Yield and quality can be improved, within the existing fertilizer budget, by a move to Biological Farming.
Soil and tissue testing are essential to assess the available nutrition in the soil and allow the farmer to devise an effective fertility strategy that boosts both yield and quality, explains Gary Zimmer of Midwestern Bio-Ag, the keynote speaker at Agri-Tech East’s REAP conference on 9 November. Zimmer is a pioneer of biological farming, which places great emphasis on the role of microorganisms and balanced nutrients in maintaining plant health.
Biological farming is not the same as organic farming, and Zimmer advocates the addition of appropriate minerals to the soil:
“After many years of looking at tissue and feed tests, I saw a link between crop health and the ‘big four’ of magnesium, phosphorous, calcium and boron. Plants that test high for these minerals are always high yielding regardless of the crop. Where crops are prone to disease these four minerals are always low in the soil, and when these minerals are added the benefits are seen in the feed tests.
“However for nutrients to be converted into a form that plant roots can absorb, there must be sufficient bacteria, fungi and other soil life present,” Zimmer says. “If soil is fed a balance of minerals and enough organic matter to keep the soil life functioning the benefits are wide ranging.”
Role of microbes
Zimmer, who was trained as a dairy nutritionist and has a family dairy farm, compares the soil microbes to role of the microbes in a cow’s rumen and says that by understanding the parallels he was able to make the breakthrough that led to development of his ‘Six Rules of Biological Farming’.
“By working with biological systems it is possible to grow healthier disease resistant crops and reduce over-dependence on chemicals and fast-fixes. Returning to a more natural system will make farming sustainable for the long haul.”
Zimmer advises fellow farmers on a wide range of strategies from tillage, to balanced fertilizers , cover crops , along with compost and manures. The results have been significant, with yields increasing by over 50 per cent with reduced inputs.
He says: “Farmers can’t do anything about the weather but they can grow plants with bigger root systems that are more drought tolerant. You can’t change the soil but you can grow cover crops, add manure, and use balanced fertilizers and thoughtful tillage to improve the soil. You can’t lengthen the growing season but you can alter the rotation to add diversity.
Talking to UK farmers
Julius Joel (pictured right), of Spearhead International and chair of Agri-Tech East’s stakeholder group, has been out to Zimmer’s farm to see for himself. He says: “The difference in the crops grown by biological farming principles is visible in the field and quantifiable in the yields. Of particular interest to me is the work that Gary is doing on improving the nutritional content of the grain through carefully formulated fertilizers and working with the soil.”
Joel took Zimmer out to farms across the East of England to share best practice during Agri-Tech Week, a week of events in November designed to showcase excellence in innovation across the agri-tech value chain.
Zimmer explains that just because nutrients are added to the soil there is no guarantee they will reach the plant.
Soil life is essential for converting nutrients into a plant-available form. For example the fungi Mycorrhizae forms a network around the roots to capture water and nutrients, such as zinc, phosphorus and copper and bring them to the plant. Beneficial fungi also provide protection from pathogens.
He says: “Mineral analysis of feeds, stems and leaves, is a way to check if your fertility program. To make sure the plant is accessing needed nutrients.”
He also stresses that tissue testing should be done at different growth stages on healthy plants as this gives a good picture of the nutrients the plant is able to access. Of particular importance is calcium, which increases the bioavailability of other nutrients and is essential to cell membranes. It is also used as a messenger, allowing plants to respond to stressors like heat, cold and drought.
Correctives and fertilizers
Zimmer makes the distinction between soil correctives – used to fix the soil and reduce the limiting factors – and crop fertilizers, which are applied each year to feed the crop.
He explains that cover crops and green manures can also be considered soil correctives and provide a valuable role in improving the health and resilience of the soil. He says: “The choice of cover crop will vary according to farm preferences and the area where you farm but they are invaluable in breaking pest cycles, improving water infiltration, suppressing weeds, reducing run-off and protecting soil life from extremes of hot and cold.”
He continues: “It is more important to stay within your fertilizer budget and work towards a goal of balanced soil than to fix everything right now.”
The form in which nutrients are delivered is important, it’s not always the cheapest per unit and he considers mined minerals, which contain other trace minerals, better for the soil life. He also draws an analogy between soluble fertilizer and sugar: too large a dose can cause health problems but sufficient at the right time is beneficial. “Many farmers apply all their fertilizer for the season in the spring when the crop is not yet ready to use the nutrients; incorporating a slow release fertilizer will maintain nutrient levels for longer and reduces run-off.”
“This is why I recommend a balanced fertilizer, including trace minerals, and a plan for getting them into the plants that includes other elements of cultivation.
The Six Rules of Biological Farming
This is captured in the Six Rules of Biological Farming:
- Test and correct your soils
- Use a balance of fertilizers that do least damage to soil life
- Use pest control and nitrogen only when absolutely necessary
- Create plant diversity with tight rotations and cover crops
- Use tillage to control soil air and water and decay of organic materials
- Feed the soil life using carbon from manures and calcium from a good source
“The farming methods we have been using have got us this far, but at a cost to our environment and health; the future must be different. It is now time for ‘brains, balance and biology’ – we have a lot of mouths to feed and only one Earth to take care of. We need to help the Earth take care of us all.”
Gary Zimmer gave the keynote address at Agri-Tech East’s REAP conference on 9 November 2016 at the Wellcome Genome Campus Conference Centre as part of Agri-Tech Week.