Ensuring the right amount of nutrients are supplied, in the right quantities, to the dairy cow is a key day-to-day consideration for most dairy farmers. However, this month, British Dairying, explores the view of a group of farmers who are encouraging producers to feed soils with equal, or even greater, importance than the cow.
“When you’re feeding the cow, you’re feeding the rumen microbes, the same principle applies to feeding the soil, it’s the soil microbes that need feeding,” explains dairy farmer Wil Armitage.
“The cow is always right,” says Wil. “If her nutritional demands aren’t met you’ll know about it.” He adds that the same thinking should be applied to soils. “The soils are always right. If you’re not achieving the quantity or quality of outputs you’re expecting – or relying excessively on inputs – I’d encourage you to turn your focus to the soil.”
Speaking at QLF’s Soils Event in Staffordshire, alongside biological farming champion Gary Zimmer, Wil explains how his conversion to organic farming in 2005 led him to consider biological farming practices.
“The introduction of biological farming wasn’t so much about what we were doing, it was more about what we stopped doing. In a broad principle it was a switch from chemistry to biology.
“We had to get our soils working better, but they wouldn’t work without biology,” says Wil, who farms over 3,000 acres.
“Our first change was to stop applying nitrogen. Soil biology will struggle to survive in highly soluble nitrogen soils. We also changed our cropping to introduce more diverse species to our swards to encourage deeper root penetration, and introduced cover cropping.
“However, following the implementation of some basic biological farming principles we noticed that despite our soil health improving, and initial year-on-year increases in yields, our outputs eventually plateaued.”
Nuffield Farming Scholarship
“At this point I questioned our future in organics due to viability, so I embarked on a Nuffield Scholarship, it was on this study journey I met Gary Zimmer and realised there was a lot more we could be doing,” says Wil.
“With a better understanding of soil biology and a focus on the diversity of soils and cropping plans, I realised that we have a real opportunity to improve the integrity of the food we produce and have a positive impact on animal and human health.”
Wil completed his Nuffield Scholarship, titled: ‘Sustainable Milk Production: the vital role of Soil for Feed Integrity’ in 2014 and since that point he’s implemented his learnings across his enterprises.
“Following the implementation of various practices since my scholarship, such as base saturation soil analysis and the application of liquid carbon-based fertilisers, we’ve not only seen plant health improve but also animal health,” adds Wil.
“Annually we have 4 to 5 cases of mastitis per 100 cows, and we’re also now providing cows with bio-available minerals from our home-grown feeds.
“We’re also growing 28t/acre of fodder beet organically and our silage yields are comparable to conventional farms at 14t/DM/ha.”
Carbon to nitrogen ratio
Wil adds that with 74,000t of nitrogen available in the air above every hectare he focuses on making the most of available natural resources.
However, he adds that most nutrients are not immediately available to plants, and therefore need be broken down by soil life.
“The higher the soil biology, the more mineralisation occurs,” says Wil. “Soil biology creates the vital links between the minerals in our soils, the plants and the animals; and ultimately the nutrient density of our food.”
Wil adds that the oversupply of highly soluble fertilisers is shutting down soil biology and is burning carbon reserves causing imbalances in soils.
“Producers shouldn’t see nitrogen as a limiting factor in crop performance. The limiting factor is often carbon.”
Wil explains that the key to improving soil health is getting an optimal carbon to nitrogen ratio. The soil microbes need a balance of carbon and nitrogen, the same as a cow’s rumen needs a balanced diet to optimise health and performance.
“Soil microbes can range from one-part nitrogen to five parts carbon, and up to one-part nitrogen and 30 parts carbon. So highly fertilised soils, without sufficient carbon sources, can present an extremely challenging environment.
“I’ve found that adding complex sources of carbon to the soil stimulates the activity and growth of soil microbes and ultimately plant growth and integrity,” says Wil.
He explains how he applies an organic approved liquid carbon-based fertiliser to his crops. “Terra Fed, from QLF agronomy, is a source of carbon and plant nutrients.
“It contains molasses, which just like providing energy for the rumen microbes, provides energy for the soil microbes.”
Macro nutrients
Gary Zimmer, manages over one million hectares under his biological farming consultancy company, in Wisconsin and Upper Midwest USA, and he uses liquid carbon-based fertilisers routinely.
“Livestock farmers have the opportunity to increase soil microbes by using farmyard manure and compost, as well as carbon-based liquid fertiliser, as part of their fertiliser programmes.”
“By increasing soil biology, we can encourage stronger mineral transfer from soil to the plant which will ultimately produce a better-quality feed crop,” says Gary
He encourages farmers to move away from thinking about just NPK as a measure of soil and plant health and to instead monitor the macro nutrients by reviewing base saturation levels, particularly paying attention to calcium and trace elements.
“Calcium is vital for any plant, as is magnesium, phosphorus and boron.
“Calcium is needed for both soil and plant health and boron works in synergy with calcium. When calcium levels are in balance plants can absorb more nutrients.
“However, these minerals require a complete biological system to get them up to the desired level, and therefore farmers should be looking at the whole soil health picture rather than focusing on one aspect,” explains Gary.
Wil agrees that farmers can increase outputs and significantly improve crop health by selecting quality balanced inputs including micronutrients.
“On farm we have the opportunity to greatly increase the quality of the feed we produce but to achieve this we must first establish the correct micro and macro nutrients in the soil.”
Soil organic matter
Wil also adds that soil organic matter is essential for soil function. “For every one percent increase in soil organic matter, an acre can hold an additional 20,000 gallons of water. Soil microbes have a crucial role to play in converting crop residues to organic matter.”
Although soil types and organic matter formation vary from field-to-field, if the diversity of soil microorganisms are supported by correct biological practises this will help to build soil organic matter.
“Rotation and cover cropping play a huge role in developing organic matter, as well as promoting soil biology.
“In addition, farmers can take action to minimise losses to leaching and erosion through reduced tillage, and keeping a tight rotation when growing forage crops. As livestock farmers, we should be utilising organic manures,” adds Wil.
Stepping into biological farming
Wil advises those who are interested in biological farming to look at the bigger picture and find out the strengths and weaknesses of their soils.
“Farmers need to think about what they’re aiming for and if there’s a desire to reduce inputs and increase yields then changes will need to be made.
“Biological farming offers farmers the opportunity to bring efficiencies back on farm and although you can’t change soils over-night, I would urge others to adopt a fertiliser policy to address the limitations of soils,” says Wil.
He adds that ultimately biological farming is all about achieving the best possible soil, to grow the most nutrient rich crops, to feed healthy livestock which produce nutrient rich outputs.