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Written by DENISE ATTAWAY, Clemson University, South Carolina, USA

Healthy crops begin with healthy soil and researchers with the Clemson University’s Sustainable Agriculture Research and Education (SARE) program are teaching farmers how they can benefit from keeping their soils fit.

The researchers teamed up with other agricultural professionals and farmers who have implemented soil health principles by using cover crops, no till and livestock integration to hold a conference to teach about soil health and tools to use to promote healthy soil.

“Soil is one of the most precious resources we have,” said Geoff Zehnder, Clemson SARE coordinator and co-organizer. “We depend on soil for our livelihoods and we must learn how to keep soil healthy so that it will continue to work for us.”

Co-organizers with Zehnder for the Building Soil Health: Principles, Practices and Productivity conference were Kelly Flynn with the Clemson Emerging Crops Program and Buz Kloot with the Arnold School of Public Health at the University of South Carolina.

Many people may take soil for granted and think of it as a renewable resource that will always be around. However, worldwide, topsoil has been lost in the past 150 years and is being lost at rates 10 to 40 times faster than it naturally can be replenished. Currently, 40% of soil used for agriculture throughout the world is classified as degraded or seriously degraded. Gail Fuller is a third-generation farmer from Emporia, Kansas, who spoke about how cover crops can help replenish the soil.

“George Washington and Thomas Jefferson used cover crops to replenish the soil after a harvest,” Fuller said. “In the 1800s, cover crops were known as ‘green manure’ and were widely used to enrich the earth and put nutrients back in the soil. Why did we ever get away from using cover crops?”

Availability of synthetic fertilizers and a lack of understanding of the role of organic matter in soil health are two possible reasons why cover cropping practices have declined in modern agriculture. Also, successful implementation of cover cropping requires some knowledge and experience. But creative management can help overcome some of these issues, Fuller said. 

“Consider the main crops being grown and then determine which cover crops can be grown so that they won’t interfere with harvest and will still have a head start when going into winter,” he said

Fuller said he has learned planting cover crops is a way to increase profits and nutrient cycling, as well as capture solar energy. Jason Carter, a Richland County farmer, started cover cropping about 8 years ago and is seeing benefits.

“I had read about it and was interested in using cover crops as a nitrogen source,” Carter said. “Since we’ve started growing cover crops, we’ve cut back on fertilizer inputs, but are seeing the same yields. We’re saving money because our fertilizer costs are lower and yields are remaining the same.”

Leon Dueck, a dairy farm owner/ operator from Olar, learned about growing cover crops after attending a field day at Carter’s farm.

“We, too, have lowered input costs by growing cover crops,” Dueck said. “We’re also seeing an increase in nutrients in our silage.”

Planting the correct cover crops can lead to better soil health by: reducing inputs, discouraging weed growth, promoting drought tolerance, retaining moisture, efficient nutrient cycling, increasing organic matter, increasing diversity and increasing soil carbon. In addition, keeping soil covered can help control erosion, protect soil aggregates, cool soil and provide habitats for soil organisms.

In addition to growing cover crops, utilizing no-till practices also can help alleviate soil disturbances and minimize soil losses. Nathan Lowder of the USDA Natural Resources Conservation Service said no-till should be used in conjunction with other soil conservation practices. “Soil must be able to function as a vital living ecosystem including nutrient cycling, as well as water infiltration and availability,” Lowder said. “Soil also must be physically stable and able to support plant growth. No-till cropland can do this if diverse cover crops are grown.” Doug Newton, a farmer in Dillon and Marlboro counties, grows corn, soybeans, wheat and peanuts. He practices no-till and uses cover crops for mulch.

“We had been using no-till on our crops, but didn’t see any real soil health benefits until we started growing cover crops,” Newton said. “Growing cover crops has allowed us to cut our input costs, without lowering our yields. If we can cut costs and stay in business and it’s good for us, we’ll continue to grow cover crops.”

Growing cover crops, along with crop rotations, also is helping control nematodes on Newton’s farm. While reducing tillage may help, Kris Nichols, soil microbiologist with a soil health consulting firm, said using a systems approach which begins with optimizing plant photosynthesis and soil organic matter is most beneficial.

