Fact-finding mission on US farms

MANY of you will be aware of my recent trip to the United States and of my long-time practical interest in soil nutrition and plant responsiveness.

Over the years we have all tried many products that come in 20-litre drums and eventually, given many away due to inconsistency or ineffectiveness.

One of my many day trips in the corn country of Iowa was to a farming town called Griswold where I met the local agronomist and his farmer clients.

They even gave me several copies of their soil tests, all in parts per million I might add.

So what is the difference between our soil tests and theirs?

For a start their measurement of organic matter is in the 3-4% level and I cannot remember a soil test in Australia with that desirable high level. I assume it is a result of growing 200 bushel plus corn in a dryland situation.

By the way, 200 bushels to the acre is close to 5.5 tonne per acre (13 .6 tonne per ha) and that was an average county yield.

The other unusual issue was their shallow depth of soil testing - about six inches and only very occasionally down to 12 inches.

Right from the outset all my generous hosts explained patiently, they do not go to the levels of soil testing we do.

That does not mean we are wrong by the way.

Many American grain farmers just have a philosophy that what worked in previous years is okay for this year as well and with their government policies on agriculture, I guess that is a reasonable attitude.

There is, however, an increasing number of corn and soybean producers who want more from their crops, especially in these past couple of dryer years.

Enter products like Zinc Ammonium Acetate and Inositol, which are being used more and more in these potential "high" yielding crops scenarios.

Zinc Ammonium Acetate has been around for several years, but the understanding of this unique product has been slow.

The good book describes it as an extraction agent in the soil for making nutrients more available to plants.

It also increases photosynthetic activity when applied as a foliar treatment.

My new Griswold farming friends took me to one of their fields of corn, where they had treated most of the paddock with Zinc Ammonium Acetate and left the obligatory 12 rows untreated.

In goes Paul with a big shovel to dig out some sample plants from each area.

The pictures tell the story however what you don't quite pick up in the photo is the increased dimension of the corn plant in the treated section.

My guesstimate is maybe a 20% bigger girth in the treated plants and both Steve and Dan, who are both well known Iowa technical agronomists, speculate about the larger vascular tissues to facilitate more nutrient and water movement in the treated plant.

The most obvious point in the whole treated block was the much larger root ball that was present under each corn plant.

From an overall perspective the treated area looked infinitely better in crop stressing and wilting with this increased root mass compared to the untreated area.

Even the corn cobs that were picked looked different in size as you can see from the photos.

What will it yield is the big question and the eventual extra income to the family?

Their comments were that it has always done the job for them and they really do not plant anything without one or both of these above plant elicitors.

Topics:  paul mcintosh soil health

Stay Connected

Update your news preferences and get the latest news delivered to your inbox.