What are the requirements of the golf course?

Modern golf demands higher and higher lawn quality. The green speed of the US Open has reached over 65,438+00 feet. The increase of speed will inevitably require the mowing height of the green to hit a new low, from 5.0 mm in the past to about 3.5 mm now, further approaching 2.5 mm. Creeping bentgrass has become the first choice for golf course greens because of its excellent low pruning resistance, short creeping behavior, delicate texture, charming color and almost all-year green period. According to incomplete statistics, the application rate of creeping bentgrass on the greens of golf courses around the world is as high as 75%. The creeping bentgrass is a typical cool-season lawn grass, which is native to the temperate zone of northern Europe. Its optimum growth temperature is 15-20℃. When the temperature was higher than 25℃, the growth of creeping bentgrass was obviously inhibited. However, the summer temperature in most parts of China is much higher than 25℃. This year, the Yangtze River Basin experienced continuous high temperature weather of more than 25 days and above 35℃ in summer. Under such extreme environmental pressure, once the management is careless, the whole green will face the threat of death. Therefore, the over-summer management of creeping bentgrass greens is the most important technical obstacle in golf course management in China, and it is also the most headache for lawn managers. According to our latest research results, this paper analyzes the main measures and physiological mechanism of creeping bentgrass lawn management in summer, in order to help golf course lawn managers in China master the summer management technology correctly.

Firstly, the adaptive mechanism of creeping bentgrass to high temperature in summer.

Under the condition of high temperature stress, creeping bentgrass plants will produce corresponding adaptive mechanisms to reduce the damage caused by stress and obtain certain high temperature stress resistance. The heat resistance mechanism of plants includes heat resistance and heat avoidance. Plant heat tolerance is mainly manifested in membrane lipid composition and membrane stability, active oxygen and protective enzyme system, heat shock protein, dehydrated protein and so on. Some small molecular monitoring substances, such as rubber matrix and betaine, can also stabilize the spatial configuration and biofilm structure of functional proteins in cells under high temperature stress, and also participate in the regulation of plant heat tolerance to varying degrees.

The heat avoidance of plants is mainly realized by transpiration. Because of the transpiration or evaporation of plant water, the liquid water on the surface or inside the plant is transformed into gaseous water vapor, which takes away a lot of heat energy, which can reduce the surface temperature of leaves, improve the microenvironment of plant canopy and avoid the damage of high temperature.

The efficiency of plant transpiration mainly depends on the difference between the humidity of water vapor on the leaf surface and the humidity of the surrounding environment. The greater the humidity difference, the higher the transpiration efficiency, the greater the heat energy taken away, the lower the temperature of plant canopy, and the less the thermal damage to plants. This is also the reason why plants have poor heat resistance and are more vulnerable to heat damage under high temperature and high humidity conditions. Another main reason that affects the evapotranspiration efficiency of plants is wind. The higher the air velocity, the faster the water vapor diffusion rate, the higher the evaporation and transpiration efficiency, and the more obvious the cooling effect.

Second, some relationships in the heat resistance mechanism of creeping bentgrass plants

The relationship between photosynthesis and respiration.

Photosynthesis is the most important way for plants to use solar energy and store energy. The photosynthetic efficiency of each plant has a suitable maximum temperature limit, which is the saturation point of photosynthesis. When the temperature exceeds the saturation point, the photosynthesis of plants is obviously inhibited and the photosynthetic efficiency is obviously reduced. According to our research, the photosynthetic saturation point temperature of creeping bentgrass is about 28℃, and the photosynthetic saturation point of newly bred heat-resistant varieties (crenshaw, L-93 and Bin A-4) is about 2-3℃ higher than that of traditional heat-sensitive varieties (Bincross).

Contrary to photosynthesis, respiration is a process in which plants consume energy. With the increase of temperature, the respiratory function is also enhanced. When the energy consumed by respiration is greater than the energy synthesized by photosynthesis, plants will have energy deficit, which is often the initial factor for the decline of the quality of creeping bentgrass lawn in summer.

