Soil Tests

Know your Soils #12: The Soil Health Principles

Know your Soils #12: The Soil Health Principles 5184 3456 Soilmentor

Welcome to the twelfth, and final, instalment of our Know your Soils series sharing practical tips for monitoring the soil health on your land.

“If you can’t measure it, you can’t improve it.


7 Soil health mantras to follow on your farm

Insights from Niels Corfield, Soil Health Advisor

How do you build soil health? Below we share the six soil health principles to follow on your farm. Implementing farming practises and any new ideas which encompass as many of these principles as possible will get you firmly on the path of regenerative farming. With every decision you can use these principles as a checklist to guide you to the best tool to move forward to build a regenerative farming system.

 

 

1. Living Root

Living plants have living roots, they photosynthesise and transmit energy into the soil. This energy is feed for the beneficial soil organisms at work, creating aggregation in the soil.

2. Covered Soil

It’s best to have living plants in the soil, as then you have living roots. But the next best thing is to ensure you cover ground with plant residue, e.g. with a terminated cover crop

3. Minimise Disturbance

Ploughing disturbs the soil organism population, preventing them from doing their necessary work to maintain healthy soil. Reducing cultivation or going no till keeps them happy!

4. Diversity

A diverse range of plants in the soil means a diverse range of roots and a diverse diet for the soil organisms the roots are feeding. Roots have unique functions e.g tap roots bring nutrients up from deep in the sub soils and legume roots fix nitrogen directly in the soil.

5. Feed soils

Feeding the soil with compost, manure or compost tea will directly increase soil organic matter levels and provide plenty of food for worms!

6. Incorporate Animals

Grazing livestock in a rotation is beneficial for increasing soil organic matter, terminating cover crops and decreasing weeds in your fields. Why not try mob grazing?

7. Minimise Chemicals & Synthetics

Adding chemicals can undo the good work you put in for the principles above — pesticides kill soil organisms, fertilisers make plants dependent and herbicides kill living roots.

 

 

Microbial activity in the soil will lead to good soil structure; if generally improving soil health is your first objective then fostering microbial activity is a good place to start. Feeding microbes directly with manure or compost is one way to do this, or encouraging grass plants to grow bigger faster is another. Different grazing practises offer ways to achieve this too.

What management practises have you found useful for building soil health? We’d love to hear from you – send us an email to info@vidacycle.com

 


See our free online soils guide for soil tests you can do at home and find out how our app Soilmentor helps you record & learn how your soil is changing.

Hannah Steenbergen – 42 Acres, Somerset

Hannah Steenbergen – 42 Acres, Somerset 5184 3456 Soilmentor

Hannah Steenbergen is the farm manager at 42 Acres Farm , a 170 acre working farm and garden which is home to the 42 Acres Somerset Retreat Centre. Until this year much of the land was untended and wild, so there is an amazing amount of wildlife. Hannah’s plan is to create a small-scale diverse regenerative farm where they use minimal inputs, foster biodiversity and increase the fertility of the land.

“After we made hay the field was a buzzard playground! Hay making revealed all these small mammals. There’s amazing wildlife at the farm, we want to keep it that way whilst also bringing the land into production.” – Hannah, 42 Acres

On the farm she has introduced a small beef herd of Shetland cattle, which are 100% grass-fed and managed with ‘mob-grazing’.The garden, greenhouse and polytunnel are filled with delicious vegetables, salads and plants grown by Head Gardener Arek. There’s also a flock of Khaki Campbell ducks waddling around the garden and laying eggs. Hannah grew up on a biodynamic farm in North Yorkshire and is committed to following regenerative agriculture principles as she takes the 42 Acres farm forward.

The aim is to build soil health through clever grazing management with their growing number of livestock, moving them around the pasture regularly, ensuring grass has time to regrow and organic matter is continually incorporated into the soil. The farm is in a very wet area, so increasing the soil’s capacity to hold water is very important, that way they can prevent run-off and keep topsoil and nutrients on the land.

The Soilmentor app allows Hannah to monitor how the soil is changing, and if she is in fact moving towards her goals to build soil health at the farm. Her first soil tests clearly show where she started, and with testing every 6 months, she will quickly get an idea for how the soil is changing with each new farm decision and management practise put in place. Plus it can be fun! Hannah said “I particularly enjoy the earthworm tests, identifying the different types of earthworms is very interesting. The infiltration rate is also very interesting, it was completely different in our pasture vs roto-tilled veg plots. I feel like I’m understanding more about soils all the time.”

For Hannah it’s very important to become a financially viable small scale and diverse farm, with a social impact. As the farm is in its first year, Hannah and the team are figuring out what the land would be best used for, and the soil tests will give a good indication of things to try out. By monitoring and understanding the soil health now, she has taken important first steps to ensure healthy soils on the farm.

 

What are Hannah’s management objectives?

  • Increase soil health on the farm
  • Understand best grazing techniques and optimise grass growth
  • Maintain and increase biodiversity above and below ground

 

What is Hannah measuring?

