There is also a case study at the end of this article proving how one farmer benefitted from using vermicast.
Consider the following; Vermicast has been around since the start of time, it is not manmade and it occurs naturally in healthy soil ecosystems. If you dig into the forest floor in the Knysna indigenous forests, you will find earthworms processing the fallen organic material. Consider the health and size of the centuries old trees around you that thrive there without any fertiliser or irrigation from man.
Vermicast is a thick black natural compound produced by earthworms. It is a fundamental part of natures soil building process. Vermicast harbours all the components necessary to build and develop soil into a physically, chemically and biologically healthy growing medium for plants to thrive.
Vermicast repairs soil structure to significantly reduce irrigation requirements & associated costs. This means that when using vermicast, you will need less water. It stabilises moisture levels within soil so that the water doesn’t completely run through in sandy soils or become waterlogged and rot roots or seeds in clay soils. With stabile moisture levels in the soil, moisture is always available consistantly to the roots which reduces plant stress.
Vermicast reseeds plant beneficial bacteria, which is the crucial gateway between soil and plant roots. This means that vermicast helps roots absorb what they need from the soil. Worm castings release minerals held within mineral sand for plant availability and repair the structure of soil, reducing soil erosion risks. When you have worm castings in your soil, the microbes in the castings ensure efficicient uptake of fertiliser additions.
Increased plant beneficial bacteria cultures increase the effective uptake and stabilisation within the soil of added organic fertiliser. Peaks and troughs in availability leads to plant stress. This means that when plants are exposed to dips and highs of nutrient and moisture availability, they can become more stressed as opposed to a more constant and flatlined availability.
Reduced plant stress means stronger, healthier, more pest resistant plants, producing greater yields.
Vermicast boosts the pest resistant enzyme production in plants repelling insect attack and fungal infection. Plant growth stimulants and hormones in vermicast encourage both the top growth above the soil, containing the leaf, stem and flower, and the root growth beneath the ground.
Vermicast is particularly effective during seed germination and reduces transplant shock. Vermicast’s beneficial microbes triggers the development of a healthy natural soil-food-web. It seeds and attracts earthworms and other good life into the soil; in turn aerating and conveying microbes and other plant beneficial hormones and plant growth stimulants.
Vermicast also increases the cationic exchange rate. This is the rate at which the cationic soil trace elements can attach themselves to vermicast. Everything in nature has an electrical charge. Some charges are positive (cations) and some are negative (anions). Organic vegetative matter is anionic and, as vermicast is highly concentrated vegetative matter, it is strongly anionic. Most trace elements are cationic, and thus attracted to vermicast. In simple terms this means that trace elements are attracted to vermicast and readily bond to it in the same way that opposite poles of a magnet attract each other. Plants have a stronger pull than the vermicast and therefore draw the trace elements away from the vermicast and into their roots in a natural exchange system.
You can buy worm castings from us or you can make your own worm farm and harvest your very own worm castings. We published a DIY worm farm last year in October and you can find the article here to make your very own worm farm that you can keep in kitchen.
Various scientific trials & studies by a number of Universities (Cornell, Griffith &
Stellenbosch) on a variety of crops have resulted in the same base conclusion; vermicast (worm castings) are highly beneficial to plant growth, health and yield. Vermicast is a totally natural and organic product created by earthworms.
Joshi and Kelkar (1952) reported that earthworm casts contained greater percentage of finer fractions like silt and clay than in the surrounding soils. This change in mechanical composition of soil was probably due to the grinding action of earthworm gizzard. The chemical analysis of Vermicasts revealed that they were richer in soluble salts, neutral or alkaline in reaction and had higher percentage of exchangeable Na, K and Mg but a lower exchangeable Ca than in corresponding soil.
Earthworm casts also contained greater amounts of Nitrogen (N), Phosphorous (P) and Potassium (K). The Vermicasts contained higher amounts of nitrate nitrogen and possessed a greater nitrifying power than the corresponding soils. Vermicast also contained Mg, Ca, Fe, B, Mo and Zn in addition to some of the plant growth promoters and beneficial microflora. Several valuable compounds were also produced through the earthworm – microfloral interaction, which included vitamins such as B12 and plant growth hormones such as gibberellins.