2. Relationship between daytime temperature and nighttime temperature

During the day, the temperature changes day and night with the rise and fall of the sun. Photosynthesis of plants can only be carried out when there is sunshine during the day, and respiration is inevitable 24 hours a day. In addition, the transportation and storage of plant photosynthetic products mainly occur at night. Our research shows that extreme high temperature during the day mainly causes direct damage such as disorder of photosynthetic electron transport chain, generation of oxygen free radicals, lipid oxidation of cell membrane and cell dysfunction. At night, plants can repair these direct injuries through their own regulatory mechanisms. If the heat damage during the day is not very serious and the temperature is low at night, plants can basically be completely restored in one night. However, once the temperature at night exceeds the tolerance range of plants, the self-repair ability of plants will be greatly reduced; On the other hand, the high temperature at night will greatly increase the respiratory consumption of creeping bentgrass, thus making the plant in an energy deficit state. In the long run, plants will fail and die because of energy exhaustion. Although the high temperature stress during the day and at night caused serious harm to creeping bentgrass, relatively speaking, the high temperature at night was more harmful. Usually, high temperature stress at night is the main reason for the quality decline of creeping bentgrass lawn. So the effect of cooling at night is far better than that in the morning.

3. The relationship between ground temperature and air temperature

Lawn managers usually pay attention to the growth of aerial parts of creeping bentgrass, but ignore the dynamic changes of underground roots. However, roots are much more sensitive to environmental high temperature stress than aboveground stems and leaves. Under the high temperature in summer, the root growth of creeping bentgrass was first inhibited, which showed that the root system shrank, its vitality decreased or even became extinct. Our research shows that under high temperature stress, the ability of root system to synthesize cytokinin decreases rapidly, and the signal of root system to transport cytokinin to aboveground parts weakens, thus inducing peroxidation in plants, destroying the protective enzyme system in plants, causing membrane lipid oxidation and leakage, chlorophyll degradation and yellowing, and finally leading to serious decline in lawn quality and even death. Comparatively speaking, the harm of extreme ground temperature is much more serious than that of extreme temperature. Reducing the environmental temperature of roots can significantly reduce the high temperature damage of lawns and maintain high quality lawns.

Third, the management measures of creeping bentgrass over summer

1. Select a creeping bentgrass variety with strong heat resistance.

Although creeping bentgrass is a typical cool-season grass species, its tolerance to extreme high temperature in summer will be limited to some extent. However, through the continuous efforts of lawn breeders in recent years, some new varieties, such as crenshaw, L-93, Bin A-4, SR- 1020, have significantly improved their heat resistance. At present, Bing A-4 is the most widely used golf course in China, but little is known about the specific performance of other varieties in the local area. It is necessary to establish a lawn evaluation system similar to NTEP in the United States, so as to provide reliable basis for the correct selection of golf course lawn varieties in various regions of China. In addition, I hope that lawn managers will remember that choosing the right lawn variety is only the first step, and it can't solve all the problems in summer management of creeping bentgrass greens. You still need to spend a lot of energy to improve the growth environment of the green, improve the performance of the lawn, and take careful maintenance and management measures to ensure the normal sports quality of the green in summer.

2. Increase the air mobility of the green.

Wind can help to form and maintain a good humidity gradient between plant leaves and air, thus increasing the transpiration rate of plant stomata, reducing the temperature of lawn canopy and avoiding plant heat damage. Measures to increase air flow should be considered in golf course design: the green should be chosen in an open place with high terrain to avoid low-lying basins surrounded by mountains; When distributing trees around the green space, the location of local summer wind direction should be considered to ensure good ventilation of the green space. On the green land that has been built in unfavorable terrain, the most common and last resort method abroad is to install artificial wind power devices such as electric fans in the vegetation around the green land, but this method will not only increase the management cost, but also cause disharmony with the environment.

3. Establish and maintain a good green lawn structure.

The healthy growth of creeping bentgrass needs good ventilation, water coordination and fertile root soil structure. Poor drainage and soil hardening are the most common reasons for the decline of golf course greens. The soil aggregate structure in most parts of China can not meet the requirements of green, and the soil in some areas is too sticky and easy to harden; In some areas, the soil salt content is too high; However, the pH value of soil in some parts of the south is too low, so it is necessary to improve the soil according to local conditions when building green. At present, the green building structure of golf courses in China follows the recommended standards of the United States Golf Association (USGA), but there is still a big gap in the control and control of the composition ratio and physical and chemical properties of the root soil layer, and sometimes there is even a lack of monitoring and control of the structural stability of the soil layer, the water infiltration rate, the ion exchange capacity of soil particles, and the adsorption capacity of soil to major nutrients. The problems left over from the construction of these greens directly affect the quality of the greens and their ability to cross the summer. We often see the phenomenon of soil hardening. In summer, the lawn in poor drainage area first appears the phenomenon of density decline, yellowing and losing green. Our research shows that the viscosity and poor drainage of soil will seriously affect the healthy growth of stolon roots. Roots grown under waterlogging conditions are extremely sensitive to heat stress, and their decline rate is much higher than that of well-ventilated soil roots.