  • % of undesirables % of bare soil
  • % of grasses, broadleaves, no. of species of each
  • VESS (1-5)
  • Earthworms
  • Infiltration
  • Plate meter

 

Interested in using Soilmentor to monitor soil health and manage your farm both above and below ground?

Buy the app here and sign up for our newsletter

Video series: How to monitor your own soils

Video series: How to monitor your own soils 1024 512 Soilmentor

To help you get started with soil monitoring watch our videos on how to do key soil tests, use the Soilmentor app and look at results on the website.

 

VESS TEST

Learn what to look for when you visually analyse your soil structure:

 

EARTHWORM COUNT

The best technique for counting earthworms in your soil sample:

 

SLAKE TEST

Watch how to collect a soil sample in the field and see how well your soil structure withstands water:

 

HOW TO ANALYSE YOUR RESULTS

How to log in to your Soilmentor account and analyse your results:

 

RHIZOSHEATHS

This is an additional test to assess biological activity, although not considered a key test. Find out what to look out for:

 

INFILTRATION RATE VIDEO COMING SOON..!


See our free online soils guide for soil tests you can do at home and find out how our app Soilmentor helps you record & learn how your soil is changing.

Know your Soils #11: The VESS Test

Know your Soils #11: The VESS Test 765 428 Soilmentor

Welcome to the eleventh instalment of our Know your Soils series sharing practical tips for monitoring the soil health on your land. Keep an eye out for our bitesize videos and fact sheets on simple tests you can do yourself on farm.

“If you can’t measure it, you can’t improve it.


How to visually assess your soil structure

Short video created by the Soilmentor Team

Assess the quality of your soil structure for yourself with a spade, tray, ruler and smartphone. Soil structure shows how much biological activity is happening, how well water can infiltrate downwards and how well plants are being nourished. It is core to soil health!

It takes some practise! This short video will show you what to expect:

 

Scoring your soil sample with the VESS chart

Once you have measured the top and bottom depths of your sample, you need to score each one using the VESS chart.

When scoring your sample the VESS guidelines encourage you to ask yourself: Are the clumps angular? Do they have roots running through them? How easy is it to break them down? How porous are they? With gentle pressure breaking them down what size are most of the clumps?

We found many farmers find these questions quite difficult. In the video we simplify the process: it is easiest to observe what soil looks like when you break it apart during the test. If the pieces are mainly angular then give a score of 3-5 and if they are mainly ‘bobbly’ or crumb-like give a of score 1-2. Don’t understand what we mean by ‘bobbly’? Watch the video and you will see! The app helps you with the scoring when you are out in the field too.

 

What does a healthy soil look like?

Well aggregated soil gets first prize in the VESS test! This means that the soil particles are in a crumb structure: there are smaller particles holding together around plant roots.

Soil is aggregated by biological activity; microbes and soil organisms digest organic matter and glue the soil particles together.

Aggregated soil is good because it allows air and water to percolate and store between the particles, which fosters plant growth and supports all soil flora and fauna to thrive.

Soil may lose it’s aggregation structure due to compaction or a lack of biological activity. If you work on improving your soil with the 6 soil health principles you can regenerate it, restoring it’s life and aggregation.

 


See our free online soils guide for soil tests you can do at home and find out how our app Soilmentor helps you record & learn how your soil is changing.

Know your Soils #10: Soil Test Calendar

Know your Soils #10: Soil Test Calendar 1754 1240 Soilmentor

Welcome to the tenth instalment of our Know your Soils series sharing practical tips for monitoring the soil health on your land. Keep an eye out for our bitesize videos and fact sheets on simple tests you can do yourself on farm.

“If you can’t measure it, you can’t improve it.


When and how often should you do soil tests?

Soil test calendar created by the Soilmentor team

Taking the first steps on your soil monitoring journey involves some essential decision making! Firstly, which soil tests are right for your farm as well as when and where you are going to do them?

Certain tests are best done at certain times of year, and like most things in farming, this is due to the weather. On the calendar you can see the key soil tests, when and how often to do them. Choose a minimum of 3 of the key tests and ideally do them all on the same day.

Deciding when and how often to do the tests

Deciding which fields to test

If you want to get an overview of how your soil is doing choose fields which are managed differently, for example, one arable field, one permanent pasture, one herbal ley and so on.

A few farmers have wanted to better understand how soil changes across their rotation, or under cumulative years of a herbal ley. In both these cases, choose one field from each part of the cycle to look at how the soil changes over time.

If you are concerned about the performance of different fields choose to test a couple of your worst fields and a couple of your best and then try different management practices to improve the worst ones so they look more like the best.

Choose fields where you can experiment with different management practices and make changes, so that the results from your soil tests can inform what to do next. If you found poor soil on a field under a restrictive stewardship scheme it could be frustrating that you can’t do anything about it.

