Biostimulants are currently being pushed to help facilitate a reduction in fertiliser inputs as well as to offset the impact of pest and disease pressure, but do they actually deliver? CPM learns how two products can unlock tangible results for growers.

“With so many products coming to the market it’s important that farmers can see the promised benefits first-hand.”

By Janine Adamson

Trial data, hard evidence, seeing is believing – essentially proof that a product or concept works and does what it promises it will. This couldn’t be more the case than for biostimulants, a segment of crop inputs which can sometimes come under heavy scrutiny.

To help to debunk such doubts, Unium’s Andrew Cromie has been focusing on ways to quantify the benefits of the company’s product range, translating scientific theories into practical results. “It’s easy to hide behind scientific jargon and complicated language, but what growers really want to know is ‘what does it mean for me’? From a practical on-farm perspective,” he explains.

“Usually that’s yield related but it could also mean a percentage reduction in applied fertiliser, for example. It’s ok to measure root biomass increase, but so what? How does this offset the problems which growers face on a daily basis?” asks Andrew.

Noting that more growers and agronomists were becoming interested in how to reduce the reliance on applied fertilisers, Andrew instigated a trial with one of Agrovista’s customers – Dennington Hall Farms in mid-Suffolk. The work would centre around two foliar biostimulant products from Unium’s range – Calfite Extra (calcium+ phosphite+ pyroglutamic acid) and Luxor (a nutrient blend+ humic acid+ fulvic acid+ L-PGA).

Andrew says Calife Extra acts as a ‘scavenging stimulant’ designed to improve crop rooting and maximise nutrient uptake, whereas Luxor provides phosphate supply through maximising availability and reducing adsorption in the soil.

Agronomist Hollie Hunter agrees that reducing conventional inputs is a priority for many of her cereal crop growers. “Often the request is to find alternatives to synthetic inputs without compromising yield – this is becoming an integral part of modern agronomic practice.

“However, with so many products coming to the market it’s important that farmers can see the promised benefits first-hand,” she says.

To conduct the field-scale trial at Dennington Hall Farms, Calfite Extra and Luxor were applied to winter wheat (Gleam and Extase) in autumn 2022. The aim was to compare the impact of each product alone, as well as when used together. This was layered with and without the use of Tiros (endophytes) seed treatment, and compared with a control plot which received farm-standard inputs.

Farm manager Ryan McCormack says it was on Hollie’s recommendation that he decided to give the products a go. “We’re moving towards a more regenerative-type farming system but the changes we make have to incur improvements whether that’s related to margin, sustainability or quality. We’d seen that the Unium products tick a lot of boxes, but this is the first time we’ve trialled them on the farm,” he explains.

“I’m looking to measure both yield and crop quality before calculating the return on investment. The uplift has to be significant enough to make it worthwhile.”

With the products promising to improve crop establishment and overall plant health, did Ryan observe visual improvements during the season? He believes so. “Anecdotally, you could see more biomass and a deeper chlorophyll content especially in the plots treated with Luxor. This was improved further by the use of Tiros,” he says. “But I’m looking for more than that to base my decisions on.”

As the season progressed, like many, the 1200ha farm encountered high septoria pressure due to wet weather conditions, as well as increased blackgrass populations. But as the combine heads back into the shed, yields suggest that Calfite Extra and Luxor could indeed be a worthy investment.

The results, which were collated to produce an average across all varieties whether a first, second or third wheat, came in at 10.15t/ha for Luxor alone whereas Tiros plus Luxor yielded 10.32t/ha. This was compared with the average farm standard control of 9.6t/ha.

Of particular highlight was 10ha of Extase second wheat which was treated with both Calfite Extra and Luxor. This came in at 10.56t/ha, compared with the farm standard Extase which yielded 10.14t/ha – a 0.42t/ha improvement.

Ryan says these are positive results. “Because the products aren’t overly expensive, that should be enough of an uplift to make it worthwhile. Plus they were easy to work with, mixed and sprayed well, with a clean tank afterwards.

“The next step is to trial the products again but with different nutritional regimes to see if we can achieve our goal of decreasing conventional fertiliser use. We’d also like to repeat the Extase element of the trial on a larger scale.”

According to Hollie, potential lies in using the products in other crops too. “For oilseed rape, there’s a real benefit to be had in using biostimulants to increase vigour prior to cabbage stem flea beetle feeding. It’s giving OSR a better chance of growing through the pressure.

“Needless to say, solid establishment in the autumn is important for all crops especially when they can face challenges such as sub-optimal seedbeds and pest damage,” she comments.

Unium’s John Haywood says although the company is focusing on tangible results for their product range, it remains backed by robust science. “The most important aspect to consider with nutrients such as phosphorus, is availability. For phosphate, it exists in three pools in the soil but only the inorganic form dissolved in soil water is readily available to the plant,” he explains.

“The pidolic acid found in Luxor (L-GPA) helps a crop to make the most of this availability while increasing nitrogen assimilation. Combining this with the calcium phosphite found in Calfite Extra tricks the plant into thinking it’s phosphorus deficient, so it increases its uptake.”

John explains that in combination, the two products support a plant through the early stages of its lifecycle (30-35 days) and with the move to later drilling, this is even more important.

“Later drilling dates are a key factor in helping to overcome other challenges such as blackgrass, but of course this means cooler temperatures which can prove difficult when establishing a crop. Coupled with the fact soil biology also becomes less active, crops often require additional support.

“Following the recent high grassweed pressure, it’s unlikely growers will want to compromise on cultural controls and IPM best practice, so an application of Calfite Extra and Luxor could help to offset those additional concerns,” he concludes.

This article was taken from the latest issue of CPM. Read the rest of the article here.

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