Building a Fertiliser Programme

April 16, 2020 · Sports Labs

When putting together the fertiliser plan for your sports pitch it is critical that you look at a number of factors to make sure you are applying the correct products at the correct time. Whether it is a local authority pitch built on heavy soil and exposed to the elements, or an elite level pitch inside a modern stadium equipped with undersoil heating, artificial lighting and a free draining sand based rootzone, it is essential that the correct products are applied at the appropriate time in order to maintain optimal plant health.

The key to building a successful fertiliser programme is understanding your site and conditions and knowing, not only when to apply fertiliser, but what is the appropriate product and what effect you are going to get. It is all well and good setting out a plan at the beginning of a year with projected products and application timings however it is down to the skill and local knowledge of the groundsperson to ensure that the yearly fertiliser plan is as fluid and adaptable as it needs to be to best suit the conditions. Remember that just because the fertiliser plan you wrote back in January says that you are due for an application tomorrow, doesn’t mean you must stick to this no matter what and very often, knowing when to do nothing is every bit as important as knowing when to do something.

What every turf manager is looking to achieve is adequate and sustainable growth and turf health throughout the growing season, whilst still maintaining enough nutrition in reserve to help accelerate that growth for recovery following times of stress to the plant such as intensive usage, adverse weather conditions and disease attacks. Nowadays, we very often hear talk of quantities of Nitrogen applied per hectare per year and there are any number of guidelines on what this should be. Whilst this is often very well thought through advice based on scientific research and data, we must not loose sight of the fact that this is very much a “horses for courses” situation and just because it works for the pitch up the road or indeed worked well for you last year, it doesn’t mean that we have found the system and plan that works for us and need not ever be adjusted.

The first step in building your fertiliser programme must always be to know what you already have and from there you can figure out what you need.

A full nutritional analysis of your rootzone is the critical first step in this process as this allows you to highlight any potential deficiencies and make a more informed decision on what you need to apply.

When testing a soil, pH is every bit as important as nutrient levels as this plays a huge role in the availability of the essential nutrients held within the soil.

In most soils and particularly where sustaining a sward dominated by Perennial Ryegrass, maintaining a soil pH of 6.5-7.5 will allow optimal availability for the majority of essential plant nutrients most notably, the big three – N, P & K.

Any fertiliser you use, whether granular or liquid will display a breakdown on the packaging focusing initially on the afore mentioned big three.

For example, a bag of granular fertiliser displaying 15.5.20 will contain 15% Nitrogen, 5% Phosphorous and 20% Potassium, whilst this is useful information in helping us keep track of inputs and quantities, to fully understand the effects of the product we must look in more detail at the nutrient derivation and therefore its availability and longevity within the soil.

Granular fertilisers can generally be broken down into three categories

·       Slow Release - The Nitrogen is generally more complex forms such as methylene Urea or organic sourced Nitrogen which is broken down and released for uptake by hydrolysis or microbial activity in a well aerated soil.

·       Controlled Release - These granules are often coated in compounds such as Polymer Sulphur which gradually breaks down and releases the nutrient in response to adequate temperatures and moisture availability.

·       Conventional Release - Often composed of basic Nitrogen compounds and a mixture of Ureic, Ammoniacal and Nitric Nitrogen. These granules are the most easily broken down and readily available to the plant.

When planning your annual granular fertiliser applications it is important that the merits of each type of granule is understood and properly utilised. The slow and controlled release products are often used as a “base feed” steadily delivering the nutrition over an extended period depending on prevailing conditions. Conventional release granules are more likely to deliver a flush of growth over a shorter period and are more commonly used to accelerate recovery, particularly those products predominantly ammoniacal or nitric Nitrogen.

Aside from granules, fertiliser can be efficiently applied to a sports field in liquid or foliar applications using a sprayer.

Let’s clarify from the outset, all foliar fertilisers are applied as a liquid but not all liquid fertilisers are applied as a foliar feed!!

A true foliar feed is a product that is applied in a low water volume and fine spray quality to minimise run-off and ensure that the product is applied directly to the leaf and not the soil. Foliar feeds are often formulated using adjuvant and surfactant additives to maximise the uptake potential of this product through the leaf. Foliar fertilisers deliver relatively small quantities of nutrition in each application however, if applied correctly, it is taken directly into the plant through the leaf with no potential for leaching or locking up in the soil. Liquid fertilisers can also be applied to the soil through a sprayer and whilst there may be a degree of foliar uptake, these are often far higher volumes of fertiliser and water and are often thought to be a good supplement to granular feeding and can be a very cost effective method if utilised correctly.

There are merits in applying fertiliser to a sports pitch in all forms. Budget and resources allowing, a good balance of all methods is the best approach and it is down to the knowledge and skill of the groundsperson to decide how and when to use each.