Nitrogen Fertiliser: A Simple 4-Season Framework

Planning nitrogen fertiliser use starts with the crop: what it needs, how it is developing and when an application fits its growth stage. A seasonal framework helps organise the year, but crop-specific guidance should determine the timing.

For UK growers using NOxTO Nitrate, this means scheduling applications around suitable crop stages and using the quieter months to review results and prepare.

The month ranges below reflect UK seasons and provide a planning guide. Always follow crop growth stages, local conditions and NOxTO’s application guidance when deciding when to spray.

How does NOxTO Nitrate work?

NOxTO Nitrate uses daylight-driven photocatalytic technology developed by Crop Intellect. Applied to leaves as a liquid spray, it converts atmospheric nitrogen oxides (NOₓ) into nitrate, a form of nitrogen available to plants.

Conventional nitrogen fertilisers supply nitrogen directly. NOxTO is designed to support an integrated crop nutrition programme, including opportunities to reduce reliance on conventional nitrogen inputs. It should not be treated as a guaranteed replacement for a crop’s full nitrogen requirement.

Find out more about NOxTO Nitrate and its technology.

Spring (March–May): Match applications to crop development

Use spring crop inspections to identify the relevant application stage. Calendar dates alone are not enough: crops in different fields may reach the same stage at different times.

NOxTO’s published guidance includes:

• Cereals: 1 L/ha at T1 and T2, with growth-stage windows of GS31–33 and GS38–40, plus an optional GS45–47 timing. When T2 falls within 14 days of T1, use 0.5 L/ha at T2 and another 0.5 L/ha at T3.

• Vegetables: 1 L/ha once plants have 4–5 true leaves, repeated every 4–6 weeks.

• Maize: 1 L/ha at the 4–6 leaf stage, followed by another 1 L/ha four weeks later.

These stages may fall outside spring, depending on the crop and sowing date. Follow the crop’s development rather than moving an application to fit a month.

Summer (June–August): Follow the programme for your crop

Where the crop programme calls for repeat applications, record each treatment and check when the next is due.

• Potatoes: Start at 80% ground cover with 0.5 L/ha. Repeat every 7–10 days, to a maximum of four applications and 2 L/ha per crop.

• Forage and amenity grass: Apply 1 L/ha after each mowing or every four weeks.

Check the full application and dose-rate guidance for water volumes, mixing instructions and other crops before spraying.

Autumn (September–November): Compare results and plan the next crop

Use your field records to assess how the programme fitted your farm. Record conventional nitrogen inputs in kg N/ha alongside NOxTO applications, crop stages, yield and quality.

If you are comparing programmes, include a clearly recorded standard-practice area where practical. Note differences in soil, crop condition and weather when interpreting results; a yield difference alone does not establish its cause.

Discuss any proposed nitrogen reductions with your agronomist before building them into next season’s plan.

Winter (December–February): Turn field notes into an application plan

Prepare a simple record for each field covering:

• Crop and sowing date.

• Target application stages.

• Planned product rates and quantities.

• Actual application dates and conditions.

• Harvest yield and relevant quality measurements.

Use winter to check product guidance and resolve questions about the intended spray programme. Having these details ready makes it easier to act when the crop reaches the appropriate stage.

Frequently asked questions

Does NOxTO replace conventional nitrogen fertiliser?

NOxTO is intended to work within an integrated nutrient management programme. Any reduction in conventional nitrogen should reflect the crop’s requirements, agronomic advice and evidence from your farm.

Does NOxTO need direct sunshine?

NOxTO’s FAQs state that diffuse daylight can activate the technology. This does not mean an application is appropriate at every crop stage or in every season.

Should NOxTO be applied in all four seasons?

A four-season framework includes planning and reviewing as well as spraying. Follow the crop-specific application guidance rather than assuming every season requires a treatment.

For help planning your programme, email info@noxto.co.uk or call 01772 805 996.