“We need to bank more carbon in the soils,” Nichols said. “To do this, we need to keep a diversity of plants, including cover crops, growing in our soils. Diversifying crops is good for the climate and good for farmers’ wallets.”

In addition, carbon in the form of plant organic matter in the soil is essential food for soil microorganisms that perform many benefits in agriculture including making nutrients in the soil more available to plants. David Kinder is a Royston, Georgia farmer who attended the conference. Kinder grows corn, soybeans and wheat. For diversity, he also raises chickens. Prior to growing row crops and raising chickens, Kinder was a dairy farmer. 

“I’ve learned it’s important to learn about new practices and evolve with the times,” Kinder said. “You need to evolve, or get left behind.”

Written by Jennifer Brodie from REMIN Scotland Ltd

A 5-day FACTS Course at SRUC, Craibstone, Aberdeen confirmed our soil is a mix of 5 ingredients: air, water, decayed organic material, minerals and living organisms. After 15 years working with ancient Scottish basalt, that erupted onto Planet Earth 360 million years ago, before vertebrate life lived on land, I am convinced that it is the interaction of these last 2 ingredients, in the soil, ie minerals and living organisms, that is the key to good health. This is health not only of our soil, but also our plants and animals, ie our food, ourselves and our planet.

As illustrated by Dr Elaine Ingham’s excellent work on the Soil Food Web it is now evident that decades of intensive farming have drastically damaged the life in our soil. The hijacking of agriculture by chemistry over biology has resulted in the loss, or locking up, of our soils minerals and trace elements leaving the soil biology in no fit state to make them biologically available to plants. The McCance and Widdowson paper shows the mineral content of our food crashed drastically from 1940 to 1991. Further exasperated by food processing, this is leaving us overfed and under nourished.

So yes, whilst chemical analysis shows many soils are short of specific minerals and trace elements, I am here to tell you the full quota of 17 are present in REMIN volcanic rock dust – and worms love it! This award winning, organically approved, freshly crushed, finely screened dust is currently sourced from one Scottish Quarry. It shouldn’t be puzzling, but it often is, why the benefits of volcanic rock dust are far more evident when applied to gardens than when applied to farmland. A key farming client is Chris McDonald of Bays Leap Farm, near Newcastle. His application of REMIN was featured in a recent broadcast of Channel 4’s Food Unwrapped when Chris walked the talk with presenter (and pig farmer!) Jimmy Doherty.

The programme included an excellent piece by Sheffield University’s Professor Johnathan Leake where he compared a soil sample from a wood coppice, with the soil in an adjacent cropped field. The difference in soil biology was dramatic with the undisturbed soil in the wood hosting a healthy population of worms whilst the famers field appeared lacking in life. Aristotle told us 350 years ago, worms are the intestines of our soil. As Prof Leake showed in this example, the life in some farmers soil is visually gone. It therefore takes longer to show the dramatic benefits that the gardeners are finding in their less intensively worked and more biologically active soil.

The best farming result I have seen is Warwickshire sheep farmer, Ted Mawby who mixed 4 : 1, by volume, with cow manure resulting in the best pasture Ted has seen in his 24 years of farming. The minerals and microbes in Ted’s mix would appear to be working together to produce exceptional results. Having exhibited at the ace Groundswell in 2018 it was then fabulous to get a 28t bulk REMIN order from John Cherry to mix with his compost windrow. This pile was turned with their new compost turner supplied by BJC Smalley and Co from Berwick and this was demonstrated at Groundswell 2019. Livestock farmer Alex Brewster of Rotmell Farm, in Perthshire has used our products since August 2017. Alex selected one field as a control, applied just REMIN to a second field and REMIN plus cow manure to the third.

