Imagine that you are at a festival in a foreign country and a beautiful street performer is addressing a crowd of enthralled visitors. In front of her, she has several vials containing various elements and several loaves of bread. She is regaling her audience in the art of alchemy and how she can make bread from the elements in the vials before her. What are you thinking? Seriously, what are you thinking? I’m thinking that this young lady, while attractive, is full of horse feathers! However, if we ponder this proposition for a moment, and if the carnival lasted for several months, grain. This may or may not reflect our N fertility program or merely the amount of N that ended up in the grain. The more N we have stored in the grain, the higher the protein content.
But protein is a function of multiple elements and serious agronomic management. If any element becomes limiting in the plant, then yield and protein are compromised. Thus, we need to consider the relative amounts of each element that is required, when in a crops life they are most needed, their forms of availability, the balance (ratio) of those elements for optimal production and the impacts of biotic and especially abiotic stress.
Let’s briefly consider the amount she would pull this magical feat off easily!
What does the ancient art of alchemy — the art of turning base metals into gold and silver have to do with agronomy? Well farmers, are really the first true alchemists. Growers take base elements, such as carbon, hydrogen, oxygen and nutrients (N, S, P, K, Mg, Ca, Na, Al, B, Cu, Fe, Mn, Zn, Mo, Se, Ni, Co, Si, Cl, etc.) and through the plant, turn them into yield, protein, oil, nutraceuticals, enzymes and more — the agricultural equivalent of platinum, gold and silver.
Let’s look at just one example of agronomic alchemy. One of our goals as wheat farmers and agronomists is to:
1) Maximize grain yield
2)Maximize N concentration in the grain removed. The end function we’re concerned about is the storage of N as protein
When we measure per cent protein, what we’re really measuring is the amount of N stored in the and timing requirements of just four elements for 60 bu/ac HRS wheat (Fig. 1). The stated element requirement will be greater for higher protein content and greater yields. Element balance and timing are key considerations.
The red shaded zone is where peak element demand and balance is critical. Now also consider that this represents only six to seven weeks of a crops life. The “pull pressure” that the crop is putting on the soil (and the farmer’s alchemy abilities) is immense!
Consider potassium (K) and observe that the demand curve is nearly vertical between 700-1,000 growing degree units (days). Given this, is it any wonder that we focus so much on N to K ratios when interpreting tissue sample analysis? Given all of this, why do so many experts poo-poo the importance of K management in optimization of crop yields/quality? While S is not depicted, the Sdemandcurvesareverysimilar toN, hencethecriticalattention paid to N to S ratios throughout every crop’s life.
We will need to consider the amino acid profile of the protein that we have concentrated. Can we manipulate amino acid profiles? How would we do that? What elements, rates, balances and timings affect will amino acid profiles?
As a consequence, agronomy is very much both a science and an art. Transmuting base elements into highly valued nutritional compounds, like the several amino acids loosely grouped as protein, while fighting biotic and abiotic stresses (Fig. 2), is very much agronomic alchemy in the purest sense.
Going forward there will be many opportunities for growers to find transmutation value. There will be many questions about how to get there. Questions like:
How do I manage base elements on my farm to produce a nutrient dense crop?
What elements, amounts, balances and timings will optimize this nutrient density?
How can I create value added end products?
What factors govern a more balanced amino acid profile? Can I manage for that balance?
How can I get more selenium (Se) into my HRSW and take advantage of the huge premiums afforded by high-end markets?
What elements do I need to carefully manage to drive cadmium (Cd) out of my durum wheat?
And this is for only one crop we grow! There will be dozens of questions for every crop.
As we focus on more yield and enhanced quality, the greater the pressure of biotic and abiotic stress management. As these pressures mount, the intensity of agronomic alchemy must match and overwhelm the pressure.
Ladies, gentlemen, boys and girls… step right up, listen and watch closely! In the next four decades, we must grow the equivalent of the last 10,000 years of humanities’ food, fuel and fibre production. Agronomic Alchemy will be a very big piece of the puzzle!
As a consequence, agronomy is very much both a science and an art