February 19th, 2019
The Evolution of Crop Nutrition - Copper
One of the most complex topics in crop production is fertility. The soil is a dynamic place and plants are just as intricate. We are just scratching the surface of where we can take fertility, but we are getting better every year. Whether we are discussing macronutrients and some better understood nutrients like nitrogen, or a micronutrient such as copper – we can begin to discern how to evolve our approach to fertilizing and ultimately, feeding a high yielding crop.
So what do we know about copper in crop production?
- It’s essential to all plants, meaning any crop in western Canada will not reach it’s full potential without adequate amounts of it.
- Cereals have the highest likelihood of an economic response to copper, BUT they aren’t the highest users of copper! (read on for what crop is).
- Lodging in many instances is actually due to a shortage of copper – noted most prominently in cereals, but also true in other crops like canola. This is due to it’s role in lignin formation in the plant.
- Copper must be within millimetres of distance of the root for the root to be able to take it up!
- Copper is instrumental in the proper function of flowering in crops.
- High nitrogen levels and organic matter levels (>6%) can actually decrease availability of copper causing latent deficiencies of copper.
So, we actually know quite a bit about copper! And we are learning more every year. But we want to highlight 2 points in looking at evolving copper nutrition:
First - Copper uptake. We know with a high degree of confidence exactly what a crop will use per acre when it comes to copper. Much like we do with nitrogen for example. If we are talking nitrogen, we know it takes roughly 2 lbs/ac of N to produce 1 bushel/ac of wheat! Now let’s approach that with our knowledge of copper uptake per bushel.
One bushel of spring wheat is actually going to take up 0.53 grams of copper. So if we look at a 60 bu/ac wheat crop, we need to ensure we are supplying it with 32 grams of copper to hit our target yield. This is an approach we should be looking at taking when it comes to all essential plant nutrients, in all crops.
The second point we want to highlight is copper proximity to the root. Many read the above uptake numbers and thought “Good thing I put 2 lbs/ac down every other year, I’m set”… Not quite! Copper isn’t mobile in the soil and stays within millimeters of where it is originally placed in the soil! Now, if we look at the need for proximity to the root for ability of copper to be taken up in all actuality, we aren’t getting 2 lbs of Cu with constant availability to the crop. Actually, if we were to put down 2 lbs/ac of a 12.5% granular copper product which is about half an ice cream pail, the spread over a square meter would be very sparse compared to the number plants in that square meter. Not nearly enough feeding sites to get that crop the right amount of copper.
Now, if we were to take an agronomically progressive product that coats each of the granules of a seed placed blend with copper for example, we can actually apply the right amount of copper for that crop AND maximize the number of feeding sites for the crops because we have higher rates being applied! This increases the efficiency, mitigates deficiency and helps increase yield.
If you are looking for a more effective way to fertilize crops with copper, or any other nutrient, please contact us to discuss YaraVita PROCOTE.
Oh and by the way, canola is the highest user of copper on a per bushel basis!
For more agronomic information contact your local Yara agronomist.