Using fieldmargin for nutrient management and planning 

Using fieldmargin for nutrient management and planning 

Nutrient management planning matches nutrients in inputs such as fertilizers and organic manures to crop demand.

Good nutrient management is one of the keys to farm profitability. It is also important for your audit records and compliance with regulations.

Plants need a range of nutrients in order to grow and maximise yield. The key macronutrients to look at for crops are Nitrogen (N), Phosphorus (P) and Potassium (K). These are often referred to as NPK. Of these, nitrogen is of most importance for the majority of plants. Sulphur and Magnesium are also important nutrients.

The best time to prepare a nutrient management plan (in the northern hemisphere) is now. This is because late winter or early spring is before crops have started to take up most nutrients.

In this article, we are going to share how you can use fieldmargin for your nutrient management for your crop records this season. 

This includes: 

📲 Recording soil sample results

🌾 Recording nutrient content of crops

📋 Planning application rates

🚜 Checking nutrients applied on a Field Job

📊 Checking total NPK applied per field

💵 Calculating your cost of fertilizer across the farm

When you’re ready, head to the fieldmargin app to try this for yourself.

Recording soil sample results

Soil testing is important to check what nutrients are already available in the soil and work out what nutrients are deficient and should be applied. Doing this at a regular basis is important to make sure you aren’t applying fertilizer unnecessarily so that you can improve farm efficiency and sustainability. Standard tests will include NPK and pH but an increasing number of farms are looking at micronutrients (which can be a crop limiting factor) and soil organic matter as well.

The Soil Mineral Nitrogen measurements described in the AHDB Nutrient Management Guide (RB209) involve soil sampling to 90cm. At least 15–20 individual soil cores should be bulked to give one sample representing the field. When taking samples you should walk in a W shape to make sure that your sample is an average of the field. You can also divide larger fields into smaller testing blocks. This is particularly useful for areas where you suspect there may be a deficiency.

You should take soil samples at a time when nutrient levels are likely to be lowest. This would usually be between September and March after the previous crop has been harvested. This will identify the residual nutrients left in the soil that will be used by the next crop.

You can use notes on fieldmargin to record soil sampling data attached to a field. 

With notes, you can attach the data to the field and also show the sampling location with pins and GPS coordinates. 

You can also upload files with the results of the analysis. This means the data is easy to access in the field and can be instantly shared with consultants. 

Recording nutrient content of crops 🌾

Nutrient management planning matches nutrient inputs (fertilizers and organic manures) to crop or pasture demand.

Part of this is to able to calculate the nutrient and pH requirements of the crop/pasture and then adjust your N rates according to plant N and Soil Mineral Nitrogen. 

You can estimate the amount of nutrients in your crop and pasture using different techniques and measurements. 

You can find resources for how to do this here: 

You can use fieldmargin to make a record of crop establishment of pasture growth whilst you are out in the field. 

For example, you can use notes on fieldmargin to record images for Green Area Index analysis.  

The Green Area Index is a way of measuring how green an area in a field is. It can be used to estimate how much nitrogen has been taken up by crops better allowing adjustment of spring nitrogen applications.

How to record Green Area Index on fieldmargin: 

  • Tap the + note in the bottom right 
  • Attach the note to the field and give it a location
  • Add a photograph in the comment section 
  • The date and time will automatically be saved and it will become part of your field history 

You can also use notes to add future recommendations. This is useful if you work closely with a consultant and can become part of the field history records, easily accessible for audit.  

Planning application rates 📋

When you add fertilizing jobs on fieldmargin you can set the nutrient content of the fertilizers that you are using on your farm so that you can track applied quantities of NPK and other micronutrients. You can track Nitrogen (N), Phosphorus (P), Potassium (K), Sulphur, Magnesium, Calcium, Manganese, Zinc, Molybdenum, Copper and Boron.

When you enter input rates for fertilizers which have nutrient content set up you will see additional rows for each of the nutrients in that fertilizer. You can:

  1. Enter your target quantity of a nutrient to be delivered based on plant requirements (in the example below 120kg N) and have the quantity of fertilizer required calculated.
  2. Enter the planned quantity of fertilizer to be applied and it will show the quantity of nutrients that will be delivered.

You can enter the target quantity of a nutrient or the planned quantity of fertiliser that you are applying.

Add the job to a teammates to-do list 👩‍🌾

Set a due date for the work and share this job with your team by tagging them in it. When a user is tagged in a job they will receive a notification. 

The Job will then become a part of the team’s to-do list Access this by tapping to-do on the bottom menu. You can also view jobs that need to be done for each field by tapping the field.

Checking nutrients applied on a Field Job 🚜

When viewing the inputs on a Field Job you will see additional rows under fertilizers showing the nutrients applied. It also shows the nutrient percentages of the fertilizer next to its name.

Track when work has been completed across the farm ✅

Keep everyone on the team up-to-date. You are notified as soon as a job is done and workers can go straight on to the next task. 

Tracking nutrient use across fields 👨‍💻

Use the Nutrient Report in the Reporting section of the web app to track nutrients applied per field. You can filter the report to change which nutrients are displayed or to only show particular fields.

Click on a field row to expand it and see the individual Field Jobs where fertilizer was applied.

Calculate your cost of fertilizer across the farm 💵

Monitoring input spend is more important than ever. You can add a cost to all the fertilisers that you used on your farm (Read how here.) This will show you a breakdown of the quantity of an input used per field and field-usage.

“Those of you who received a copy of the Guinness Book of World Records for Christmas may be forgiven for flicking through it to see if “fertiliser prices” were featured in the latest edition – as we face the highest ever prices for nitrogen fertiliser, followed closely by just about the highest P and K prices.”  Tim Kerr (Hutchinsons Nutrition Manager) 

The type of input is shown as different colours for Seed, Spray, Fertiliser and other.

You can also monitor farm performance with Gross Margins per field and field-usage type.

With fieldmargin your input and yield data come together to produce gross margins per field and usage.

If you have any questions or need help using fieldmargin you can get in touch with us at or via the chat window in the app and we will be happy to help.

Field Job inputs and reports are a part of our paid subscription. We offer a 14-day trial of Pro for free with no commitment to purchase (you don’t even have to enter any card details!). 

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