Best chance of survival for waterlogged cereal crops

Exceptionally wet weather this autumn means time is running out for growers still unable to drill winter-sown cereals.

Winter wheat can be drilled until January. But leaving it too late  can result in reduced germination and plant populations. This is due to lack of warmth and suboptimal moisture levels for establishment.

As Christmas approaches, many farmers still aren’t drilled up. Some still have a considerable area to sow following early winter storms which caused localised flooding and left standing water on fields.

Growers with waterlogged soils will already be facing major challenges, says Adam Bartowski, eastern regional product manager at Timac Agro.

“If crops are drilled after November, average establishment rates tend to fall below 50%,” he explains.

The season has reached a critical point, with many farmers having to decide whether it’s worth proceeding with late drilling of winter wheat in oversaturated soils or delaying until spring, says Mr Bartowski.

A total soil temperature of 150°C should be reached between sowing and emergence, suggests the Agriculture and Horticulture Board wheat growth guide. This can take a month in crops drilled late into cold, wet soils.

Excessively wet soils run the risk of hard freezing as temperatures drop, which can also induce a stress response in plants. This leads to elevated ethylene levels from poor ventilation, causing crops to mature too early or shut down entirely.

Crop management

“If growers are still looking to capitalise from winter wheat, the best approach to encourage establishment is to combine increasing seed rates with applying a soil conditioner or starter fertiliser,” says Mr Bartowski.

A microgranular starter fertiliser can be added with the seed at drilling. Phosphorous and zinc can stimulate germination, early root growth and nutrient uptake where there’s been less natural microbial activity to provide soil nutrition.

For growers who lack the specialist equipment to apply microgranular fertilisers, Mr Bartowski says another option is to apply a soil conditioner in preparing the seedbed just before drilling.

Correctly formulated soil conditioners can help neutralise acidity when applied at suboptimal pH levels, which can be an issue in prolonged wet soils, particularly those that have had manure applied.

How nutrition can build resilience

Foliar nutrition can help storm-hit cereal crops alleviate potential nutrient deficiencies going into winter.

Persistent autumn rain means soil nutrients are in short supply due to leaching and lock-up, says Chris Bond, crop nutrition product manager at FMC. Building crop resilience is vital for strong growth in the spring, he adds.

“Building a robust canopy before winter is key, it keeps the plants active and ready to hit the ground running for the crucial growing season in spring,” says Mr Bond.

At the same time, it’s important to foster strong root development. Foliar nutrition is one way growers can support crop resilience.

“Many nutrients can be locked-up in the soil during cold and wet conditions. Foliar application can eliminate these risks.”

Manganese, magnesium and copper are some of the key nutrients for cereal crops this winter for building above-ground resilience.

These nutrients all help with maintaining photosynthesis and cell wall integrity.

Root systems

Zinc encourages strong active root systems, which is key for cold stress resilience. But deficiencies are on the rise, with 66% of tissue samples in 2022 showing lack of zinc, escalating to 75% in 2023.

For growers considering a foliar application of nutrients, Mr Bond suggests products containing magnesium, manganese, copper and zinc. Applications can be made at any time after the three-leaf stage when foliage is able to absorb the nutrients.

“By building resilience now with the help of nutrition, crops have a much better chance of weathering the winter and withstanding any further harsh winter conditions, ready to get away during the spring.”