In addition, soil viscosity and poor drainage are conducive to the occurrence and infection of brown spot, Fusarium wilt and pythium. Although these diseases can be prevented by frequent use of fungicides, serious symptoms of these diseases will appear every year before the soil structure is obviously improved because the soil conditions are conducive to the reproduction and infection of these bacteria.

4. Foliar spray cooling

Under the condition of high temperature stress, the water absorption capacity of plant roots decreases, while the transpiration rate increases, and plants will be short of water. In order to prevent excessive water loss in the body, plants will automatically close their stomata to reduce water transpiration. In this case, the transpiration cooling regulation function of the plant itself fails. In management, foliar spraying is usually used to increase the heat taken away by leaf water evaporation, thus reducing the temperature of lawn canopy and avoiding heat damage.

But foliar spraying is not irrigation, but only to moisten the leaves of plants, increase water evaporation and cool down. When spraying leaves, you should pay attention to spraying different areas of green separately. More water can be sprayed in areas with high terrain and severe drought, and less or even no water can be sprayed in areas with low water accumulation. Therefore, foliar spraying is usually operated manually by experienced workers.

The common mistake of foliar spraying is to spray too much water, especially in low-lying hay layer. Because stagnant water can gather the radiant energy of the sun and raise the water temperature, it will cause the roots of the lawn to be soaked in hot water, and the roots will soon burn and die.

5. Raise the pruning height appropriately.

Creeping bentgrass is a process of consuming stored energy in summer, so increasing the stored energy in plants can effectively improve the ability of creeping bentgrass to cross summer. Before the arrival of high temperature in summer, the photosynthetic area and photosynthetic efficiency of creeping bentgrass should be appropriately increased within the allowable range to store more photosynthetic products and reduce the energy deficit of lawn in summer. Our research shows that only by increasing the lawn mowing height from 3.3 mm to 3.4 mm can the lawn quality be significantly improved in summer; In addition, increasing the leaf area of aboveground parts is beneficial to slow down the decline process of underground roots.

6. Correct fertilization

Fertilization is a misunderstanding in the management of creeping bentgrass in summer. Many lawn managers accept the view that excessive nitrogen fertilizer can easily make lawn plants grow white, make tissues tender and reduce the resistance to high temperature. Therefore, the greens are generally not fertilized all summer. This view is absolutely correct, but they ignore another aspect: insufficient nutrients will also reduce the lawn's resistance to heat damage and greatly reduce the lawn's ability to repair damage. Therefore, in the summer management of creeping bentgrass greens, the amount of nitrogen fertilizer should be cautious: it should not be too much, which will lead to excessive growth and consume too much energy stored in plants; But it should not be lacking, leading to malnutrition. Under normal circumstances, it should be possible to fertilize according to grass conditions. When the growth potential of the lawn is insufficient and it is obviously yellow, a small amount of nitrogen fertilizer should be applied topdressing, and the amount is small, mainly quick-acting fertilizer.

For phosphorus and potassium fertilizer, it is helpful to plant resistance. Before the arrival of high temperature in summer, it is best to apply sufficient phosphorus and potassium fertilizer to ensure that plants are in a robust state to resist high temperature adversity. In addition, a small amount of trace element iron can be added to increase the stability of chlorophyll.

7. Correct use of plant growth regulators

Plant growth regulators can effectively regulate the growth ratio of aboveground parts and roots of plants, regulate the transportation and distribution of nutrients in plants, and control the opening and closing of stomata in plants. According to our research results, cytokinin is the main signal substance for the regulation of heat resistance of creeping bentgrass, and the main reason for the decline of heat resistance of plants is the weakening of synthesis and conduction of cytokinin signal in roots. Supplementing exogenous cytokinin to roots can antagonize the adverse physiological process caused by heat stress and improve the ability of plants to resist high temperature stress. In addition, some auxins and growth retardants can improve the accumulation of plant nutrients, and measures to promote nutrient accumulation and root growth in plants are helpful to improve the over-summer ability of creeping bentgrass lawn.

To sum up, in order to maintain the high sports quality of creeping bentgrass lawn in hot summer, we must fully understand its heat-resistant mechanism, and on this basis, take correct management measures, focus on improving the growth environment of green lawn, and incorporate the over-summer management measures into the long-term management plan for the whole year or even five to ten years, so as to fundamentally solve the possible over-summer problems of lawn.