Most importantly, only choose as many fields as are manageable and which are easily accessible, ideally not too far from each other. Planning to test 3 fields and doing it is better than planning to test 6, feeling overwhelmed, and not doing any!

Where to do the tests on the field

As a basic rule you want to do each test a minimum of 3 times on each field to get a representative sample. It’s important to not do them too close to the edge of the field too. Certain tests such as the plate meter are better conducted more randomly – for these you can also try walking a W in the field and testing along it. 

If you want to get the most accurate representative sample do 1 test every 8 acres in a field, but sticking to the rule of 3s is easier and will give you good results too!

Once you’ve decided on the location of your sample sites within each field, you can add the exact GPS location of the sites into the Soilmentor app, so you can make sure to return to the same sites for a more accurate comparison next time you go out testing! Read more about this feature here.

To remind yourself of the different soil tests you can choose from, and how to do them, see the full list here.

 

Here is a PDF of the Soil Test Calendar which you can print

 


See our free online soils guide for soil tests you can do at home and find out how our app Soilmentor helps you record & learn how your soil is changing.

Know your Soils #9: The plate meter

Know your Soils #9: The plate meter 470 351 Soilmentor

Welcome to the ninth instalment of our Know your Soils series sharing practical tips for monitoring the soil health on your land. Keep an eye out for our bitesize videos and fact sheets on simple tests you can do yourself on farm.

“If you can’t measure it, you can’t improve it.


How to maintain productive grassland

Insights from Alex Heffron, Welsh farmer and regenerative agriculture enthusiast

Plate meters allow farmers to measure and monitor the volume of forage they have across their fields and farm. This is a very important tool for understanding how to maintain productive grassland and extend the grazing season.

We travel to Wales, to meet Alex Heffron, from Mountain Hall Farm, who produces Jersey raw milk and beef. He’s a first generation farmer, managing 13.5 acres of grazing and 100% pasture fed livestock. So you could say grass is his bread and butter!

Calculating forage volume is an essential tool for Alex to manage food supply for his animals while maintaining and improving grass and soil health. He regularly moves his cattle to new pasture using a Holistic Planned Grazing framework and mob grazing.

It’s time for you to meet Alex’s good friend, the plate meter:

Every time Alex moves animals to new pasture he takes a plate meter reading for that field so he can calculate how much grass is there, and when he should move them again to ensure optimum regrowth of the grass.

Plate meters measure the height and density of the sward. It takes the average height in compressed centimetres and converts it to kilos of dry matter per hectare using this equation: [average sward height] x 125 + 640 = [forage volume] kg DM/ha.

For example: if there’s 4000 kg DM/ha in Alex’s field and he aims to leave 2500 kg DM/ha to ensure grass regrowth, then there’s 1500 kg DM/ha to graze. If the field is 1 ha and there are 10 steers each weighing 400 kg which need to graze 80 kg DM/ha per day, they will last 5 days in that field.

How to take a plate meter reading

The same calculation could be worked out with a sward stick (a sort of paper ruler), but Alex finds using a plate meter less time consuming and more accurate. Manual and electronic plate meters go by a many names: PLATE meters, pasture meters, rising plate meters, falling plate meters. They are all in fact measuring pretty much the same thing.

By plate metering and moving his livestock around different grazing areas Alex maintains a good supply of grass, giving it time to regrow. He uses the Soilmentor app to record plate meter readings and observations, tracking how his forage and fields change and develop with different farm management practises.

“The advantage of using Soilmentor is that it’s an easy and convenient way to record and keep that information handy. It will be interesting to analyse each year the levels of growth and speed of re-growth. It’s another way that I can assess if our management is improving our grazing.”

Even better, taking a plate meter out is another good reason to walk around the fields and visually assess grassland. Alex observes forage diversity, grass condition, trampling, manure quality (indication of rumen health), and how wet or dry the ground is. This observational library is central to continued learning and the evolution of Alex’s farming practises.

Plate metering can be used in different pasture management contexts other than 100% grass fed too. Taking readings across a whole farm gives an overall picture of forage volumes and if there is any grassland underperforming. It’s important not to let the volume drop too much as winter approaches, otherwise grass growth rates will be low in the spring.

 

Resources

Using a plate meter – AHDB Dairy

Expert Guidance on using a plate meter – Farmers Weekly


See our free online soils guide for soil tests you can do at home and find out how our app Soilmentor helps you record & learn how your soil is changing.

Know your soils #8: The most important thing you can do for your soil

Know your soils #8: The most important thing you can do for your soil 1600 900 Soilmentor

Welcome to the eighth instalment of our Know your Soils series sharing practical tips for monitoring the soil health on your land. Keep an eye out for our bitesize videos and fact sheets on simple tests you can do yourself on farm.

“If you can’t measure it, you can’t improve it.


Try 3 easy soil tests to understand your soil health

After almost a year of supporting farmers with soil testing, the Soilmentor team share insights on empowering farmers to monitor and build soil health for themselves.

