As greenkeepers we strive for the perfect bowling green, so understanding the underlying science of plant health is paramount. One often overlooked but critically important element in fine turf management is Silicon (Si). Despite being the second most abundant element in the Earth’s crust, Silicon’s role in plant health, particularly in turfgrass, is only now being fully appreciated. This article explores the significant benefits of Silicon in turf management, the paradox of its scarcity in plant-available forms, and how modern products like PotSi, can help greenkeepers maintain healthier, more resilient turf.
The Importance of Silicon in Plant/Turf Health
Silicon’s Role in Cell Wall Resilience
Research has shown that Silicon plays a crucial role in strengthening cell walls, which is vital for turfgrass resilience against various biotic stresses like insect pests (leatherjackets and chafers) and fungal diseases. Silicon is deposited as amorphous silica within the cell walls, increasing their rigidity and making it more difficult for pathogens to penetrate. For instance, studies have demonstrated that Silicon-treated plants show reduced susceptibility to fungal infections such as Dollar Spot and Fusarium, which are increasingly common problems in fine turf.
Xylem and Phloem Structure Enhancement
Silicon also contributes significantly to the structure and function of xylem and phloem tissues in plants. The xylem and phloem are essential for the transport of water, nutrients, and photosynthates throughout the plant. Silicon fortifies these tissues, enhancing the plant’s overall structural integrity and water-use efficiency. This is particularly beneficial in turfgrass, where consistent moisture management is crucial for maintaining turf quality .
Impact on Leaf Erectness and Photosynthesis Efficiency
One of the less obvious but equally important benefits of Silicon in turfgrass is its influence on leaf erectness. Silicon accumulation in leaf tissues promotes more upright growth, which enhances light interception and, consequently, photosynthesis efficiency. This is particularly important in fine turf grass species that are typically subjected to close mowing, leaving minimal photosynthetic tissue to do the work of food production for the plant. Optimal photosynthesis can lead to denser, healthier swards, which are better able to outcompete weeds and recover from wear.
Silicon’s Influence on the Availability of Other Key Nutrients
Interaction with Calcium and Boron
Silicon does not act in isolation; it interacts with other essential nutrients such as Calcium (Ca) and Boron (B), which are critical for cell wall stability and membrane integrity. Silicon enhances the availability and uptake of Calcium, which is necessary for the formation of Calcium pectates that strengthen cell walls. Similarly, Silicon’s interaction with Boron helps improve the structural integrity of cell walls and reproductive tissues. The synergistic effect of Silicon with these nutrients can significantly improve turfgrass resilience to both biotic and abiotic stress factors .
Benefits of Silicon in Mitigating Stress Factors
Biotic Stress Resistance
Silicon has been shown to confer resistance to various biotic stresses, including fungal diseases like Dollar Spot and Fusarium. Silicon fortifies plant tissues, making it harder for pathogens to invade. Furthermore, when applied in immediately plant usable form, Silicon can trigger systemic acquired resistance (SAR) in plants, a defence mechanism that helps prevent disease outbreaks.
The strengthening effect of silicon on cell walls, makes plants less susceptible to damage from root herbivores like Leatherjackets and Chafers
Abiotic Stress Tolerance
Beyond biotic factors, Silicon also enhances plant tolerance to abiotic stresses such as drought, salinity, and extreme temperatures. In high-stress environments, Silicon helps maintain water balance, reduces oxidative stress by scavenging reactive oxygen species (ROS), and stabilises chloroplast membranes, which are crucial for photosynthesis under suboptimal conditions .
The Silicon Conundrum: Abundance vs. Availability
Despite Silicon’s abundance in the Earth’s crust, the plant-available form, silicic acid, is often lacking in highly managed soils. This paradox can be attributed to several factors:
Pesticides and High-Salt Fertilisers
The use of certain pesticides and high-salt synthetic fertilisers can negatively impact soil microbial communities, particularly those involved in Silicon solubilisation. These microbes are essential for converting the abundant Silicon in the soil into silicic acid, the form that plants can absorb. The depletion of these microbial populations reduces the availability of Silicon, even in soils rich in raw materials like sand.
High Sand Content Soils
In highly managed turf systems, especially on sand-based greens, the challenge of Silicon availability is exacerbated. Although sand contains ample Silicon, it is primarily in a non-available form. The lack of organic matter and microbial activity in these soils further limits the conversion of Silicon into plant-usable forms .
PotSi: A Solution for Modern Turf Management
Given the critical role of Silicon and the challenges associated with its availability, greenkeepers can turn to materials like PotSi, which provides Silicon in a form that is readily available for plant uptake, ensuring that your turf receives the Silicon it needs to build strong cell walls, enhance nutrient uptake, and resist both biotic and abiotic stresses.
Timely applications of PotSi have been shown to be particularly effective in preventing the onset of fungal diseases. For example, applying PotSi at the early stages of a Dollar Spot outbreak can significantly reduce disease severity by fortifying the turfgrass against the pathogen. This proactive approach not only mitigates disease impact but also reduces the need for chemical fungicides, promoting a more sustainable turf management strategy .
Applying Potsi at the early signs of a Dollar Spot attack can reduce the severity of the outbreak and minimise damage to plants.
How to get started
Silicon is an indispensable element in fine turf management, offering a range of benefits from strengthening plant cell walls to improving nutrient uptake and enhancing stress resistance. Despite its abundance in the soil, plant-available Silicon is often lacking in managed turf systems, making it essential for greenkeepers to consider supplemental applications. PotSi, with its readily available form of Silicon, provides a practical and effective solution to this challenge, helping to maintain healthy, resilient turf.
- To increase the plant available silicon in your soil apply 750mls of Potsi in 50-75 litres of water at 6 weekly intervals throughout the year.
- Additionally, Potsi can be applied at the first signs of a disease outbreak to bolster plant defences to help minimise the spread and effect of any fungal disease outbreak.
