The recent weather conditions have left winter crops sitting in waterlogged soils, and as a result of this, root systems may be suffering unseen damage, which could impact yields later in the season.
However, Natalie Wood, agronomist and YaraVita & biologicals product manager, says that a timely foliar nutrition programme could help crops recover.
“Strategic foliar applications at T0 – particularly of phosphate and key micronutrients – can rebuild damaged root systems and maintain crop sufficiency throughout the critical spring growth period,” she says.
When soils are waterlogged, conditions become anaerobic. The lack of oxygen causes smaller roots to retract, leaving crops with only shallow primary roots and the above-ground growth begins to exceed what the root system can sustain.
“The longer crops sit in waterlogged conditions, the more damage is done,” Natalie says. “Microbes are starved of oxygen, so they’re not able to mineralise the nitrogen from the organic matter.”
She adds that this makes it difficult to assess how much nitrogen has been accessed over the winter period, adding another layer of uncertainty to spring nutrition planning. Leaching is also a concern, leaving crops deficient just as demand increases.
Foliar applications can offer a more direct route for nutrients to reach the crop, particularly in current conditions.
“Nutrients like phosphate can get into the crop very quickly through that leaf surface, aid root development and rebuild some of that damage done,” explains Natalie.
However, this needs to be planned in conjunction with conventional fertiliser applications and not be viewed as a replacement. “You would probably need to come back relatively soon with your solid application, because that amount of phosphate isn’t enough to sustain the crop.
“It’s enough to kickstart the growth, but it’s not enough for that crop’s demand.”
Driving growth
For cereals, rapid early growth is crucial to mitigate the damage caused by waterlogging. Protecting tiller numbers and rebuilding biomass will directly influence the yield.
According to Natalie, YaraVita CropBoost can help with this as it contains magnesium, phosphate, potassium and zinc. Phosphate, in particular, will help to put on a lot of biomass in a short space of time, as well as promoting root growth to help with potentially dry conditions in the spring.
In oilseed rape, she recommends YaraVita Brassitrel Pro, which contains magnesium, manganese, boron, calcium and molybdenum. According to the company’s research, these are the most likely to be deficient during tissue sampling.
“The boron ensures flowering goes well,” says Natalie. “It’s basically trying to make the grower’s life as easy as possible, getting all those nutrients into one can, one solution, saving them time and effort.”
Proper micronutrient planning not only address defiencies but helps to build resilience within the crop.
“A healthy person tends to get less colds for example, and it would be the same for plants,” Natalie explains. “If you’ve got a very healthy plant, it’s going to be more resilient and better able to fight off some of those stresses.
“It’s not just that we’re covering a lot of bases, but we’re also de-risking that crop. We’re trying to make sure it’s got everything it needs to grow, particularly when we’re building the blocks for yield at this early stage.”