It’s clear that we need to build more resilient soils, both for the future of our farms and for the long-term health of the land. Satellite images of muddy waters spilling out of brown rivers after heavy rainfall are hair-raising. Soil health advisors are certain this scenario is avoidable, it’s all down to how land is managed.

If this is the case then building soil health should be one of the top priorities on every farm, but how do farmers do this? It starts with soil testing and monitoring, going out into the fields and seeing for yourself how your soil is doing.

Monitoring how your land is changing with different management practices and what works to build healthy soils and crops is the core of successful farming. This is why dedicating just one day to do a few simple soil tests on your land is the most important thing you can do for your soil this year.

Spring and Autumn are the best times to do soil tests.
Here’s the 3 most important AND EASY tests you can do now using equipment already on your farm.

Do the Soil Test Challenge!

 

1. Slake Test (Wet Aggregate Stability)

The Slake test allows you to really see how well your soil structure holds up in water. It is also an indicator of biological activity. Well structured soil is composed of aggregates, so in the slake test you put a few small pieces of soil in a sieve, submerge them in water and then shake them around quite vigorously. If the small pieces survive without breaking down at all they are true aggregates. The water around them will also remain totally clear. So after heavy rainfall, your soil would retain its structure and even keep little droplets of water in the nooks and crannies of the irregularly shaped aggregates. For non-aggregates there is considerable break down of the pieces and the water can become murky. This implies that the pieces of soil are only held together because of compaction, and as soon as there is a heavy rainfall the soil structure just falls apart and then what’s left re-settles and compacts further – no air gaps anywhere.

You score the breakdown on a scale of zero to eight, eight indicates a soil full of microbes and made up almost exclusively of aggregates. You can then easily record your observations and results using the Soilmentor app – including notes and photos all automatically assigned to the field you are in. Here is a step-by-step guide of how to the test and the simple equipment you need.

We are working with Soil Health Expert Jenni Dungait and have adopted the method she used in her research with farmers on multiple farms in Cornwall and Cotswolds regions. An additional benefit of this test was highlighted by Jenni’s research (soon to be published) which shows that the slake test is an excellent proxy for Soil Organic Carbon.

 

2. Earthworm count

All growers inherently understand the value of earthworms as we see them physically move nutrients around the soil profile. Earthworms are one of the larger organisms in the soil food web, so lots of earthworms is a good indicator of plenty of life in your soil. In the UK, an average of 15-20 worms in a 20x20cm soil pit is considered good. Taking a spade, digging a pit and counting earthworms is a very easy and valuable test and if you are using the app, it will automatically record which field the count was in and give you an average for each field at the end of the day. It’s also easy to look back and compare when you do the count again next year. Here is a step-by-step guide of how to do the test and the basic equipment you need.

There is a more detailed earthworm count you can do based on the work of soil scientist Jackie Stroud at Rothamsted. There are three main types of earthworm: the litter-feeders which break down organic matter on the surface of the soil; the top-soil worms who work on soil aggregation and nutrient mobilisation; and then the deep-burrowers that keep water flowing from the soil surface to deep pools below, as well as increasing aeration and root development. Jackie’s research shows that if you identify numbers of each type of worm, it can tell you what the worms are working on and uncover any changes you might need to make in your soil management to encourage all types – ideally you want to have all three types of worm working in harmony. Take Jackie’s Worm ID Quiz, which is a brilliant way to learn how to identify types of worm for yourself. If you are in the UK, you can also choose to be part of her #30minworms nationwide worm survey, building up a picture of the worm situation in fields all over the country. You can find out more about it here, or we can also send her your results from the app, at your request.

 

3. Infiltration rate

The Infiltration rate test clearly shows how ready your soil is to soak up water when it comes, and indicates the ability of your soil to hold water when it’s dry for long periods. Imagine if every farmer and grower around the land had a clear idea of the average infiltration rate in each of their fields. We would definitely be better equipped to prevent those muddy rivers and top-soil losses. To do this test we use a 150mm diameter pipe and hammer the pipe 75mm into the ground (We have pre-marked this on the side). Then we pour in 444ml of water and time how long it takes the water to infiltrate. If you use the app, it will automatically tell you the average infiltration rate for each field, each year, so you can easily compare between your fields as well as from year to year. Here is a step-by-step guide and list of the basic equipment you need to do this test.

Originally we used a much smaller diameter baked bean tin to do the infiltration tests but we were finding it took over 20 minutes for the water to infiltrate which made it impractical to do in the field. One thought was forcing such a small diameter cylinder into the ground was causing artificial compaction in itself, which is why we have moved to a larger diameter cylinder. We have found this size to be much more reasonable in terms of the amount of time it takes, our aim is that this method that takes a maximum of five minutes in most soils.

