Nitrogen efficiency is a hot topic. We lose about 50% of what we apply to the soil and this is not only an issue financially (literally throwing money down the drain), but also agronomically and environmentally.
Excess soil nitrogen means that the microbes that fix Nitrogen don’t have a role to play as they are not getting the signals from the root exudates that Nitrogen is required. So they lay dormant waiting for something to do. This means that the soil Nitrogen that is applied is much more at risk of being leached or volatilized as there is no demand from the plant to take it up. However, the plant does readily take up the N, leading to unbalanced growth. This lush leafy growth is attractive to pests like aphids and diseases.
THE NUTRIENT CHAIN CHART
If we look at the above chart, Nitrogen is 4th in line and it does make sense when you think about it. Boron is the activator and kicks things off. Then, it gathers Calcium and Silicon, the structural components. Only once it’s created the foundation does it look for Nitrogen to provide growth. Soon after, the powerhouses of Magnesium, Potassium, Carbon and Phosphorus show up at the party. So it’s not just NPK and certainly not just N.
When we’re applying N what should we be thinking about?
1. Form of Nitrogen – AN, Urea, Sulphate of Ammonia, CAN?
2. Amount applied – 2/3/4 splits?
3. Timings – March, April, May?
4. Partner Products – Carbon, Sulphur?
Suddenly there are lots of interesting choices. These are all quite traditional, but times are changing quickly. We are finding that biological nitrogen, amino acids and foliar Nitrogen all have big impacts on the crops we grow.
Biology
Accessing nutrition through soil biology comes in many forms. We’ve often discussed how important soil biology is in mineralising and releasing Phosphate from the soil. We should never discount just how valuable soil biology is at releasing and cycling other key nutrients, including Nitrogen.
Growing cover crops is becoming more and more popular and for good reason. Multiple plans/cropping rotations that we see now make full use of five, six, and even 10-way mixes. These cover crops keep all of that soil biology that you’ve worked so hard to nurture, cycling around and the nutrients that go with them. The deeper rooting varieties dig down into uncharted territory to draw valuable nutrients up towards the surface, ready to be utilised in the future.
We can apply beneficial bacteria products such as BIOPLUS T or CONSORTIUM to provide a real kick to the colonies that already exist within your soil structure. This boost really stimulates the rhizophagy cycle (look it up, it’s amazing).
All of these techniques deliver N in the form that the plant wants, meaning a more balanced uptake and a healthier plant that’s more naturally resistant to pests and disease.
Amino Acids
We originally used them exclusively during times of stress be it drought or herbicide use. Now as we are discovering more about how they work and how the plant utilises them, we recommend using amino acids throughout the season. They deliver N to the plant in a very energy-efficient way, by short-cutting the metabolic pathways. When you apply Nitrogen in any form, the plant has to work to break that Nitrogen into the form that it wants. This form is amino acids.
Results show that when amino acids are applied with foliar urea you get better uptake from the urea without taking into account the benefit of the applied amino acids.
Foliar Nitrogen
Similarly to amino acids, foliar N was traditionally used at times of stress. Generally, it was recommended when the crop was starting to drought out and the soil supply was switching off.
We now understand more about how to get the best from foliar products as a whole. With much better efficiency and uptake, foliar nutrition is now recognised to be 4 to 5 times more efficient than soil-applied, meaning that 8 kg/ha of a true foliar is equivalent to 32-40 kg/ha of soil-applied nutrition. This can make a big difference to your carbon footprint. Practicality-wise, however, it’s not suitable to use foliar nutrition throughout the entire programme as you need a good canopy cover to get the best uptake.
Foliar nutrition should absolutely be considered for the last 20-25% of your programme. Don’t hold back either. Go and get yourself the bells and whistles. We have specifically designed our TRINITY product to be an amide Nitrogen complexed with Sulphur & Magnesium to support photosynthesis and this is proving to be very popular as a baseline foliar option to which you can add the other specific macro & micro-nutrients, as required, to get the correct balance for your crop.
Summary
Traditional, conventional, holistic, regenerative. Whichever tag you attribute to yourself (or your neighbour) remember what is important is making sure that you provide the plant with what it needs, when it needs it and in the form that benefits it the most.
