Turfgrass

Turfgrass is a high-maintenance crop that differs from traditional agricultural crops because, unlike other crops, the product is not what is harvested but what remains in the field (Cereti, 1993).

 

A turfgrass consists of continuous and uniform herbaceous vegetation subjected to frequent mowing (Beard, 1991). It is typically used in urban environments where it performs a series of high-impact environmental functions. If properly managed, turfgrass can produce numerous essential benefits.

 

It has been demonstrated that its presence helps to reduce peak summer temperatures (Croce et al., 2006), surface water runoff, and soil erosion (Argenti et al., 2011). Moreover, it favors the purification of water from polluting substances (Beard, 1973), allows to capture a large part of the particulate matter in the atmosphere, and stores CO2 fixing it to the ground (Panella et al., 2006). Furthermore, like other plant formations, the turfgrass reduces the harmful threshold of noise and light intensity by absorbing the refraction of sound and light waves (Beard, 1973).

Ornamental, sporting, and recreational

 

This particular crop is established to provide places of interest with social and ornamental value. In many cases, turfgrass is a valuable element capable of enhancing the nearby elements. However, in other contexts, it must allow certain recreational or sports activities.

 

Therefore, turfgrass management is aimed at preserving those characteristics fulfilling its required functions. Currently, turfgrasses are used for many purposes and are managed in different ways according to the specific use.

 

Based on the functions and use for which they are intended, turfgrasses can be grouped into three main types (Beard, 1973): ornamental, sporting, and recreational.

 

Turf for ornamental use has high aesthetic value and is subjected to intense management; these turfgrasses are generally lightly trafficked. Their primary purpose is to create a pleasant environment to live and work in.

 

Sports turf includes grass surfaces used in various sports such as football, golf, tennis, polo, hockey, horse riding, etc. They represent the most specialized type and are subject to careful design and intensive management. They should satisfy aesthetic requirements other than specific sports and functional properties.

 

Turf for recreational use has poorer aesthetic value with an excellent ability to withstand wear. The management they are subjected to is less intense and always proportional to their degree of use; they are often located in parks and areas for sociocultural activities.

There are many cultural practices applied to turfgrasses, depending on their function and use.

 

Mowing is considered the most important practice because it affects the quality and persistence of the turf. The mowing frequency and height are decisive for maintaining the turf performance at a desired level (Schiavon et al., 2021). Generally, the lower the cutting height, the more the vegetation weakens; on the contrary, increasing the frequency reduces the plant’s physiological stress if subjected to occasional mowings (Fry and Huang, 2004).

 

Fertilizing and irrigation are also essential cultivation practices for turf. As a continuously growing crop, the turf needs constant nutrients, especially nitrogen. The quantity of water applied with irrigation varies significantly according to the species, type of soil, and climatic conditions. In addition to these main cultural practices, other complementary ones (coring, verticut, nailing, vertidrain, etc.) keep the turf in good condition when subjected to heavy traffic (Christians et al., 2019).

The aesthetic value represents a relevant element for each type of turfgrass. The aesthetic value depends on different parameters having equal importance: density, uniformity, colour, leaf texture, and the habitus of plant growth.Turfgrass with a high aesthetic value has fine texture, intense color, and excellent uniformity and density (Turgeon, 1980). For sports turf, the density is the most important parameter. In both cases, the turf quality is strongly influenced by the presence of diseases and/or weeds.

 

The turfgrass is a highly simplified herbaceous coenosis consisting of a few species, even just one, so it is particularly fragile. The choice of species and cultivars is essential for creating a long-lasting and sustainable turf, able to resist stresses, diseases, and weed invasion.

 

The traditional turf species belong to the Poaceae family (= Graminaceae) but can be replaced or mixed with other species. In the Poaceae family, species are distinguished into cool-season and warm-season grasses: cool-season ones prefer temperate or cold climates, while warm-season ones are typical of warmer climates, both arid and humid (Giolo et al., 2019).

 

The optimal growth temperature of warm-season grasses is between 25-26 and 35-36°C (Beard, 1973). In Mediterranean European countries, the most common are: Cynodon dactylon, Paspalum vaginatum, Zoysia spp. and Stenotaphrum secundatum.

 

The cool-season grasses growth activity with temperatures between 15 and 26 °C. The most commonly used turf species are Lolium perenne, Poa pratensis, Festuca arundinacea, Agrotis spp., and Festuca rubra. For these species, the optimal temperature ranges between 18 and 24 ° C. For this reason, their maximum growth occurs in spring and autumn, while in summer the growth is significantly reduced, and in winter it stops (Beard, 1973). The warm-season grasses are characterized by a C4 photosynthetic system more efficient at high temperatures and in water use compared to the C3 of the cool-season ones (Turgeon, 1980). The optimum growing temperatures of warm-season species are between 26 and 35°C, which are the typical temperatures of the summer months. When temperatures drop below 16 °C these species stop growing, and they turn yellow when temperatures are close to or below zero. Warm-season species are suitable for low-maintenance turfgrasses. They require, on average, 45% less water than cool-season ones, have greater resistance to wear, less susceptibility to fungal diseases, and use nitrogen more efficiently.

 

Their use in Italy is rapidly expanding due to changes in temperature and rainfall regimes consequent to climate changes. However, the long period of winter dormancy limits its spreading in northern Italy (Volterrani et al., 1997), an obstacle that can be overcome intercropping with cool-season species. Among these, the most common is the overseeding of Lolium perenne in a sports turf established with warm-season species.

References

 

– Argenti G., Seppoloni I., Franci M., Staglianò N., 2011. Evoluzione di inerbimenti in piste da sci in diversi contesti ambientali.

– Beard J.B., 1991. Guida per la costruzione e la manutenzione dei green nei campi da golf italiani. Federazione Italiana Golf.

– Beard J.B., 1973. Turfgrass: Science and Culture. Prentice Hall Inc., Englewood Cliffs, New Jersey, Usa.

– Cereti C.F., 1993. Il sistema colturale «tappeto erboso». Annali dell’Accademia di Agricoltura di Torino.

– Giolo, M., Benincasa, P., Anastasi, G., Macolino, S., & Onofri, A. (2019). Effects of sub-optimal temperatures on seed germination of three warm-season turfgrasses with perspectives of cultivation in transition zone. Agronomy, 9(8), 421.

– Christians, N. E., Patton, A. J., & Law, Q. D. (2016). Fundamentals of turfgrass management. John Wiley & Sons.

– Fry, J., & Huang, B. (2004). Applied turfgrass science and physiology.

– Schiavon, M., Macolino, S., & Pornaro, C. (2021). Response of twenty tall fescue (Schedonorus arundinaceus (Schreb.) Dumort.) cultivars to low mowing height. Agronomy, 11(5), 943.

– Panella, A., & Croce, P. (2006). Tappeti erbosi: cura, gestione, manutenzione delle aree verdi pubbliche e private. Edagricole.

– Turgeon A.J. 1980. Turfgrass Management.

– Volterrani M., Grossi N., Pardini G., Miele S., Gaetani M., Magni S., 1997. Warm season turfgrass adaptation in Italy – International Turfgrass Society Research Journal.