 

4. Bonus! Photo Diary

We are going to sneak in a 4th here because it’s not really a ‘test’. Farmers have told us that a photo diary of each field above and below ground is very helpful alongside the soil tests. You can see from the example on Fidelity’s farm below what this can look like in the Soilmentor app. And thankfully the app automatically adds a date and time to each photo and assigns it to the field you are in, plus you can add notes, so it’s all organised for you automatically when you get back home. No more scrolling through photos endlessly trying to find the right one or what exactly it was your were photographing!

The Soilmentor app makes it easy to record these observations in the field as you go, and then turn those observations into graphs and insights. Just a few taps and you have everything recorded, alongside photos showing what you saw both above and below ground. Essentially you can build up a visual diary for each field combined with numerical results from the tests. All those results are easily searchable (no more shuffling through piles of papers to try and find those scribbled notes) and quickly show how your soil health is changing over time. What do you reckon? Are you on board? What’s stopping you? If you have any questions at all just email us! We are here to help.

We believe that if we all take this on the UK can be world-leaders in healthy soils and clean waterways!

 


See our free online soils guide for soil tests you can do at home and find out how our app Soilmentor helps you record & learn how your soil is changing.

Know your Soils #7: The Respiration Test

Know your Soils #7: The Respiration Test 1358 772 Soilmentor

Welcome to the seventh instalment of our Know your Soils series sharing practical tips for monitoring the soil health on your land. Keep an eye out for our bitesize videos and fact sheets on simple tests you can do yourself on farm.

“If you can’t measure it, you can’t improve it.


How much biological activity is there in your soil?

Based on an AHDB GREATsoils video created by Soil Association and Earthcare Technical

The soil respiration test is a way to measure how much biological activity is occurring in your soil. When soil respires carbon dioxide is released by microbes, plant roots and soil fauna.

Decomposition of organic matter by microbes in the soil converts organic nutrients such as phosphorus, nitrogen, and sulfur into inorganic nutrients, which plants are able to absorb. This process is also known as carbon mineralisation, feeding the plants, and the soil.

Soil respiration is indicative of the soil’s ability to support living roots and plant growth. Low respiration rates show that there is a lack of soil organic matter and microbial activity in the soil. This could be down to the soil temperature, moisture, aeration or available Nitrogen.

Solvita has created a special field CO2 probe making it easy to test how much carbon dioxide is being released by the soil. It will give you a general idea of your soil’s natural metabolism and which farm management practises are affecting your biological activity.

In this GREATsoils video, find out how to do the test using the probe:

Soil samples need to be fresh from the field and slightly moist for this test — ideally the field will not have not been rained on for two days. It is interesting to sample fields of different uses such as pasture, arable and leys to see how the soil respiration differs.

Equipment:

For those in the UK can order kits from Solvita in the U.S. directly – please note prices are subject to change. Solvita field CO2 probes, gas tight jars and the CO2 colour chart are included in this set of 6 CO2 probes & jars for $99 (£75). You can get an idea of what the colour chart looks like in Solvita’s video. To stock up on probes you can buy 25 x field CO2 probes for $493 including shipping (£376) which is about $20 (£15) per test. The more you order the cheaper it gets: 50 is $714 (£544), so around $15 (£11) per test.

If you’re based in the U.S. you can link up with Will Brinton at Woodsend Labs to obtain advice and the Solvita equipment you need for this test.

If you’re based in the U.K. you can also get an in-depth assessment of your soil which includes the soil respiration test from NRM.

If you’re interested in trying this test at home why not club together with other farmers who would like to investigate their soil respiration.

Resources


See our free online soils guide for soil tests you can do at home and find out how our app Soilmentor helps you record & learn how your soil is changing.

Know your Soils #5: How well can your soil can hold onto nutrients?

Know your Soils #5: How well can your soil can hold onto nutrients? 5184 3456 Soilmentor

Welcome to the fifth instalment of our Know your Soils series sharing practical tips for monitoring the soil health on your land. Keep an eye out for our bitesize videos and fact sheets on simple tests you can do yourself on farm.

“If you can’t measure it, you can’t improve it.


Can your soil hold nutrients effectively?

A video from the ‘Learning from the Land’ series created by Catchment Sensitive Farming &Innovation for Agriculture

Earlier in the series, we discussed how rainwater can wash away all the precious nutrients in your soil, literally leaking money and resources down the field drains. Try this test at home to discover how good your soil is at holding onto different types of nutrients, specifically positively and negatively charged nutrients:

 

Making sure your soil has a stable structure and a high organic matter content is helpful for reducing nutrient loss. There are six basic soil health principles to follow to ensure your nutrients will not be lost with the next rainy day:

Living Root

Living plants have living roots, they photosynthesise and transmit energy into the soil. This energy is feed for the beneficial soil organisms at work, creating aggregation in the soil.

Covered Soil

It’s best to have living plants in the soil, as then you have living roots. But the next best thing is to ensure you cover ground with plant residue, e.g. with a terminated cover crop

Minimise Disturbance

Ploughing disturbs the soil organism population, preventing them from doing their necessary work to maintain healthy soil. Reducing cultivation or going no till keeps them happy!

