While many farmers are sceptical about biological farming, Pietermaritzburg professional natural scientist Howard Alborough believes that one day this method will be accepted as the way to go. “There are two extremes in farming,” says Howard. “The one is the 20th century approach where the over-use of chemical fertilisers and control agents, as well as long-term monocropping, has depleted the soil of organic material and microorganisms.
The other is organic farming which, in a sense, is an overreaction to the 20th century approach. I believe the answer rests somewhere in between, using organic principles in conjunction with the minimum use of chemicals.” A lso referred to as reduced chemical farming, biological farming is all about growing crops by using as few herbicides, pesticides, chemical fertilisers and fungicides as possible, while maintaining and in most cases increasing yield and farm profit.
It also reduces erosion and leaching, and decreases insect, weed and disease pressure. Building a foundation The basis of biological farming is to create healthier soil by replenishing organic matter and beneficial soil microorganisms. robust soil foodweb with millions of oxygen-loving microorganisms per gram of soil is needed to achieve soil balance and health. “One teaspoon of organically rich soil can host 600 million to 1 billion organisms,” says Howard. “These may be comprised of 15 000 species. In comparison, soils that have been abused and have little organic material, may contain as few as 100 bacteria, and very little else.”
Research by the Danish Institute of Agricultural Sciences and Newcastle University in Australia has found that by increasing the soil humus content and carbon levels, food produced has a higher nutritional content than conventionally grown produce, and livestock are healthier. Converting to biological farming is a three-year process and acts as a consultant to farmers through his business, Growit Trading. In the first year, fertiliser applications are reduced by about 15%, based on a soil analysis, followed by a 20% to 25% fertiliser reduction in the second year and a 30% or more reduction in the third year.
Bigger root mass in sugarcane The first step of any programme is to get the organic material back into the soil. One way of doing this is by increasing root mass. Howard is running trials with the SA Sugar Association to increase sugarcane root mass. “When cane is harvested, most of the root mass dies back, typically leaving about 30t of root material per hectare,” says Howard. “We then apply products containing the right mix of bacteria, fungus and herbal extracts, and this can push root growth and increase root mass to up to 90t/ha, three times the original size. All that mass is then decomposed into the soil.
That means the farmer has about 60t/ha of compost he didn’t have before he cut the cane.” Bigger root mass also improves plant health. “By creating a bigger root structure, which in many plants has extensive webs of mycorrhizal fungi attached to it, the plant can access more nutrients and water in the soil, and it grows faster,” explains Howard. “Cell formation and structure is improved, which in turn means that viruses and fungi find it more difficult to penetrate the plant, so, lodging is reduced.
Further, water stress is reduced and there is improved tolerance to frost.” Increased organic matter also loosens up the structure of soil, resulting in better moisture retention, less water runoff and reduced fuel consumption and wear-and-tear on machinery used to work the soil. Howard’s methods are usually combined with a minimum-till system, designed to reduce disruption of the soil ecology. Accelerated composting Another way a farmer can increase soil organic matter is by incorporating organic material such as chicken litter, pig and cow slurry, woodchips, cane tops or residual crop material into the soil. While transporting this material from a 50km radius is viable, the most cost-effective option is to use residual crop material and left-over root mass that is already being produced on the farm.
By adding products that contain enriching microorganisms to the soil, organic content is biologically enhanced. While traditional organic enrichment methods can take nine to 12 months to break down sufficiently for on-field application, Howard can speed up the process to anywhere between 30 and 75 days. “This is achieved by applying biological inoculum that contain high numbers of specific, naturally occurring microorganisms,” he explains.
“If we can produce 10 000kg of compost in 30 to 40 days, rather than a year, it reduces the costs, such as the cost of equipment, the labour needed to turn it, and the space.” The biological inoculum also retains nitrogen and ammonia and reduces pathogens, which ensures a healthy production environment – an important consideration when one is dealing with slurry. “Slurry loses up to 75% of available nitrogen and if it is not applied correctly, if can do more damage than good to the soil,” stresses Howard.
“Soil is an aerobic environment and its microorganisms require a lot of oxygen. Slurry is typically an anaerobic environment with anaerobic organisms. If you pump slurry onto soil, the two sets of organisms go to war at a microscopic level.” Slurry application also requires between three months and a year before soil health starts improving. “The soil first has to recover,” says Howard. “But by simply adding products that contain beneficial soil organisms before it’s pumped onto the field, slurry can be turned into readily available organic fertiliser.”
New biological products Products that go hand-in-hand with biological farming are still relatively new in SA. “They have been on the overseas market for about 10 to 15 years and locally for only about five years,” explains Howard. “This field is developing all the time and in the last three to four years, local manufacturers have been producing local equivalents although their technology is lagging slightly. New technology has taken a lot of the complication out of the application of the products to the soil and the programmes are relatively simple to follow.” More advanced products also have built-in disease control.
“This is achieved by controlling soil pathogens and improving the immunity of the plant through a homeopathic-like approach such as using plant antibodies to make the plant more tolerant to disease.” Howard explains that a relatively inexpensive biological programme corrects soil balance and can, in some cases, double crop yield. “South African farmers are still sceptical, but trials have shown that biological farming can increase yield from about 80t to 200t/ha,” says Howard. “Farmers typically produce 10% to 15% more yield using 50% or less fertiliser. IIIn India reports indicate massive increases in cane yield from about 80t/ha to 250t/ha.”
According to Howard there are also reports that because plant cell structure is improved, fruit lasts two to three weeks longer on the shelf and trees hold fruit better during drought as the bigger root systems can access more water. Contact Howard Alborough on 072 210 4292 or e-mail [email protected] |fw