The microbial composition changes qualitatively and quantitatively during passage through the earthworm intestine (Pedersen & Hendriksen, 1993)
Vermicast is coated with mucopolysaccharides and enriched with nutrients. The cellulolytic, nitrifying and nitrogen fixing microbes are found established in the worm cast (Kale et al., 1988). Earthworms directly cycle the nitrogen by excretion in the casts, urine and mucoprotein and through the turnover of earthworm tissues (Lee, 1985) Barois et al., (1987) observed an activation of N mineralization, with the casts having 270 percent more ammonia than the bulk soil. Within a year of application of vermiculture technology to the saline soil, 37 percent more N, 67 percent more P2O5 and 10 percent more K2O were recorded as compared to chemical fertilizer (Phule, 1993).
Atiyeh at al (2002) conducted an extensive review. The authors stated that: “These investigations have demonstrated consistently that vermicomposted organic wastes have beneficial effects on plant growth independent of nutritional transformations and availability. Whether they are used as soil additives or as components of horticultural soil less media, vermicomposts have consistently improved seed germination, enhanced seedling growth and development, and increased plant productivity much more than would be possible from the mere conversion of mineral nutrients into more plantavailable forms.”
Atiyeh et al. (2000) found that compost was higher in ammonium, while Vermicompost tended to be higher in nitrates, which is the more plant- available form of nitrogen. Vermicast’s are excellent media for harbouring N-fixing bacteria (Bhole, 1992).
Earthworms have multiple, interactive effects on rates and patterns of nitrogen mineralization and immobilisation in natural and managed ecosystems (Edwards and Lofty, 1977; Lee, 1983; Lavelle and Martin, 1992; Blair et al., 1995).
Earthworms reject significant amounts of nutrients in their casts. In part these losses result from the intense microbial activity in their gut, and from their own metabolic activity. E.g. The elimination of N due to fast turnover of this element in microbial biomass. A significant proportion of C assimilated by earthworms is secreted as intestinal and cutaneous mucus with greater C:N ratios than those of the resource used (Lavelle et al., 1983; Cortez and Bouche, 1987).
Atiyeh et al further speculate that the growth responses observed may be due to hormone-like activity associated with the high levels of humic acids and humates in vermicast: “…there seems a strong possibility that …plant-growth regulators which are relatively transient may become adsorbed on to humates and act in conjunction with them to influence plant growth”.
Apple Farming at Clan Leslie, Harrismith, Free State
Farmers Weekly 21 October 2010 – Hayden Green
By incorporating vermicomposting and worm-casting tea in its apple production system, Clan Leslie Estate has improved its fruit quality, reduced input costs and improved the soil and tree health in its orchards. Hayden Green visited Mike Leslie to find out more. Mike Leslie farms in partnership with his father Nick and brother Graham on the Clan Leslie Estate near Harrismith in the Free State. Mike’s farming philosophy is to keep things simple, but pay attention to detail. He’s passionate about apple production and about where sustainability is taking the enterprise. He combines technology with applicable management and biological farming techniques to produce fruit that looks good, is healthy and nutritious, and exceeds export quality requirements. To achieve quality and production goals, Mike also partners with nature’s prime recycler – the humble earthworm.
Vermiculture – earthworm farming To branch out into exports, Clan Leslie established its apple production division in 1996. Five years ago, they decided to integrate vermiculture into the operation because of changing export regulations, specifically for chemical residue levels. “Our list of suitable chemicals was and still is shrinking due to global regulations and the green
movement,” Mike says. “Consumers are looking for residue-free fruit, and we had to find a different way of doing things.” Fruit destined for export is batch-tested five days before picking, and Mike felt that moving to natural pest and disease control in the form of “worm tea” would minimise the risk of residue on the fruit, increase its nutritional value, and reduce chemical use and withholding periods. He contacted private consultant Hennie Eksteen for advice on vermiculture, and partnered with vermiculture specialist Poerie Coetzee to manage it. This left Mike himself free to concentrate on orchard management.
