Fertiliser Calculator
Select your SoilWorx product, enter your field area and target nitrogen rate, and the calculator will show you how much product you need. Suitable for professional growers, agronomists and amenity managers working with any of our organic and natural fertilisers.
Fertiliser Calculator
Rates are indicative. For tailored advice specific to your soil type and crop programme, contact our agronomic team.
Conversion Calculator
Which product should I choose?
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Product
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NPK
|
Best for
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|---|---|---|
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4-2-3
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Balanced nutrition, general arable, grassland
|
|
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3-2-17
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Potatoes, root crops, high-potassium requirements
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|
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8-2-2
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High nitrogen demand: cereals, grassland, brassicas
|
|
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13-0-0
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Nitrogen-only supplementation, organic systems
|
|
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0-0-50
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Chloride-sensitive crops: potatoes, soft fruit
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|
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Variable
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In-season nitrogen top-up, foliar, fertigation
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Not sure which product suits your situation? Contact our team — we can advise on product selection, application rates and multi-product programmes.
Frequently asked questions
What units does the calculator use?
Field area is entered in hectares (ha). The target N rate is entered in kilograms per hectare (kg/ha). The calculator outputs total product required in kilograms (kg).
Can I use the calculator for split applications?
Yes. Calculate each application separately using the rate for that timing, then sum the results to find your total seasonal requirement.
Can I combine products in the calculator?
The current calculator calculates one product at a time. For multi-product programmes — for example, combining Dynamo with a Sulphate of Potash top-dressing — calculate each product separately and combine the results. Our team can assist with programme design.
Are the rates guaranteed?
Application rates are indicative guidance based on product nutrient analysis. Actual requirements will vary depending on soil nutrient status, crop variety and target yield. Speak to a qualified advisor.
About SoilWorx
SoilWorx is produced at the UK and Ireland’s largest organic fertiliser plant in Newry, Northern Ireland, part of a circular economy that transforms agricultural by-products into high-value fertilisers. Find out more about how we make our products.