Diversity

A diverse range of plants in the soil means a diverse range of roots and a diverse diet for the soil organisms the roots are feeding. Roots have unique functions e.g tap roots bring nutrients up from deep in the sub soils and legume roots fix nitrogen directly in the soil.

Feed soils

Feeding the soil with compost, manure or compost tea will directly increase soil organic matter levels and provide plenty of food for worms!

Incorporate Animals

Grazing livestock in a rotation is beneficial for increasing soil organic matter, terminating cover crops and decreasing weeds in your fields. Why not try mob grazing?

Minimise Chemicals & Synthetics

Adding chemicals can undo the good work you put in for the principles above — pesticides kill soil organisms, fertilisers make plants dependent and herbicides kill living roots.

 

 

There are a few bits of equipment you need to get together for this test, like ordering the dyes. How about doing it together with other local farmers so you can learn together which fields you are losing nutrients from?

Equipment


See our free online soils guide for soil tests you can do at home and find out how our app Soilmentor helps you record & learn how your soil is changing.

Making your soil rain-ready :  Skywatchers it’s time to look down

Making your soil rain-ready :  Skywatchers it’s time to look down 800 533 Soilmentor

This is a guest post by Niels Corfield, soil health, agroforestry and whole farm planning advisor, researcher and advocate.

For graziers and farmers

It’s been a “funny old year” from the wet, water-logged winter-spring to the now, dry spring-summer.
Since we’re in a prolonged dry spell people are watching the sky and “praying” for rain (or at least hoping), I wanted to share some relevant gleanings from visual assessments of soil structure and how they pertain to soil moisture, in these most “drying times”.

To conclude the piece I will attempt to show how these observations could be brought-to-bear on management decisions now, and in the future. With a view to ensuring your soils are “ready for the rain”.

Below are some images of soils under different management. When looking at these images I want you to ask yourself: What can we see here? What is the appearance (the structure of the soil) telling us?

Observation

The first and perhaps most important point to make, is, to make a clear distinction between observations and conclusions (or to cited causes). Not that we shouldn’t draw conclusions, simply that there may be multiple reasons for an observed phenomena.

But the first step to understanding a given situation is observation.

 

Above is an image of a soil under permanent pasture in mid winter.

Q: What do we see in this picture, in terms of the visual appearance of the soil structure?
A: a tale of two (very distinct) layers

So, what, might we say, is the most important difference in the state of these two layers?
1. the upper layer appears darker — it is wet (or well hydrated), and;
2. the lower layer has a lighter appearance — is dry.

 

Soil Structure

If we look a little more closely are there any other aspects of the appearance we can identify?
Well, structure is one of the macro features of soil we can look-to to judge it’s condition and it’s state of “health”.

The two broad categories of soil structure are: aggregated and consolidated.

Consolidated soil is the product of physical bonding, typically, having a uniform and homogenous structure, with angular or blocky sections. An aggregated soil is very different, it’s structure is a result of a biological activity — the secretion of sticky substances — that glue the separate soil particles (sand, silt or clay) into little globs, that have a rounded appearance (they look like mini worm castings). See below for an example of an aggregated soil.

 

A Closer Look

By getting right-in there we should be able to spot relevant, features or characteristics, not otherwise visible. Let’s look at these two layers separately, and see how they can be characterised in terms of their structure.

 

Upper Layer

The upper layer (or turf layer as we might call it) has a more aggregated structure, we can see this because the particles sizes vary-, they are generally small, have a “crumb”-like structure, and are held apart from one another, in a disordered kind of arrangement. Overall, the structure is: non-uniform, irregular and generally open in nature (this can be seen by the large number of small shadows visible in the image).
This is also where the majority of the roots are concentrated. They are densely distributed and are mostly coated with soil, with some showing signs of “rhizosheaths”.
These are all signs of biological activity (or the bi-products of microbial activity).

 

Lower Layer

The section of soil below the turf layer has a quite different appearance. Rather than shadows everywhere from all the nooks and crannies created by the many discrete soil particles, what can be seen is a fairly solid mass, with distinct faces, broken into large angular sections. Between- and within these sections there are cracks, clearly visible.
Generally, where it does break breakdown into smaller fragments, these are still angular and blocky in nature, rather than rounded.
There are roots present throughout this layer, however they are fairly widely distributed and mostly white in colour — indicating they are “clean” and free of soil. Not a good sign as it means the roots aren’t building lots of aggregates.
These visual cues are all indicative of a physical structure, one where the soil particles are bonded in crystal lattice: highly ordered, tightly packed and densely arranged, having a low porosity.

 

Discussion

We can see clear a distinction between these two different soil strata or layers. But what is the significance of these observations?

Hydration

The land has had ample rain so why isn’t the whole of the soil profile hydrated.
If it were water loss due to evaporation (somewhat unlikely in winter) surely it would be the upper layer that would be dry, either through direct losses or through transpiration from the majority of the roots.

