Silicon is the second most abundant element present in the Earth’s crust. The Earth’s crust is where many plants and their roots evolved over millions of years, obtaining the minerals essential to complete their life cycle. When you think about it, it makes sense that silicon would be essential for plants, but this is not the case. Silicon is not listed as one of the 17 essential elements for plant growth. It is, however, considered “quasi-essential” because certain plants cannot complete their lifecycles without it. So if silicon isn’t essential to your lawn, then why would you bother applying it in the first place? In this blog, we’ll discuss why you should or shouldn’t spend the money to apply silicon to your lawn.
What does the research say?
The short answer is that, yes, there could be some benefits to applying silicon to your lawn. But the questions of just what those benefits are and how much silicon you need to apply to realize the benefits are up for debate. Also, will the cost of the product be worth any benefits that you are likely to see? Let’s take a look at some of the claims about silicon:
- Reduced Disease Occurrence
- Increased Traffic Tolerance
- Reduced Drought Stress and Salinity Stress
Reduced Disease Occurrence
Applications of silicon have been documented to reduce gray leaf spot, dollar spot, and brown patch in St. Augustinegrass, ryegrass, and bermudagrass. The problem with what has been discovered is that the rates of silicon that are necessary to apply to see disease reduction are off the charts. There is also a high degree of variability in response, and sometimes the disease was reduced but was not reduced to an acceptable amount that wouldn’t require fungicide applications. There is a lack of research investigating these effects in various soil types, as most research has been conducted in a specific type of soil. It is thought, however, that foliar applications may cause changes to the leaf surface which could reduce disease occurrence.
It seems as though the idea that silicon will increase traffic tolerance is due to the thought that silicon fertilization will result in a stiffer, more rigid leaf blade. This theoretically should increase the plant's resilience to foot traffic. There have been studies demonstrating some sort of increased wear tolerance from silicon fertilization, but again, grasses, rates of silicon applied, method of application, and soil type all create great variability in response.
Reduced Drought Stress and Salinity Stress
There have been studies showing improved growth of St. Augustinegrass and Kentucky bluegrass under extreme drought stress from silicon fertilization. Silicon fertilization has also been shown to reduce sodium absorption by Kentucky bluegrass roots. But again, we run into the same problem of high variability and large rates of silicon necessary.
Well, Should You Apply It?
That answer mostly depends on your budget. Repeat applications or summer season-long applications are probably warranted if you’re expecting to see results from silicon fertilization. It does not appear that silicon applications will increase disease occurrence, reduce traffic tolerance, or reduce drought tolerance, so a silicon application will never hurt you. It’s worth a try, and if you don’t see any benefit, then down the road, you can cease the applications altogether. Guertal and Datnoff (2021) provide a great review of all things silicon in this paper. If you’re good with sticking to the tried and true fertilizer ingredients, contact us today for a free lawn care plan.
Guertal, E. A., & Datnoff, L. E. (2021). Silicon in turfgrass: A review. Crop Science, 61(6), 3861-3876.