces and preparations that bit more difficult.

April brings with it a real feeling of spring, mainly helped by the changing clocks and longer, lighter nights. A slight increase in temperatures has started to take the edge off the cold and we are now seeing soil temperatures start to rise and some essential turf growth and recovery from winter play. Although never far from the back of my mind is that there has been snow in April in the past, so we must not get too carried away, but fingers crossed, not this year.

An overview of the weather statistics for March can be found below. The first half of the month had cooler temperatures and wet conditions compared to the second half where temperatures rose alongside a further increase in rainfall. There has been some requirement for nitrogen by the grass plant with growth potential increasing to around 50% by week 12, it is expected to stay around this figure for the coming week.

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

Looking ahead to April's long-term forecast, temperatures throughout April appear to be fairly conservative with only 5 days predicted to be 12°C or above, a further key factor here is that night temperatures are also remaining relatively low, with 25 out of 30 days at 4° or below. This will be reflected in the daily growth potential staying fairly consistent in line with the end of March, therefore growth will be steady rather than strong. Furthermore, weeks two, three and four appear dry and this may also impact on growth. Ensuring even moisture distribution in the rootzone through the suitable use of wetting agents can be beneficial.

Wetting agents

When using this technology there is a benefit of ensuring applications are made early. This helps ensure the product is in the profile before issues can arise. Recent years have seen dry conditions early in the season, they can lead to playing catch up in terms of having consistent moisture within the profile. Managing moisture in this way allows turf managers to have better control over the conditions. This can encourage rooting deeper in the profile, allow less water to be applied via irrigation systems and allow better uptake of nutrients by the plant and therefore better efficacy of any product applications that have been made. Each site will be different and there are technologies within the market which will suit individual sites with individual needs.

Wetting agent technologies

Wetting agents should be used in accordance with the desired outcome as not all wetting agent products utilise the same technologies. Similarly, you may not necessarily want to use the same wetting all year round. Wetting agents can be split into two groups, anionic or nonionic. The anionic wetting agents are the original technology developed in the 1950's which are negatively charged. These can cause dispersion within clay particles and have negative impacts in soil.

The nonionic wetting agent group can be further split into two more generic groups. Polyoxyethylene (POE), which also originated around the 1950's and a newer group of block co-polymers developed in the 1990's. Care should be taken when using products that utilise older technologies as issues of phytotoxicity can arise, depending on applications rates, grass species and environmental conditions.

Block co-polymers are now commonly used and are safe on fine and sports turf areas. They help to reduce water repellence issues in rootzones and soils, improve soil water content and the amount of plant available water. Within the category of block co-polymer you have, straight block co-polymer to enhance water movement into the rootzone and reverse block co-polymer (retainer) which enhance moisture retention in the rootzone. Blends of both, straight and reverse block co-polymer are now commonplace within the industry, which aim to utilise the benefits of both technologies.

Other products available include those containing Alkyl Polyglucosides which make use of a sugar molecule reacted with a fatty acid to reduce water repellence. These can be mixed with straight block co-polymers and are widely used in the turfgrass industry. Lastly there is the unique modified methyl capped block co-polymer which creates a thin film of water around the soil particle which reduces the ability of the soil to completely dry out, meaning low volumetric water content can be achieved without becoming hydrophobic. Determining what the goal is for your site in relation to water management and distribution is key to deciding which technologies are going to help you achieve it.

Nutrition

As daylight hours are increasing, applications of simple sugars and carbohydrates can provide the plant with a readily available supply of energy, which can be much needed at a time when growth is commencing and can assist in reducing any additional stress. As can choosing an appropriate fertiliser with a suitable nitrogen source for the time of year. If growth is not strong because of environmental conditions, applications in small amounts of readily available nitrogen can be used to keep a constant but low supply of nutrition, which supports healthy growth. Alternatively, a granular application with a portion of slow-release technology could be used, which will provide nutrition gradually over a longer period, depending on the environmental conditions and will not release immediately giving an unwanted flush of growth. Typically, part of the formulation will depend on microbial activity to breakdown the technology to urea which once converted via further processes to ammonium and nitrate can be taken up by the plant.

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