About the author:

Wang Zhaolong, Director and Professor of Grass Industry Center, School of Agriculture and Biology, Shanghai Jiaotong University. 1999-2002: Visiting scholar and postdoctoral researcher at Cornell University School of Agriculture and Life Sciences and Rutgers University Lawn Science Center respectively. His research direction is the physiological mechanism of drought and heat resistance, breeding improvement and management norms of golf greens. From March, 2002 to June+February, 5438, he was the weekend director of Royce Brook Golf Course in the United States, and was responsible for the over-summer management of L-93 creeping bentgrass green.

) the location of the golf course

Golf courses are generally located on open gentle slopes in hilly areas, covering an area of 65~75 hectares, depending on the number of holes. Specific site selection requirements are as follows: 1, terrain requirements. The land used in the base should not be too rugged or steep, and some natural features such as gentle slope and water surface can be reserved in the base as the natural barrier of the stadium. The fairways and greens of golf courses need to be planted with high-quality turf, so it is very important to analyze and treat the soil. Sandy soil is an ideal soil for golf courses. Whether the nutrients in the soil have been exhausted by the original crops and whether it can meet the needs of planting turf, these factors should be considered in detail when selecting the site, which is conducive to future maintenance and management. 3. Convenient transportation. Golf courses should have convenient traffic conditions, and are generally chosen near expressway or the main roads of the city. Large area lawn maintenance of golf course needs a lot of water, and sufficient water supply is an important factor affecting golf course maintenance. 5. The environment is elegant. Golf courses should choose areas with elegant environment and pleasant climate, such as lakes, forests, scenic spots and hillsides.

(2) Golf courses mainly constitute golf courses.

Yin includes a clubhouse, a standard court, a driving range and some ancillary facilities. The main specifications of the course are 9 holes and 18 holes, which need to be determined according to the requirements of the venue and the club. Regular 18 hole courses are divided into 18 courses with different sizes and shapes, and each course consists of tees, fairways, greens and holes. The total length of the standard stadium is 5943 ~ 6400 m, and its width is uncertain. There should be boundaries around the stadium, and boundary markers should be set in key areas. 1, lobby. Also known as golf clubs, most of them are located at the entrance of golf courses, providing places for players to rest, change clothes and eat. There is a parking lot in front of the clubhouse, and there are usually scenic spots for players to climb up and overlook. 2. Three links. The tee is the starting point of each fairway. A fairway often includes three teeing areas with different distances, namely, the female teeing area (20% closer to the green than the male teeing area), the male teeing area and the competition teeing area (farthest from the green after the teeing area). Sometimes, three tees are combined into one big tee. The service area should be higher than the surrounding terrain to facilitate drainage in rainy days. 3. fairway. Fairway is the largest part of the course, which is the section from the service area to the green. There are undulating terrain or trees on both sides of the fairway, which separates the fairway from the fairway. The fairway is a wide lawn, and players can generally see the green in the service area. According to the player's hitting distance, bunkers, ponds, streams and other obstacles are often arranged around the landing area and the green in a planned way to punish the player's hitting mistakes and improve the excitement and intensity of the game. 4. green. The green is the core of each fairway and the location of the hole. After the ball is hit into the fairway, it will enter the next fairway. The green covers an area of11~ 2,545 square meters, is circular and oval in shape, and its height is 30- 100 cm higher than the surrounding terrain. 5. Driving range. Driving range is a place where beginners learn to play ball. It can be located near a city or a golf course.

(3) Key points of stadium design

The design of golf course has certain flexibility, which is different from other sports venues. There is no fixed and strict scale requirement, as long as the number of strokes per hole and the fairway length are basically met. Golf courses are generally selected in areas with natural terrain. Therefore, an important principle of design is to adjust measures to local conditions, skillfully use the original terrain for on-site planning and design, make full use of the original natural landscapes such as tombs, mountains, lakes and woodlands, and combine the competition requirements of Gaoer Stadium to minimize the amount of earthwork and carry out comprehensive planning and design. This not only saves investment, but also easily forms its own characteristics. Pursuing individuality is a major feature of golf course design. There are no two identical golf courses in the world. In order to attract more members, each golf course department has conducted in-depth research on the creation of its own characteristics.

