Irrigation is one of the most critical aspects of managing natural lawns, especially in high-traffic areas like football fields. The amount of water, timing (morning, afternoon, or evening), and frequency of irrigation all depend on factors such as grass species, soil type, and weather conditions. Proper lawn management requires a deep understanding of these variables, as well as the ability to assess current conditions and make informed decisions about watering. Unlike ornamental lawns in parks, football fields are subjected to intense use by players who run, jump, kick, and slide across the surface, which can lead to wear and tear, including matting and lifting of the turf. Therefore, it's generally recommended to irrigate less frequently but more deeply, ensuring that the grass has enough moisture without becoming waterlogged. During peak activity times, especially in hot seasons, careful irrigation becomes even more crucial.
In many school and practice football fields, the soil is often sandy, and sprinkler systems are commonly used. However, automatic sprinklers can sometimes overwater or operate too frequently, leading to inefficient water use and poor maintenance. This unscientific approach can cause early death, stunted growth, disease, and increased pest problems.
Soil moisture plays a vital role in plant health. When the soil dries to a certain point, plants cannot absorb the remaining water, and wilting begins. This level is called the wilting coefficient. On the other hand, when the soil is fully saturated, excess water drains away due to gravity, and the moisture content at this stage is known as field capacity. Effective water content refers to the amount of moisture available for root absorption, typically measured in millimeters per centimeter of soil depth. The range of water tension (PF) for effective water is between pF 2.5–2.7 (field capacity) and pF 3.9–4.2 (wilting coefficient). Different soil types have varying capacities within this range.
For example, in a sandy football field with a 20 cm soil depth, the effective water content ranges from 6.6 mm to 16.6 mm. The deeper the root system, the more water the plant can access. However, many factors—such as grass species, temperature, mowing height, and soil compaction—can influence how much water is needed and how often irrigation should occur. These factors must be carefully studied and tested before successful lawn management can be achieved.
Irrigation is closely tied to evaporation and evapotranspiration. Scientific methods are essential to gather accurate data. For cool-season lawns, daily evaporation is approximately 0.65–0.8 mm, while warm-season lawns may experience 0.55–0.65 mm. In temperate regions, evaporation rates can range from 2.5 to 7.5 mm per day. Based on this, irrigation intervals can be estimated. For instance, if the soil holds 15 mm of water and evaporates 5 mm per day, irrigation should occur every three days.
However, irrigation frequency isn’t solely determined by evaporation—it also depends on transpiration, temperature, and the efficiency of the irrigation method. Sandy soils, common in football fields, have low water retention, so improving the soil structure with organic matter, minerals, and soil conditioners can significantly increase the irrigation interval. This mixed soil approach can extend the time between irrigations by two to three times compared to pure sand.
There are several ways to determine irrigation intervals. Theoretical calculations and instrumentation, such as soil moisture sensors, are commonly used. Some methods rely on surface temperature measurements, though cooling the irrigation water may be necessary if temperatures become too high.
The amount of irrigation required for natural turf is critical for seedling development. While there’s no universal formula, comprehensive data—including grass species, soil quality, and weather conditions—are essential for making informed decisions. Combining scientific methods with practical experience is key to success. For example, in sandy soil, the available water at 15 cm depth is around 25.4 mm. For a 100 m² area, this equates to about 3 tons of water. A standard football field (over 7000 m²) would need roughly 210 tons. Exceeding this amount can be harmful to the plants.
Understanding the effective water content in different soil types helps guide irrigation practices. The table below provides an overview of field capacity, wilting coefficients, and effective water levels for various soil types:
| Soil Type | Field Capacity (%) | Wilting Coefficient (PF) | Effective Water (mm) |
|------------------|--------------------|---------------------------|-----------------------|
| Fine Sand | 0.5 | 3.5 | 3.0 |
| Micro Sandy Soil | 30.2 | 7.7 | 22.5 |
| Cohesive Soil | 30.5 | 17.5 | 13.0 |
Additionally, different grass species have varying water requirements. Cool-season grasses, such as fescue, ryegrass, and bentgrass, are more sensitive to heat and drought than warm-season varieties like zoysiagrass, bermudagrass, and carpetgrass. During hot periods, cool-season grasses may go dormant and benefit from misting to lower leaf temperature. In northern regions, this technique is particularly effective. Understanding these differences is essential for maintaining healthy, resilient turf.
Carpet Tile,Carpet Tiles,Bedroom Carpet Tiles,Carpet Tiles For Stairs
Changshu Keyuan Eco-friendly New Materials Co.,Ltd , https://www.ailiqingky.com