0 Plant Nutrition - Food for Thought

During World War II the need for air support to troops on the ground was vitally important, particularly in the pacific region. Landing zones were extremely difficult as the natural environment was wooded scrubland.

Clearance of such sites was made and, following this clearance, re-growth management undertaken by applying Anhydrous (water free) ammonia. This helped to ensure extremely hard runways.

Nearly seventy years on these landing sites can still be seen from miles above our planet as re-growth has not occurred due to the ammonia, the basis of our present day fertilisers. For example, ammonia nitrate is produced by combining anhydrous ammonia and nitric acid. Urea is produced by combining anhydrous ammonia with phosphoric acid.

In 1903 Cominco Ltd constructed an anhydrous ammonia plant at Trail, British Columbia, and became the first producer of granular fertiliser in 1932. The company produced a granular ammonium in 1963, followed by a granular urea in 1964.

So, is it not conceivable that, if we continued to apply such ammonia based salt fertilisers, our soils will become more compacted and toxic and less likely to sustain plant growth? This could result in restricted root room, exchange and nutrition pick up, along with poor drainage and, therefore, the need for yet more fertiliser applications to compensate for the decline. A spiral effect that leads to greater decline and, importantly, budget implications.

A non organic turf manager tends to rely on these kinds of fertilisers to achieve their needs, but there are always downsides. It is all about 'balance'. You will inevitably feed more and apply more fungicides to control disease, whilst not necessarily achieving more. You will apply chemical growth retarders to manage the unruly growth habits which have arisen from the salts, otherwise fuel costs will escalate, i.e. more mowing on a daily basis.

Over-use of salt based fertilisers tends to stimulate retardation in Poa annua, particularly in early spring growth. How many greenkeepers observe that their greens are not responding to growth at such times, for example, that spring growth is poor? It appears more common than ever this year following two poor summers and very cold winter and spring period.

The developments in environmentally friendly and natural products have been evaluated by greenstaff and managers in recent years. The unique combination of nutrients that contribute to a greener, stronger, healthier and sustainable turf is possible.

The supply of stabilised amine nitrogen, in a form that is highly accessible via both the foliage and the roots, is now available. Calcium is bonded to develop stronger soils. Aeration and water penetration are improved and salt accumulation lessened.

Magnesium and iron are constituents of chlorophyll, which is produced by the grass to give its green colour. Both of these elements are formulated, thereby making complex forms available for rapid assimilation via the foliage, which then remains accessible in the soil for take up by the roots. These types of products will replace at least 50% of nitrogen application on all turf and lawns where good colour, sward density and health are desired.

Feeding within this regime does not encourage excessive vegetation growth. However, other salt based nitrogen applications should be reduced to allow for the replacement of the nitrogen by these new products, otherwise the total nitrogen may encourage excessive vegetative growth.

What once we considered best management has now given way to a whole new suit of better practices, which cultivate environmental responsibility and better green and grass management.

Technology offers more opportunities than ever to improve returns on investment. But, even sports facilities utilising 21st century genetic technologies, will not reach their full plant potential with 20th century fertilisation programmes and chemistry.

Ideas about good fertilisation are changing, and for the better. Each growing season brings conditioners that challenge the turf manager and the facilities in different ways. Understanding, and becoming familiar with, the language of the plant will help you meet these challenges. The adage is "If you always do what you always did, then you will always get what you always got."

You may say, "I've used the same fertilisation programme for years, why should I change now?" Well, there is a much better understanding now of how plants use nutrients. Applying this knowledge can give you better quality greens and grass.

Today, the goal of a "best management" fertilisation programme is to feed the plant not the soil. The correct amount of nutrients should be available to the plant as it needs them in various stages of growth. This may mean more applications at lower rates of nutrients throughout the growing season.
The question now is, are equal amounts of each nutrient needed to sustain growth? The answer is no!

The nutritional needs of each grass are different. Therefore, each element must be present in sufficient quantity for the others to work to their potential. Just a small, economical foliar application may be enough to provide the critical quantity of a particular nutrient which is essential for the optimum growth. These would include Baron (B), Copper (Cu), Iron (Fe), Molybdenum (Mo), Zinc (Zn), Manganese (Mn), Colbalt (Co), Nickel (N) and, most recently, Chloride (Cl).

A balance of all nutrients must be achieved in the leaf because this is where the plant gets photosynthates which are its food. They are transferred out of the leaves to the plant's growing points (foliage roots, fruits or nodes) as needed in various stages of its growth. It is critical to feed the plant, not just the soil.

With all the required nutrients in place, many of them chelated, the plant can then select the nutrients it needs at any stage of growth. This is called "free choice feeding" and it enables the plant to grow naturally to its full potential.

But, I hear you say, "my budget's not growing, so how much will this balanced nutritional programme presenting this 'free choice feeding' cost?"

The good thing is that it will cost you no more than you are already spending on your fertilisation programme. Often, it is simply a matter of reallocating you current fertiliser expenses to make them more efficient through the use of secondary and micro nutrients. In addition, these can be tank mixed so they are applied at the same time as other liquid formulations, e.g. seaweed extracts and forms of liquid derivatives, thereby ensuring that adequate levels of nutrients are present. This can make significant differences in your sward/grass and its quality. Which translates into improved return for you.
Alternatively, continue to put chemicals on your turf and continue to decline. The choice is always yours!!

Contact David H. Bates on email at DHBatesservices@aol.com

Editorial Enquiries Editorial Enquiries

Contact Kerry Haywood

07973 394037

Subscribe to the Pitchcare Magazine Subscribe to the Pitchcare Magazine

You can have each and every copy of the Pitchcare magazine delivered direct to your door for just £30 a year.