1, tee setting: Tees have various shapes, such as rectangle, square and ellipse. In addition, semicircle, circle, S-shape and L-shape are also commonly used. —The general area is 30—150m2, which is 0.3 ~ 1.0m higher than the surrounding area to facilitate drainage and increase the visibility of the batter. The surface is trimmed short grass, which requires the lawn to have a certain hardness and a smooth surface. Although the tee area is small, the track is heavy, which requires the surface water to be quickly removed, and it should have a certain flatness from the service point of view, generally taking a slight slope of L%-2%.

2. Fairway design: the north-south direction is the ideal fairway direction, and the fairway is generally 90-550 meters long; The width varies from 30 meters to 55 meters, and the average width is about 4 1 meter.

3, green space design A. Green space is the key area of Goyle Stadium. The size, shape, outline and surrounding bunkers of each green have their own characteristics, creating rich challenges and fun. The height of the green lawn should be 5.0-6.4 cm, and it should be flat and smooth. B. Green drainage. Surface water on the green should be discharged from two or more directions. The terrain design of the green should make the drainage line of surface water avoid the direction of people flow. Most slopes of the green should not exceed 3% to ensure the direction of the ball after hitting the ball. Practice green. The practice green is a special practice place for golfers to practice hitting the ball into the hole. The practice green is usually located near the golf club and the first tee. It shall be possible to set 9- 18 holes and their replacement positions. The surface of the green should have a certain slope. 3% is also appropriate. In order to ensure the quality of practice greens, a golf course should be equipped with two or more practice greens for rotation.

4. Obstacle area: Obstacle area is generally composed of bunkers, pools and trees, in order to punish athletes for not hitting the ball correctly. It is much more difficult to hit the ball out of the obstacle course than to hit it into the fairway. A. bunker The general area of bunkers is 140 ~ 380 square meters, and some bunkers can be as high as 2400 square meters. At present, most golf courses with 18 holes have 40-80 bunkers, which can be determined according to the needs of playing and the designer's design ideas. The bunker setting on the court should conform to the natural strategy, so that players can think of the correct position of the tee. Usually, the position of fairway bunker is determined by the distance of tee-off in the championship. The location of the bunker should be determined according to the drainage characteristics of the site. Coal bunker should have good above-ground and underground drainage conditions. In areas with low terrain, sufficient underground drainage or good seepage conditions under the bunker, the bunker can be built below the grass surface. From the perspective of maintenance and management, the bunker on one side of the green should be set at a distance of 3-3.7 meters from the green lawn to facilitate the passage of construction machinery and prevent the sand in the bunker from being blown to the lawn by the wind. The sand in the green grass-roots bunker. The sand thickness of fairway bunker is relatively shallow. The requirements for sand used in the bunker of Gower Stadium are strict, and more than 75% of the sand has a particle size of 0.25-0.5mm (medium sand). It is best to choose angular sand for sand. The color of sand should be white, brown or light gray. But it is necessary to avoid that the sand is too white to see the sphere clearly. Swimming pool. The pool is not only an obstacle to hitting the ball, but also plays a very good beautification role. The swimming pool can be designed in a single fairway or shared by several fairways 1 swimming pool. Sometimes, the table or green is located on an island surrounded by water, which increases the difficulty and fun of hitting the ball and enriches the fairway landscape. Poolside is suitable for beautifying the environment. You can build a small bridge and a pavilion. When the area is large and the water source is sufficient, a fountain or waterfall can be planned.

5. logo tree. The sign tree in the golf course is planted to enable the golfer to calculate the location of the ball when hitting the ball. It is often planted at a distance of 50, 100, 150, 200 yards (1 yard =0.9 144 meters) from the tee, and can be planted at 50 and 65438 positions.

6. Others. In addition to the above aspects, golf course design generally includes driving range, clubhouse and rest pavilion, which can be set flexibly according to specific conditions. In terms of court area, 18 fairway is planned from dozens of hectares of land. The average 18 hole course consists of 4 short holes, 4 long holes and 10 middle holes, with a par of 72. However, if there are differences between topography and land area, par can be between 72 and 3. In other words, the par of 18 hole is acceptable between 69 and 75. Under the designer who is good at planning, the function of the whole stadium 18 hole can make full use of the whole 14 club group.

The distances of other short, medium and long holes are specified as follows:

Short hole par 3, length less than 250 yards.

Middle hole -Par4, the length is between 25 1 and 470 yards.

Long hole-par five (par five), with a length of

It may be a little long. If you really like golf, I hope you won't feel bored.