The level of photosynthetic flux emitted by the artificial lighting system directly influences plant growth. The greater the amount of energy captured and accumulated, the greater and better the growth. However, there is a limit to the rate of energy that can be absorbed by plants, after which they enter saturation, no longer absorbing more energy and, worse still, spending additional resources in the process. In extreme situations, plants can enter a process of degradation due to oxidation of the chlorophylls.

Clearly identifying the applicable saturation levels is therefore fundamental to finding the best compromise between growth and profitability. These limits vary from plant to plant.

The amount of energy accumulated by plants over a 24-hour period (photobiological rhythm) dictates the conditions for their growth and development. The higher its value, the greater the amount of energy available for all the necessary photobiological processes, and therefore the greater and better their growth. However, there are limits beyond which plants will activate rejection mechanisms, consuming precious resources in addition to the resulting energy waste. On the other hand, if the level of accumulated energy is not sufficient, the plants will not be able to develop properly.

The daily energy levels required vary from plant to plant and are strongly dependent on environmental factors such as temperature and humidity. Clearly identifying these levels is fundamental to finding the best compromise between growth and profitability.

The spectral quality of a light source is one of the fundamental factors in the plant growth process, an indicator of how the emitted energy is distributed in the photosynthetic active region (PAR). The more complete the spectrum, the better for plants to be able to carry out the different tasks required, but the worse for the efficiency of the process. In fact, since not all plants have the same requirements, the more the emitted spectrum is adjusted to the absorption curve of the applicable type and growth stage, the greater this efficiency will be, reducing costs and environmental impact. The combination of quantity and quality factors dictates the effective value of the lighting solution provided.

In the case of natural lawns, the photosynthetic process is central to their growth, since this is limited to the vegetative phase. There are other secondary processes involved, albeit with much lower energy requirements. Lighting systems should be designed to maximise the energy captured in the photosynthetic absorption regions. More than that, they must ensure the right spectral ratio to meet the requirements of a high-performance lawn, particularly in terms of rooting, plant density, leaf density, stem height and colour.

In the case of natural lawns, the photoperiod varies greatly depending on the type of plant used. Plants that have developed naturally at higher latitudes are prepared to work with less sun exposure and therefore shorter photoperiods. On the other hand, plants from more southerly regions (northern hemisphere) are used to longer photoperiods. Given the great adaptability of these plants, the number of hours of exposure is actually quite flexible and wide-ranging, allowing for enormous versatility in the use of artificial lighting systems.

Despite this, it is necessary to respect a maximum number of hours of exposure to artificial lighting, so that the plants can carry out the different tasks that are essential for their growth and that only take place at night, i.e. during the almost total, or even total, absence of light. If this rest period is not respected, the plants will struggle and this will lead to their degradation and, ultimately, death.

The photoperiod depends on the photosynthetic flux density and the DLI, since once the daily energy objectives have been reached, the artificial lighting system can be switched off, reducing energy and environmental costs. It is necessary to study and identify the most suitable photoperiod value, which varies from plant to plant.

Controlling the photobiological rhythm of plants is fundamental to regulating their internal functioning. This rhythm is naturally imposed by the length of the solar day, more specifically by the sequence of day and night. It is essential to control this rhythm, respecting the planned photoperiod, otherwise the plants will struggle, degrade and ultimately die.

In the case of natural lawns, this situation is no exception, leading to the weakening of the plants' roots, leaves and stems in stressful situations.