“I was initially concerned that salmonella and E. coli contamination from feedlot manure and chicken litter we used as compost base came through in the testing,” he admits. “But we tried the worm tea in selected apple blocks and the results were perfect. The earthworms destroyed all pathogens in the manure, giving us the confidence to freely use compost tea.”
Foliar and soil-feed teas “Foliar-feed tea requires an anaerobic process,” explains Mike. “We mix the earthworm castings with water, molasses, ground Lucerne and fishmeal, and brew the mixture in 1 000â vats for three weeks. When it’s ready, we dilute the tea with water and use it as a foliar feed, sprayed at 80â/ha.” Likewise, converting the solid material in worm castings into a liquid enables a practical, accurate and uniform application of soil-feed
tea throughout the orchard. Soil-feed tea is made aerobically by pumping a large volume of air through it for up to 24 hours. Once the correct microbe population is reached (established by microscopic examination), the tea must be applied undiluted at 200â/ha within a few hours before the aerobic bacteria die from a lack of oxygen. Follow-up irrigation further washes the tea into the soil. The total cost of foliar and soil-feed tea production and application is around R12 625/ha per season. This will decline in time as the orchard health improves and less spraying is needed. Mulching – retaining a natural balance
“In nature, fruiting trees are part of a complicated ecological system, existing in symbiotic relationships with the fauna and other flora to sustain a healthy fruiting cycle,” says Mike. He’s concerned about the consequences and economic sustainability of a system of constant harvesting, with synthetic chemicals as the only inputs. So, mimicking nature, he scatters tree pruning clippings and other plant residue around the base of the trees to eventually decompose and form mulch. “We use nine 1,5mdiameter round bales of wheat residue to every 200m of tree row,” he explains. “This equates to 104 bales, or 26t of dry plant material, per hectare, and lasts for three to four years. Nothing is wasted.” The mulch, besides retaining moisture, feeds the bacterial processes stimulated by the soil-feed worm tea. Mike points to the contrast between mineral soil and the rich organic matter resulting from earthworm activity. “The earthworms manage the environment for me,” he says. “The soil is moving towards a natural state of balance (homeostasis) without chemical fertiliser.” He estimates that this production system needs one-third less irrigation water. “The savings are significant.” Mike was astonished when he first saw the increase in root growth as a result of the mulch and soil feed. “This increased nutrient uptake has resulted in healthier, stronger apple trees.” A competitive advantage “Quality counts. The market is prepared to pay for an apple that tastes better and, more importantly, lasts longer,” says Mike. Mulching with worm tea had precisely this effect, increasing demand for Clan Leslie apples from clients in Africa, where the cold supply chain isn’t as advanced as other export markets. “The local informal market is massive, and is prepared to pay premium prices for quality fruit that will last,” he explains. Although being situated in the south-eastern Free State gives Clan Leslie a three-week harvesting advantage over its Cape competitors, the unseasonal heavy frosts are a problem. Mike warns that worm tea is no silver bullet, and that balancing the soil is a slow process. Over the last five years, he has recorded an average increase from 8 Brix to 12 Brix in his plants, correlating directly to frost resilience. An SMS early warning system notifies him to irrigate when air temperature drops below 5°C.
Incorporating earthworms has increased yields from 50t/ha to 75t/ha in Pink Lady apples, and by 15t/ha in other varieties. The path towards more sustainable production on the 66ha apple orchard constantly challenges Mike. “In the future I would define myself increasingly as a carbon farmer who produces apples,” he says. Based on the success of the worm tea in the orchards, he aims to produce low-carbon-footprint apples with a superior nutritional value. Worm tea has been so successful in the apple orchards that he intends to expand it to the other Clan Leslie enterprises.
Contact Mike Leslie on 082 770 0306 or e-mail email@example.com.