When I visited Rotmell, Alex showed me whilst REMIN / FYM application displayed the biggest difference, the benefits of the just REMIN was also evident in the health and the yield of the crop. In Alex’s words “We are clearly onto something and I am particularly keen to follow through on the minerals / microbes aspect of the product.” For 2019 Groundswell I invited Jersey based UK Soil Food Web consultant, Glyn Mitchell of Credible Food to share our stand. We then went straight on to run a minerals and microbes course at the lovely Cabourne Parva Farm in Lincolnshire, that has good conference holding facilities. Here farmer, Peter Kirke, as well as including bulk loads of REMIN in his windrowed farmyard manure, wood chip and silage grass, boosted his compost tea with our product and we look forward to seeing the results.

This August the afore mentioned BJC Smalley took 2 bulk loads. I visited them in September and saw their windrow composting where the REMIN had been added. The photo below was taken by Hughie’s son Michael Leyland, who is a dab hand with the drone camera, of their Windrow mix topped with 2 bulk loads. I have so much more to share including the very topical (and fantastically exciting!) inorganic carbon capture of carbon by freshly crushed rock dust and the organic carbon capture as the soil biology, plant productivity and health increases. We know anywhere in the world with volcanic soil, ie soil close to recent volcanic activity, is exceptionally fertile and productive. With a decade and a half of seeing for myself what REMIN can achieve in gardening soil, all around UK and abroad, all I can say is “Stop havering, and try it for yourself. Just like the gardeners before you, I fully expect you will be back for more!”

Written by David Purdy from John Deere, based on work at Agrovista’s Project Lamport

A project, now in its 7th year, initially developed and managed by industrial partner AGROVISTA to study the cultural control of blackgrass at their flagship Lamport trials site in Northamptonshire used cover crops in conjunction with spring cropping to develop a rotational production system to manage blackgrass populations on heavy soil types. Early observations and successes suggested as well as controlling blackgrass, reducing headcounts from over 500m2 to less than 2m2 for example, the soil also improved as well as maintaining sustainable spring wheat yields. To study these effects further a larger fully replicated trial site has been developed at the same location. The background to the trial focuses and expands on the findings at Lamport along with some of the wider significant challenges and limiting factors on cereal yields and profitability in the UK. These include declining soil organic matter and soil health, soil compaction and obviously grass weed control. After soil organic matter reduction, soil compaction is one of the most damaging factors for plant growth and yield.

As machinery axle weights increase further deeper compaction is inflicted on soils resulting in further subsequent damage. However modern tyre technologies and lighter axle weights can help mitigate the damage. Tillage is used to break up the compaction and restructure soils to enable crop growth and development but often has further damaging effects for example the further loss of soil organic matter with the associated negative effects. Finally, the blackgrass issue has grown out of post emergence herbicide resistance and therefore increasing populations which has made control in winter cropping of cereals more challenging, therefore, spring cereal production systems are often used as a cultural control mechanism to help deal with blackgrass.

The use of cover crops is growing in the UK, however their scientific understanding on the effects on soil health factors, spring cereal crop yields and their part in blackgrass control is limited. This trial using large replicated field trials running from 2018 – 2021 will investigate the effects of low disturbance tillage, different levels of compaction, lower axle weights, modern tyre technologies and cover crops in a spring cereals production system. The overall aim is to understand the combinations of physical treatments with the biological impacts of plant rooting systems of cover crops to improve soil health, ensure resilient yields and control blackgrass in a spring cereal production system, in summary the roots verses iron philosophy, allowing at capture of carbon through photosynthesis to feed the soil food web which in turn delivers gains to soil health.

Two large replicated trials have been established. The first, fully replicated 32 plot experiment, established in 2018 compares the effects of low disturbance tillage at 20cm and zero tillage with the biological effects of cover crop species black oats and phacelia grown both individually and combined.

The second fully replicated 48 plot experiment established in 2019 compares the effects of pre compacting the soil at two different tyre pressures on lower tractor axle weights, low disturbance tillage at two different depths with the biological effects of black oats and phacelia cover crops combined. Along with control plots and replication these trials result in a large 96 (12 metre x 12 metre) plot trial site.  

Their effects will be assessed with range of physical and biological measurements including water infiltration rates, soil structure, bulk density, penetrometer resistance, shear forces, organic matter, worm numbers, decomposition rates, mycorrhizal colonisation and yields among others. Were appropriate precision farming technologies such NDVI and telematics are being employed to measure cover crop biomass and fuel consumption.