If it were lack of precipitation we should see a proportion of the lower lever showing signs of hydration, yet there is a distinct boundary, exactly where the soil structure changes.

What seems most likely here is that the rain that has fallen on to this soil has been unable to percolate into these lower depths, basically ending up moving laterally, and leaving the land (taking some goodness with it).

Why is this significant? Why should we care?

Well we can can say, that, amongst other things, soil is a water store (a reservoir) that holds water from rains (or snow melt) from which plants can draw-on in dry periods.

Generally, we can say that better aggregation allows more water to enter the soil profile and holds more of that for later in the year. This is shown, in this example, because the upper layer of this soil is well hydrated, and is also well aggregated. As opposed to the bottom which is dry, and has a consolidated structure. We can broadly say that this layer and below will hold (and therefore offer) little water to plants come the growing season.

In a drought this maybe the difference of several weeks of additional growth.

We can also broadly say that a better hydrated soil will have more active microbial populations, and thus more microbial activity, meaning more nutrient release, and therefore: healthier-, more nutritious grass plants. Which means healthier-, better nourished animals, with better weight-gain, higher conception rates and improved meat quality.
Allround beneficial.

 

Response

So how are we to respond to these observations? What practices or measures can we put in place to address these issues? What might our objectives be, based on what we can see? Where would we want to end up, over what period?

We can say that these observations are generally associated with poor pasture condition. Either through historic management practices or through some issue associated with cultivation, back in the day.

There is no one right response. Every farm is different and you have to work with the constraints you have. However, whatever response you do try, it is important to monitor as you go so you can see if it’s working.

Sampling

That said, it’s important to note that the image referred to here, is just one sample and as such may not be representative of the whole field.

To get a more accurate picture of the soil condition in a field as a whole, a number of samples should be taken. Or an attempt should be made to return to the same spot each time samples are taken.

Either way, the important point is that samples are representative.

This soil sample has been selected for this piece because it illustrates a point clearly.

Monitoring

With this in mind, we can use the baseline we have from the samples we take, record a measure of topsoil depth typically the upper layer, with more aggregated structure (potentially the turf layer) and look to increase that depth year-on-year. Perhaps using a yearly, or twice-yearly assessment – ideally taken from the same- or close to the same location in that field. The VESS test will also be appropriate for referencing progress/improvements.
Another, more immediate method for measuring success would be forage volume, either with a plate meter or a sward stick. With increasing totals and faster growth rates being valued.
Finally, perhaps the most direct method for assessing water penetration into soils, is the water infiltration rate test. Which is kind of a no-brainer, though that said, it’s really a measure of aggregation — since as aggregation improves, so does infiltration. It couldn’t be more appropriate for this drought July 2018.

 

Soil Health Principles

Once you’ve decided how you will measure success, the next step is to identify interventions/management practices that can help you achieve your objectives.
These may well be novel practices or represent a change in management, as such there’s some consideration to be made when selecting a specific option. So, what’s useful is to have a criteria against which to make your selection.

One tool for making selections (or at least shortlisting) is the soil health principles (see below). Basically, practices that match more of the soil health principles should be favoured (where practical).

  • Living Root — for long as possible, as often as possible
  • Covered Soil — with residues or living plants (leaves)
  • Minimise Disturbance — tillage/cultivation
  • Diversity — in your rotations or mixes
  • Feed Soils — organisms need energy (carbon) to live and be active
  • Incorporate Animals — ideally using adaptive/planned grazing techniques
  • Minimise Use of Chemicals/Synthetics — undoes your good work above

In almost all cases, if improving soil health is your aim, then the main objective is to increase microbial activity, either by feeding the organisms directly or by inducing the grass plants to grow larger and more rapidly (which has the knock-on effect of feeding soil biology also, through exudates).
In general we’re looking to increase residues and residuals, increase trampling and shifting to a lower (or ultra-low) utilisation rate — potentially 10–20%, with 30% being an upper range. Frequent moves and high stock density will facilitate these goals.

 

Suggested Practices

Some techniques and frameworks for improving soil health in pasture.
All these practices are routes to increased soil aggregation. And as such their success can be evidenced by this.

Holistic Planned Grazing (HPG)

A tool to deal with the complexity and variables associated with managing grazing systems, and achieve higher goals, like high animal performance, improved pasture growth and better soil.
As they say “proper planning and preparation, prevents….” In this case, the planning means you are generally better prepared for unforeseen circumstances. So when a drought hits- or an extended wet period you should be better able to react and still achieve those goals.
HMG Grazing Charts are downloadable here. Though you may want some support with getting started.
Otherwise there’s a new app PastureMap which takes much of the work out of the process, especially the recording, and on the fly monitoring. As well as this, the support staff are all planned grazers, so they can provide help with the app and the grazing planning.

