IF you haven’t studied Mulder’s Chart, or even know it exists, check out his chart (right) before you read on.
Mulder’s Chart basically provides a snapshot of plant nutrient interactions, but more importantly it clearly shows what can happen if you’ve got too much or too little of required nutrients in the soil.
It is a complex story, but some examples will help ease the brain.
For example, high nitrogen levels can influence plant uptake of boron, potassium and copper, which scientists call an antagonistic effect of too much nitrogen.
High nitrogen can create a demand for more magnesium.
High levels of calcium will reduce the availability of phosphorus, zinc, magnesium, iron, potassium and manganese, with the effect of a reduction in seedling vigour, tillering and plant maturity.
What the chart allows you to see is how nutrients in the soil can influence the availability and uptake of each other.
So you get the idea.
Enter Nutrian director and chemical engineer Dave Seagreen, who is becoming increasingly in-demand to help farmers understand balanced soil nutrition using liquid nutrients.
Essentially Mr Seagreen’s message is that although the cause of synergism is different from that of antagonism, the result is the same – induced deficiencies of the crop if it is not supplied with a balanced diet.
And he has a timely comment to make about nutrient imbalance regarding frost.
“I was with a farmer last year who complained about a frosted barley crop half-way up a slope,” Mr Seagreen said.
“I suspected sodium as the cause and further investigation showed that this was the case.
“The antidote is potassium (K) and used as a foliar spray, it can be a good protector against frost.
“If there’s no K present and excess sodium, the plant just sucks up the sodium, inhibiting plant health and making the plant susceptible to frost, even on slopes.
“It can be further compounded if you’ve poured on too much nitrogen (N), because high N levels can inhibit plant uptake of K.
“I think we’re over-using N because it depletes organic matter which can hold 20 times its weight in water.
“If you can increase carbon by one per cent in the top 20 centimetres of the soil, it will translate to holding 10 megalitres of water a hectare.”
Stay with the writer, I told you it’s a complex story.
Another antagonist to plant health is excess boron with the antidote being calcium.
Mr Seagreen considers this nutrient is under-rated by farmers.
He said calcium was a major element that is another tool towards improving soil nutrient balance, which is the company’s raison d’être.
It is reflected in trial work Nutrian has been involved in with Ausplow Farming Systems and Primaries CRT agronomist and Gnowangerup branch manager Tom McInerney.
Nutrian is now developing the ninth generation ‘nano-size’ Ezy Flow products which are being used in trials with Ausplow using the DBS and its Friction Flow liquid kit.
One of Nutrian’s main products has been Calbud, which is a highly concentrated fully water-dispersible liquid fertiliser containing optimally synergistic ratios of calcium, zinc, nitrogen and magnesium with trace elements, to ensure strong early plant development.
But in recent years, the company has released crop specific products such as Canolabud and Lupinbud with a Wheatbud product in development stages.
Other liquid products include lime, gypsum, manganese, magnesium, zinc, pasture, wetters and trace (a high analysis suspension of manganese, zinc, iron, copper blended with kelp extracts).
“Some of our work also involves developing products that can speed up chlorophyll-building in wheat plants to build up hectolitre weight,” Mr Seagreen said.
“We’re developing products at the nano level because the smaller we can get the particle size the better for more rapid plant uptake.
“I think this is a game-changer and we have about 40pc of our products developed at this nano level.”
For example, a gypsum and liquid lime combination is considered by Mr Seagreen to be the cheapest way to lower topsoil pH and create a more structured soil.
“Liquid gypsum helps strip out the sodium and magnesium, along with aluminium and conditions heavy and high sodic soils, allowing it to breathe,” he said.
“If soil tests are showing high magnesium, which tightens soils, the (liquid) solution replaces the magnesium with calcium which is absorbed by the clay colloids, allowing air (and moisture) to penetrate.
“In WA, we don’t have enough calcium in the subsoil and it’s compounded by aluminium and iron cations which can restrict calcium absorption by plant roots.
“That’s why a lot of our trials are placing nutrients at depth (average 0 cm).
“Our Ezy Flow calcium liquid, for example, migrates through the soil washed down by moisture.”
But according to Mr Seagreen, balancing soil nutrition was a two-pronged process.
“First make money by introducing nutrients (particularly calcium) down the tube to quickly alleviate soil issues in the top 10cm,” he said.
“Secondly start a long-term process to gradually penetrate applied nutrients deeper into the soil.
“Initially you should be assessing soil health through soil tests at shallow and deep levels to give you a broader picture of what you’re targeting.
“I think the penny is dropping about the importance of soil health, its direct effect of crop performance and strategies that can be used to provide a good return on investment.”
Soil is definitely the next frontier in WA agriculture, reflected by increasing activity in soil amelioration as farmers confront issues such as non-wetting sands, both high and low soil pH, aluminium toxicity, sodium and hardpans.