The objective is to build a production system that improves soil health and in turn resulting spring cereal yields and well as managing blackgrass to low levels. Early results are showing some positive results including,

• Worms are increasing under cover crops but declining under tillage.

• Soil structure and aggregation are improving under cover crops.

• Spring wheat yields are improving after good cover crop biomass production

• Blackgrass control improves after cover crops

• Combinations of cover crop and low disturbance tillage has yield benefits to subsequent spring cereal yields

Along with specialists from Agrovista the project partners include Philip Wright from Wright solutions and well as various specialist machinery providers. The research forms part of a PhD programme at the University of Nottingham. Project Lamport has open days in July where further details and result will be presented

Written by George Hepburn from QLF Agronomy

I have worked with farmers on their inputs for the last 15 years. I worked with Soil Fertility Services for 12 years as a Soil Fertility Advisor, advising many farmers on soil health and nutrition. For the last two years I have worked for QLF Agronomy (based in the US), advising farmers on the virtues of using carbon in biological and conventional farming contexts to feed the microbes and fungi which has shown significant yield, quality and fertility improvements. I am FACTs qualified and I have Certificate in Nutrition Farming from NTS. I have seen biological farming go from muck and mystery to main stream agriculture but there is still much more for us to understand about the soil and more importantly the life within it.

Whilst working with quality proven carbon-based products for the past few years I have seen the results of extensive trials and farm use to improve the crops in the US, UK and EU. I believe that future of farming is biological not chemical and over the next 10 years using carbon with inputs will become a standard procedure as the environmental factors alone, such as improved efficiencies and efficacies of fertiliser and fungicide, better conversion of residue to OM and improved breakdown of chemical residues (e.g. glyphosate) are going to push farmers and policy makers down this route. At the moment there is not enough trial work done in this area by the big agronomy companies, although it is increasing as more farmers and agronomists are switching on to the benefits of a biological system.

You have probably heard that there are more organisms in a teaspoon of active soil than there are people on the planet, there is a very complicated world of interactions going on beneath our feet, which even the top soil scientists admit we know little about. We do, however, know the difference that soil biology makes when it starts working for you. Soil structure improves, water is held when needed and released when not, availability of nutrients improves, it can handle traffic much better and it smells like rich dark chocolate!

One Teaspoon of Healthy Soil

• 75,000 Bacterial Species

• Metres of Fungal Hyphae

• Thousands of Protozoa

• Hundreds of Nematodes

• A Few Micro-Arthropods

• Billions of Living Creatures!!

Farmers working on direct drilling systems often notice very quickly how their soil does improve (in a soil sense of time) but many still do not look after the life in the soil enough to get the best out of it. You can now buy different strains of bacillus bacteria and mycorrhizal fungi and apply them directly to your soil, I have sold these products to farmers and they have worked sometimes but not consistently, and this is the problem there are so many variables you don’t know which ones are affecting your soil life.

I am now of the opinion that if you look after the soil, and feed it with the right foods then the soil life will follow without applying any of the actual bugs. There are certain situations that I can understand applying them for example after potatoes when large amounts of chemicals have been applied alongside a major cultivation program, but most of the time what you actually have to do to get these microbes working for you is quite simple.

Ideally you are looking for the target ratio of 45% mineral, 5% OM, 25% air and 25% water. This is the home that the microbes need to not only live but to thrive in. Microbes will respond to feeding by an increase in number, but you will never get to the optimum levels unless they have the correct surroundings. Air and water in the right ratio is key for stimulating the biology. The best way to check this is with a spade and your senses. Dig in a number of places across the field and feel at how well the spade goes in, how far the roots go down, the smell, number of earthworms (and other visible soil life) and how well residue is breaking down. If you want a point of reference go to an old hedge and dig underneath it. This is the potential of your soil.