 

Mob Grazing

Grazing technique that can help to get the most out of your pastures in any given year, especially in drought and when grazing “into the shoulders”. Extend the season and improve the bottom line. Especially effective when applied in a holistic planned grazing framework.
High stock densities (and frequent moves) reduces over utilisation of grasses through selective grazing and ensures even
Works best with smaller animals, with larger rumen to frame size ratio — animals bred to perform well on “low quality”, all-grass diets (450–600kg liveweight).
After a grazing event, close attention should be paid to: trampling, litter/bare soil and residuals, especially when beginning in this practice. Percentage bare soil can be recorded using a quadrat, explained here.
In drought, trampled residues keep soil moist, and protect open areas in sward from heat, and loss of structure, potentially facilitating germination of shed seed. Low utilisation rates facilitate rapid regrowth of grass plants by leaving plenty of “solar panels” for photosynthesis.

 

Mob grazing system in drought (6th July 2018) // Trampled residues — moist soil


The pics above show some of the results of high stock density grazing. Evidence of trampling and high residuals is clear. With particular interest being from the moisture retained on the soil surface below litter.
Not visible in this image the fact that many areas of the pasture have been heavily utilised (perhaps 60% or more) and some areas are untouched (as well as being untrampled).
Residuals and trampling could be be increased, while at the same time reducing over utilisation of favoured grasses, by increasing the stock density further, say moving twice per day. In these most drying of times. This should have the effect of improving the speed of regrowth (keeping the pasture growing in this dry weather) while improving the sward composition (by reducing selective grazing of favoured plants).

Bale Grazing

This technique is typically carried-out in the dormant season, and can be combined with out-wintering.
It’s a good way to keep the manure and urine going on to the field (with reduced need for mucking-out or housing) while adding residues to the field -when forage is insufficient.
Drought situations also present similar conditions. In this case, where grass is running low (or when you want to just leave more residuals) you can put out stored feed. This will have the effect of trampling the residual hay into the soil, which feeds soil organisms and helps to cover soil, in patchy pastures.

Post bale grazing (10th Dec 2017) — Residues incorporated at soil surface (Jun 2018)


Care should be taken to ration the bales offered, to roll out bales (ensuring an even covering — preventing clumpy dense patches that may be slow to breakdown) and to move animals across fodders by: mob grazing, rotational grazing (higher stock densities mean higher residuals).

These are just two possible techniques that have a proven track record in improving soil health, while supporting high numbers of stock. Increasing sward diversity, either with perennial pasture species or annual forages is another route. See examples presented below:

All these techniques can help to improve soil health and with it pasture health, which in drought translates to longer growth into the dry period and in mature systems, continued growth through the “dry season”.
While also facilitating longer out-wintering through better soil structure, that resists poaching, and providing additional available forage in the dormant season.

 

Convince Yourself: On-Farm Trials

These techniques are all novel, have a degree of nuance to them and of course can be applied alongside existing practice or together.
So, when implementing them there’s a real risk of disruption to the existing operation, and a need to master- or at least road-test these techniques.
For this reason, a period of experimentation is highly indicated.

The most appropriate vehicle for testing novel techniques is on-farm trials.

This could take the form of a “split field” trial – where one half of one field is managed using a new technique and the other half is managed as normal. This is monitored, using a set of tests that can be carried-out across both areas and the results compared. See below for examples.

Some knowledge of variability in soil types is useful. Wherever possible we’re trying to remove variables. So if one part of a field is a different soil type, attempt to split the field through or across that section. So as to have both soil types represented in both treatments.

Side-by-side experiments give the most immediate feedback.

This might start with a single field, perhaps one that is close to the yard – for easy access and monitoring, one that is perhaps average in condition – neither especially good nor bad. Then the two treatments can be compared side-by-side, without the variable of: soil type, aspect etc.

Another option could be to compare different stock densities in one half of the field to the other. For instance: standard rate vs double rate. Then compare: residuals, level of trampling, groundcover and potentially Brix or some soil health tests also. While of course being aware of body condition, fill and overall animal health.
Utilising grazing planning tools, like holistic planned grazing would assist this process. But basically it would mean that on each rotation around the farm when the animals arrived to the test field, the same management would be applied.

At the end of year soil health assessments should indicate success of the trialled technique.

 

Conclusion

This article is a short expose on the process you might go through to assess underlying (soil health) issues and what steps you might take to address or remedy these issues.

There is always more than one way to skin a cat, and I would be wary of presenting any of this information as gospel. Simply that it starts with what can be observed directly, what that tells us about the health of the soil, how we can measure this, and implementing management changes to address the underlying causes of these issues.

This is particularly pertinent during this drought period as everyone is “running out of grass” (in a year when winter rains were, if anything excessive).

The basic thesis is that a healthy soil with soak up all the rain the winter throws at it, let much of that pass through, slowly — thus eliminating flood pulses — but holding the remainder (interstitially) where it can be accessed by crops and pasture plants for growth into hot dry spells (when they can grow best), giving longer growth with less headaches.

Healthy soils irrigate crops in drought — by capturing & storing rainwater.

If you have any thoughts or questions, get in touch: info@nielscorfield.com