Growers of high-value crops have long used plant tissue sampling to improve fertility and other agronomic factors.
In recent years, however, the popularity of tissue sampling among grain and oilseed producers has sharply increased.
According to those offering tissue analysis services, the driving factors have been a growing interest in more specific reasons for variations in productivity, and a desire to achieve full yield potential.
Why it matters: Knowing what a crop absorbs from the soil, as well as what’s in the soil, can help generate a more precise agronomic picture.
Chris Roelands, a certified crop adviser and operator of the Honeyland Ag-Services analysis lab near Ailsa Craig, said the number of soil samples processed at his lab remains four times higher than the number of processed tissue samples. However, he has noticed growth in the latter over the last six to seven years.
Many of Roelands’ farm clients use the technology to gain a better overall picture of their field fertility levels, as well as a troubleshooting tool to assess micronutrient deficiencies.
“With soil samples, we are extrapolating what we think is going to be available to the plant. That can be very good but it doesn’t always tell you the whole story. If you’re using the plant levels, that’s as real as it gets because that’s what the plant has taken up,” says Roelands.
He adds growers aiming for high management crop production will sample plant tissue even if the crop looks healthy, though its not a common practice.
A & L Canada Laboratories also reports significant growth in tissue analysis requests from row crop producers, particularly those hoping to make in-season adjustments.
Nevin McDougall and Richard Robbins, A&L’s president and agronomy customer service specialist respectively, say wheat growers often use it to strategically increase protein levels. Deficiency identification in corn and soybeans is also common.
“This past year manganese was a common deficiency for soybeans. It was an excellent opportunity to quantify manganese and follow it up with a foliar application,” Robbins says.
While it is possible to take in-season action with tissue sample results, Roelands thinks growers need to ensure they are not relying on short-term fixes.
The real power of tissue samples lies in learning about a given field over time and addressing challenges in and between subsequent cropping years.
“If there’s a major potassium issue in your corn, you can maybe band-aid it at the time, but you can never overcome the entire issue because the amount of uptake is so high,” Roelands says. He reiterates there is a role for in-season action in some cases.
McDougall and Robbins attribute the apparent lag in uptake to a lack of awareness. Despite the potential yield and quality insights, farmers not accustomed to the tool just don’t know about it. A & L occasionally runs webinars to increase awareness.
Even if growers are aware of the option, knowing how to take a proper sample is another consideration.
The basics of taking a representative sample, says Robbins, involves collecting two large handfuls of leaf samples in a 100 sq. metre area. Samples should be taken from different plants, and ideally, from recently matured leaves. The exact process varies from crop to crop, and he encourages growers to seek expertise.
Although tissue sampling is a valuable tool, Roelands says it is no miracle indicator. Efforts at improving how results are interpreted are ongoing.
“Interpretation is a key part…It’s just like soil sampling. Where we’re at is a great starting spot, but there are still situations that leave people scratching their head.”