We spoke to farm consultant and long-term fieldmargin user, Niels Corfield, about the importance of soil monitoring and how farmers can improve their soils. 

Niels Corfield is an independent farm advisor, and educator who is focused on helping farms transition to regenerative practices across the UK and Europe. He advises and trains on: soil health, planned grazing, agroforestry and whole farm planning.

He uses fieldmargin with his clients and on his courses for mapping, planning farm and infrastructure layouts, and to help farmers adopt best practice management.

Soil health is a key focus for Niels. He is a strong advocate of using visual assessments, which don’t require expensive equipment or lab analysis, to look at soil structure as a starting point for assessing the condition of soils on farm. Read on to find out why, how to improve your soil health and some ideas for assessing soil health and recording your findings in fieldmargin.

Why is monitoring soil structure important?

Two of the key things that plants need are air and water; these are vital for healthy growth. Often we focus on nutrient availability when we analyse soils but a better crumb structure will result in soils that are easier to work and more absorbent.  This results in less surface runoff and erosion, better water storage capacity, reduced waterlogging and better numbers across the board.

This year has really highlighted how reliant UK agriculture is on year round rainfall. Now, with climate change, we are moving to seasonal rainfall patterns: wet winters/dry summers (3 years in 6 have been drought years, often with very wet winters). I have monitored over 100 farms, from Scotland down to the South Coast and the story is the same. 

The moisture stress we have been experiencing this summer in the UK is a strong driver to capitalise on water resources that are available in the winter and bank them for summer. At the moment in the winter effectively all our water is running off – we need to be capturing it to make the most of our winter water availability to drive growth in the season and prevent access issues off-season.

For livestock farms this lack of water in summer means stocking rates are having to be reduced. With best practice grazing management, better soil health and water use efficiency we could potentially double or triple stocking rates.

What are some of the ways that farmers can assess their soil health?

With farmers I mostly focus on visual soil assessments such as spade tests, soil structure assessment and infiltration rates.

I use the margins or under the hedge as a control to show the potential of a soil. Lots of the farmers I work with have never really looked at their soils before. Field margins set the bar for where their soil health could be compared to where they are at the moment. And they allow producers to understand what their own soils look like when they are healthy (with good aggregate structure).

What are some of the ways farmers can improve soil health?

A key driver for soil health is roots and rooting. We need to get away from the soil’s native blocky structure to something more open with pores so that roots can get down to moisture. Often on farms we find very shallow roots (2-3cm is common!). 

In order to improve we need to follow the soil health principles:

1. Maximise the effect of the living root – root exudates feed the living organisms in your soil
2. Covered soil, dense swards – use residues/leaves to protect soil from the elements
3. Minimise tillage – to preserve aggregate structure and reduce compaction
4. Maximise diversity in your planting and rotations – this feeds diversity below ground
5. Feed soils with organic matter – this provides soil organisms with energy
6. Rotationally graze animals – on pasture, cover crops
7. Minimise the use of chemicals and synthetic fertilisers

Visual assessments to measure your soil health and how to record them in fieldmargin 

Here are some simple ways to can start to assess soil on your farm and record your findings in fieldmargin so that you can compare soils on your farm and track improvement.

Making notes with fieldmargin

You can use located notes to record the findings of your soil assessments. To make a note: 

• Open your farm in the fieldmargin app and tap on the ‘+ Note’ button in the bottom left. 
• Give your note a title, if you want you can add a description or photos but you can also add these later on.
• Set a location for your note – you can use your phone’s GPS to add your note where you are in the field. To do this tap on point and tap on the crosshair symbol to go to your current location. You can also attach the field that you are in so that the note appears on its history. You can add multiple points, for example if you are taking multiple samples for soil analysis.
• Save your note. Once you have saved your note you can use comments to add observations or readings and add photos by tapping on the camera icon.
• If you want to take follow up samples of the field you will easily be able to find the same spot to take them from and all your readings will be on hand for comparison.

Spade samples

Use your spade to dig up a cube of soil. Put the cube in a tray. 

• Look at the difference between top soil and sub-soil layers
• Measure the depth of the top soil layer
• Gently break the block apart – what is the structure like? Is it crumbly or blocky?

Make a note on fieldmargin of where you took your sample, your observations and add a photo of your sample. 

Get more complete instructions on spade sampling here.

Infiltration with the Drain Pipe Method

This will help you understand how easily water is able to penetrate your soils. This is based on a method shared by Cranfield University. 

You will need: Pieces of drain pipe 15cm long by 16cm across, insulation tape, a ruler, a hammer, a scrap of wood, a plastic bag/sponge, a stopwatch and water.  

1. Prepare the pipe by attaching one piece of tape (A) around the outside of the pipe, with the lower edge of the tape 5 cm above the lower edge of the cylinder. Put a second piece of tape (B) is attached inside the cylinder, 5 cm down from the upper edge of the cylinder.
2. Using a hammer and block of wood, drive the ring to a depth of 5 cm into the soil (i.e. to the depth marked by tape (A). Insert the ring evenly and gently minimising soil disturbance.
3. Place a plastic bag or sponge in the bottom of ring and then fill the cylinder with water. Or pour the water carefully down the side of the ring so as not to disturb the soil. Fill the cylinder with water to the top edge.
4. Observe the water dropping in the cylinder until the water level reaches the upper part of tape (B). At this point start timing the rate of water fall.
5. When the level of the water drops to the lower edge of tape (B), stop the timer and record the measured time.
6. Calculate infiltration rate (mm/hr) by dividing the width of tape B (mm) by the time taken (hr).
7. Record your test location and infiltration rate using a note on fieldmargin. 
8. Repeat the process 3 times for each location and take an average. 

How to classify your infiltration rate

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Ready to start recording your soil health data with fieldmargin? 

You can find out more about Niels Corfield and the courses and services he offers on his website.

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