4turf® – prepare for the drought to come

As droughts are becoming more common, greenkeepers need to start future-proofing their golf courses. Deep-rooting, drought-tolerant turf grasses such as 4turf® (turf tetraploid perennial ryegrass) may be one of the solutions. 4turf® stays green and playable with less need for irrigation during long, dry periods.
DLF have undertaken research at the RadiMax state-of-the-art root-screening facility, where plants below- and above-ground tolerance were tested. The results show that 4turf® outperform diploid perennial ryegrasses when it comes to drought-tolerance. 4turf® has deeper roots and a better visual appearance even when plants were starved of water.

The importance of roots
With climate change we are facing two types of stress that will have detrimental impacts on turf growth. Where most plants or trees form new shoots at the top of the plant, grasses develop new shoots very close to the roots. It suggests that roots play an important and unique role for grasses and it is a mechanism that helps the grass survive several kinds of stress.
Under drought, soil always dries out from the top. As drought progresses down the soil, the first line of defense the plant will embark on, is its deep root mass, which allows it to continue taking up water and nutrients. While this mechanism does not enable the grass to economize with its water supply, it does allow the grass to prepare itself for even worse conditions. Once drought has progressed below rooting depth, the grass will need to rely on other defense mechanisms.

Spring and summer drought
We do talk about two types of drought, spring drought and summer drought. Spring drought is a phenomenon that occurs with increasing frequency in the northern countries of Europe. Summer drought is typically a phenomenon in southern Europe but there are increased cases of summer drought in northern Europe.
Spring drought is characterized by the fact that despite lack of precipitation, there is still water deep in the soil. Therefore, grass varieties that quickly develop larger root systems in the spring are better able to survive this type of drought.
In a summer drought, all water is used up throughout the soil profile. In this situation most grasses will go into hibernation. Closure of stomatal cells, through which the plant normally “breathes CO2 in and O2 out”, will immediately shut down transpiration – and with that – also any further growth. Some species also have thicker leaves and/or wax layer that will help them save further water. Shutting down transpiration on a sunny day, however, does not come without a penalty: The photosynthetic machinery will still be bombarded with photons from the sun but now without cooling. The result is leaf wilting and – if prolonged – plant death.

Root screening
In the RadiMax screening facility, plants can be characterized both with respect to root profile and above-ground tolerance. The perennial ryegrass varieties that have been selected though this intensive drought regime and proven to have the highest root mass in deeper soil layers are 4turf® varieties. The results show that tetraploid perennial ryegrasses outperform diploid perennial ryegrasses for drought-tolerance. At RadiMax we saw how deep their roots reached, and how green the turf remained when the plants were starved of water.
The secret is in the springtime speed with which 4turf® varieties quickly develop their strong roots. Compared to diploid perennial ryegrasses, 4turf® has a quicker root growth and development of a larger root mass in the upper layer of the soil, and it has a higher above-ground drought-tolerance. This makes 4turf® the clear winners when it comes to drought. 4turf®’s ability to quickly develop strong roots and establish a larger root mass in the spring is the best protection against a spring drought. Later in the season, their above-ground drought-tolerance combined with their exceptional root mass gives outstanding tolerance to a summer drought. Trials conducted in France and the Czech Republic confirm that, after a summer drought, 4turf® plots look greener than those of diploid perennial ryegrasses. With irrigation costs rising significantly in 2022 and with the real risk of outright irrigation bans being a genuine fear for many, making the change to DLF 4turf® perennial ryegrass has never made more sense !

4turf® for golf courses
Prolonged periods of severe drought also bring the specter of drinking water being banned for the irrigation of golf courses. With many greenkeepers looking to alternative water sources like reclaimed or recycled brown water, salt tolerance becomes a bigger factor. DLF have been screening all turf cultivars for salt tolerance for many years as we saw restricted water supplies becoming a greater issue. In testing, 4turf® cultivars are proven to have a higher tolerance to salt compared to diploid perennial ryegrass, making them the perfect future proof solution on fairways and tees for modern sustainable turf managers.
By choosing 4turf® for your golf course, you also get the highest disease-resistance and the quick establishment of 4turf® will keep out weeds.

Don’t forget the management The final step in preparing for a drought is to choose the right management. Avoid cutting the grass too short. Longer leaves will prevent cell damage in shaded leaves and will also ensure that photosynthetic products can still feed the roots, which will keep them alive for when rain returns. Reducing cutting during drought will not only help your turf, its also going to reduce your mowing costs and your carbon footprint.

Remember that sustainable solutions don’t have to mean poor quality, on top of their environmental credentials the latest 4turf® cultivars from DLF like Fabian are now fine, dense and have excellent wear tolerance so you no longer have to sacrifice quality to deliver a sustainable product. Making the switch to 4Turf means that come the next drought the once thing you won’t be sweating over is your turf.

NewsApr 28th, 20230 comments