Science can help too. Calcium and Magnesium help to define the structure of your soil. High magnesium levels can make the soil quite tight and sticky, not allowing air in and holding on to water. High calcium levels can mean the soil is too open and can’t hold on to water or nutrients. Neither of these situations are good for the soil microbes. This is where an in-depth soil test can be useful looking at the exchangeable nutrients and certain key ratios like Ca:Mg, which can guide you down a soil remediation route. When you have the correct soil structure; which I am seeing more frequently as increasing numbers of farmers do less and less tillage, the next job is to feed the soil or more importantly the microbes and fungi. FYM, compost, lime, cover crops, green manures and digestate are good ‘fertilisers’ as they are all giving the soil life a job to do, but to help them to achieve this they need some energy. Plants do with this by exuding simple sugars, fatty acids and enzymes out through the roots to feed the microbes and we can mimic this by applying similar substances to the soil.

Using a carbon-based (read sugar) product like L-CFB BOOST™ as part of your system can make a big difference, not only are there various types of sugar (sucrose, fructose, glucose and more) which is ideal for feeding the bacteria there is also a more complex food added for both microbes the fungi. Using this type of product alongside your regular applications means that every time you go through the crop you are looking after and feeding these microbes and helping them to perform their role. Do be aware that there are many types of these carbon products getting on the market going from raw beet molasses through to humic acids. Some of these are not suitable for this type of application and a lack of consistent trial data over the years puts a question mark over their benefits. Make sure you ask for independent and farm trial data and look for a good track record of results and ideally farmers that are using it that you can actually talk to.

Getting your soil microbes working for you can mean reduced inputs of fertiliser and fungicides, OM levels building, less run off and erosion, better water holding capacity, improved rooting, better residue breakdown and increased nutrient cycling. All you have to do is give them a stable home and feed them with a quality product little and often.

Written by Jerry Alford from the Soil Association

There has recently been a lot of interest in the potential of organic no-till and it has been described by some as the holy grail of organic arable farming. It is also something that is of interest to non-organic farms because of the potential to reduce inputs, particularly on less profitable break crops.

Organic arable farming systems have always been built around the use of cover crops, diverse rotations and animals. Building fertility during the rotation for high value crops and also using these covercrops and grass leys as part of weed control strategies. These regenerative phases have always been used to counter the effects of the exploitative phases where crops and tillage remove soil nutrients. Organic regulations (EU Regulations 834/2007, 889/2008 and 1235/2008) prohibit the use of artificial chemicals and fertilisers and support the minimisation of the use of non-renewable resources and off-farm inputs. Put simply, the requirement is for circular economy principles to be followed as far as possible. Many organic farms include grazing livestock enterprises and as with non-organic mixed farms, soil health will benefit. In stockless organic arable systems, clover is grown as part of the rotation and is regularly topped and mulched to build soil fertility.

It is difficult to compare an organic arable farm with a non-organic arable farm because rotations, inputs and even crops may vary. Most organic rotations include legumes because of the fertility value, but very few grow oil seed rape because of its high nutrient demand and pest risk, to both it and following crops. The inclusion of fertility building phases in the rotation is also very different, although this is becoming more widespread in nonorganic systems. Cover crops over winter as green manures are also often part of the rotation. Organic farms can use composts, manures and digestate, subject to certain restrictions, but there are no synthetic nitrogen products approved.

The biggest problem organic farmers face is weeds, particularly grass weeds. Blackgrass can be a problem but the diverse rotations including ploughing, spring cropping and low fertiliser use does seem to reduce its effects in organic systems. In non-blackgrass areas, other weed grasses like annual meadow grass and bromes can reduce yields if allowed to develop. Perennial grass weeds like couch are also a problem although an Innovative Farmers trial has shown positive effects by using buckwheat which has an allelopathic effect as well as a shading effect when the weeds are at their weakest after harvest. Ploughing has become the main weed control mechanism for many organic farmers, with seedbed preparation and cultivations being part of the weed control strategy. However, many organic farmers have looked at using min-till or non-inversion techniques through their rotations to reduce the need to plough. Most would plough 3 times during a 5-6year rotation but finding a way to grow organic crops using a no-till system during the rotation would be a good next step.

