Using nitrogen to manage crop nutrition during dry weather

Natalie Wood, Chief Arable Agronomist at Yara

At the time of writing, soils are currently very dry with only intermittent rainfall in the long-term forecast. What does this mean in terms of crop nutrition?

At this point it may be necessary to apply a second dressing on feed wheat – if it hasn’t been applied already – in order to ensure the optimal balance of nitrogen. This will guarantee an adequate amount of nitrogen in the soil during brief rain showers. If, like last year, weather conditions become extremely warm and dry, crops are going to struggle once again. It’s therefore vital to give them sufficient nutrition early on, in order to help their ability to scavenge whatever water is available at depth (wheat roots grow to depths of more than 2m).

It is important to keep the crop momentum going through this stressful period. If dry conditions continue as the weeks go by, then foliar nutrition, such as potassium, can help. Potassium is important for water use efficiency (WUE) and has been shown to increase WUE even on a crop that’s being irrigated. Potassium is part of the opening/closing mechanism of the stomata – if there is a deficiency the stomata don’t work as effectively. This could result in more transpiration than is necessary due to the stomata not closing properly, which would be detrimental in dry conditions.

“Ensuring that all micronutrients are sufficient gives the crop the best chance to overcome these kinds of abiotic stresses,” says Natalie Wood, Chief Arable Agronomist at Yara. “By taking control and managing nutrition carefully, it’s possible to establish solid crop momentum, even in difficult years.”