down to earth: Bio-inoculation
Bio-inoculation
The old adage “healthy soil, healthy plants, healthy animals” is more of a truth. We rely on the soil to provide the necessary nutrients to make plants grow. Nowadays we understand better how soil organisms play a vital role in facilitating nutrient exchange, recycling organic matter, improving soil structure, and building soil. We may discover through the death of plants that something is amiss. It is often the balance of organisms in the soil that is out of place.
Dr Elaine Ingham of the Soil Food Web Institute explains the importance of feeding the soil organisms the right food depending on the ecosystem you’re working with (see http://gbweekly.co.nz/2011/1/19/ecosystem-overview). She also describes the importance of different organisms in various ecosystems and the need to introduce them if they’re lacking. Inoculations of organisms into our garden ecosystem will help create balance and lessen the need to intervene with pesticides and fertilisers.
Concerning pastures (where bacteria are the dominant organism), the scientific review What Lies Beneath (www.country-wide.co.nz/article/12317.htm) suggests farmers should include rhizobia inoculant when sowing clover into previous scrub or tussock blocks. Lucerne, faba bean, lentil, field pea and vetch are also sold with a rhizobia inoculant to ensure good establishment.
Biodynamic farmers and gardeners use preparation 500 to inoculate the soil with microbes. Made from cow manure placed in a cow horn and buried in the ground over the winter, it is mixed with water and sprayed directly onto the ground in the autumn and/or spring. 500 stimulates biological life in the soil.
Compost made with lots of different greens, annual carbon (eg, straw), minerals, and manures in most cases will be the ultimate inoculum. You can add more inoculants to your compost to improve it: for example, yoghurt contains bacteria, mostly of the genus Lactobacillus (such as L acidophilus and L bulgaricus). Simply wash out your yoghurt container onto the compost pile.
Biodynamic gardeners use compost preparations to assist the composting process and improve its quality. Six different preps are used made from various herbs. These preparations are available from the Bio-Dynamic Association (http://www.biodynamic.org.nz/).
Compost tea is another homemade solution to improving microbial activity in your home garden. For lawns and vegetables, use compost made with soft carbon, eg hay (ie bacteria-dominated). For fruits and ornamental areas, use compost made with woody carbon (ie fungi-dominated). Try the easiest method to make it: the tea bag technique. Put two shovelfuls of compost into a sack, old pillow case, or old pair of pantyhose, tie the top shut, and place the bag in the bottom of a bucket. Add about one part compost to five parts water. Let it brew for seven to 10 days. Dilute the resulting “tea” with water until it is the colour of weak tea, and use either as a foliar on plants or directly on soil. Repeated applications constantly re-inoculate with beneficial microbes.
Compost teas are available commercially from several companies via the web:
http://www.environmental-fertilisers.co.nz/products/microbial-inoculants/microbial-inoculants.htm
http://www.biofeed.co.nz/
Worm tea is another simple additive provided your worm farm has a collection device. Can-O-Worm farms have a bottom chamber with a tap to discharge liquid into a watering can for dilution (roughly 1:10). Using bath tubs or other containers with a hole makes it easy to collect vermi-liquid.
Worm juice (as the schoolkids call it) is rich in microbes and nutrients.
Many of our fungal problems (and poor crop growth) in our vegetable or fruit gardens can be caused by the lack of beneficial fungi. In particular, mycorrhizal fungi are generally the missing link in our present growing environment. Two types of mycorrhizal fungi form symbiotic relationships with host plants: endo (or arbuscular) mycorrhizae, which associate with annual vegetables, flowers, grasses and row crops or broadacre crops; and ectomycorrhizal fungi, which link with most evergreen plants. Litter or soil from around healthy plants can be incorporated into the appropriate compost, which in turn will inoculate your plants when you distribute compost later on.
You can also purchase mycorrhizal fungi (and other microbial inoculants) already added to humic acids/compost from Environmental Fertilisers: http://www.environmental-fertilisers.co.nz/products/microbial-inoculants/microbial-inoculants.htm.
Trichoderma is a completely different type of soil fungus that lives near and on the root surface but does not form symbiosis. It acts as an antagonist to other soil fungi, including pathogens, and therefore helps to protect plants from soil-borne diseases. Trichoderma is used to treat silverleaf fungus in stonefruit and can be purchased as a powder or as a dowel through Wrightsons or FruitFed under the trade name Vinevax. Many fruit growers add trichoderma powder to the hole when planting new trees to ensure good root zone inoculation.
The benefits of bio-inoculants can be significant and include improved crop/plant nutrition, crop yields, and greater pest and disease resistance.
Sol Morgan