The benefits and potential of Conservation Agriculture are plain, but an organic farmer is restricted by the need to generate fertility on farm, the decision not to use chemicals and their customers choosing to buy organically certified products. The Soil Association agrees with the principles of conservation agriculture and in the long term would hope to get to a situation where tillage in organic could be reduced still further and conservation agriculture could take place with reduced or zero herbicide use. Knowing what the issue is the easy bit, finding the answer is the challenge.

So how do we get there?

If we are going to go no-till organically we need to control weeds and cover crops without chemicals. There are already three practices used worldwide, which have been tried in the UK by organic farmers, with varying degrees of success. None have been tried organically into long-term no-till situations.

The most well-known is the crimper roller. Developed by the Rodale institute in America, the ribbed roller crushes the stem of plants. The rolled plants then act as a weed controlling and moisture retaining mulch which also returns nutrients and organic matter into the soil. To work properly the crop being rolled must be an annual and at anthesis (early flowering). In America the most common crop crimped is rye which is at the correct stage when Soya and Maize are being drilled. In the UK the correct growth stage comes too late for UK cropping. The allelopathic effects of the rye may also make it unsuitable for small seeds like wheat. In an organic rotation, there is the potential to grow rye as a cover crop and then crimp and drill vetches during the fertility building phase. This second cover can then be crimped and will supply nitrogen to an autumn drilled cereal. This avoids the need to plough out a grass ley which itself can become a source of weeds.

The second technique is to drill a crop in the winter into a frost susceptible cover crop such as buck wheat, berseem clover, phacelia and mustard. This will provide a mulch to the next crop as well as nutrient recycling. Smaller seeded plants may not work in this situation because they are less competitive as seedlings, but it has been used for beans. There is a potential problem if there is a mild winter because any cover crop plants which produce seed could create a weed problem in later crops so some form of management may be necessary. Grazing with livestock could be an option because cereal and OSR plants will regrow after grazing. As part of an Innovative Farmers trial on alternatives to glyphosate a group of farmers used rollers on cover crops during a frost to investigate whether they would be an option and did show some success, which would allow late winter drilling where ground conditions allow. 

A third option is to use a permanent understorey and drill into this. Similar to pasture cropping which drills into permanent pasture this form of bicropping would use a clover understorey to provide both cover and fertility to the growing crop. This technique has been used in non-organic situations where the clover is either grazed hard or sprayed with glyphosate at low rate and crops drilled into this. Clover needs soil temperatures of above 10 degrees to grow and so is not very competitive against a winter/early spring sown crop but could be an issue at harvest if the crop is not competitive. It is important to choose a smaller leaved and low growing variety of clover. Nitrogen will be released when the clover is cut and so some method of topping or crimping between rows would release nitrogen to the crop. After harvest the clover could be mulched, cut for silage or grazed prior to the field being redrilled in the autumn/winter. In theory any crop which is competitive could be drilled into this permanent cover which will self-seed and spread to maintain a competitive mulch. Possible problems come during later years if the clover grows too quickly or competes for moisture with the germinating crop plants.

Innovative Farmers are setting up a trial looking at this using white clover as a cover. To be held on long-term no-till farms and an organic farm, the plan is to plant a white clover cover crop in the summer after harvest and drill a spring crop for 2020 harvest. This can then be continued into 2021 and there is the possibly to also look at techniques to manage nitrogen release from the clover. If this proves effective it could be possible to have a rotation including cash crops every year with a permanent cover crop in the understorey.

Trying to fit these techniques into either organic or non-organic systems in the UK is tricky. Our maritime climate suits grass and weed growth, particularly during the summer and the current variable weather patterns lead to late weed flushes. If we had European type weather patterns with dry summers and hard winter frosts, it would be easier to do. As a result, we need to look at what cover crops and cash crop rotations fit best into the UK climate and farming systems. This research must also look at profitability and costs of systems as much as at inputs and this research needs to be done at both farm and regional level to move away from a one size fits all scenario. Both organic and non-organic farms would benefit from sharing this knowledge and applying those practices which they can borrow from each other or which can be adapted to fit.

Please contract the Soil Association on 0300 330 0100 for more information or advice.