Worms and their place in our soils’ delicate ecosystem

Worms and their place in our soils delicate ecosystem

It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organised creatures.

– Charles Darwin, The Formation of Vegetable Mould through the Action of Worms (1881)

Here’s a very interesting article by Sarah Johnson, PhD Researcher in Environmental Science, King’s College London.

Not all wildlife is created equal in our eyes. Take the earthworm, which doesn’t have the widespread appeal of larger, more charismatic animals such as gorillas, tigers or pandas. Worms are never going to get a strong “cute response”, and they won’t ever be the face of a conservation campaign.

But what Darwin rightly recognised is that – panda fans avert your eyes – worm conservation is much more important once we factor in their provision of what we now call “ecosystem services”, which are crucial to human survival. Darwin spent 39 years studying these animals for a good reason. In fact, earthworms have even been ranked the number one most influential species in the history of the planet – above dinosaurs and humans.

Why care about the worm?

Ecologists consider earthworms “keystone species” because of how much they influence the physical, chemical and biological properties of the soil. Here are just some of the reasons why:

Earthworms are recyclers. They play a crucial role in breaking down organic matter and fertilising the soil, simply through their constant eating and pooping (about 1.5 times their body weight a day). What comes out the other end – known as a worm cast – is full of nutrients and bacteria that are beneficial for plants. Scientists have measured up to five times the amount of key nutrients in worm casts compared to surrounding soil.

Worm cast has up to five times more nutrients than the surrounding soil. photographyfirm / shutterstock

A study in Hawaii found that replacing a portion of standard fertiliser with vermicompost (compost from worm casts) increased yields of crops such as tomatoes and strawberries by 30%. It’s hard to generate industrial amounts of worm cast, of course, and vermicompost remains more expensive than commercial fertiliser. But it’s an intriguing example of how earthworms can help humans.

Earthworms are great “soil engineers”. As they move through the soil, earthworms loosen and mix it up, helping to aerate and drain it. This brings nutrients to the surface, making the soil more fertile, and helps prevent flooding and erosion.

Earthworms are barometers of soil health and toxicity. They’re very sensitive to soil pollutants such as pesticide residues or unwanted heavy metals (zinc, lead and so on), and they are badly affected by changes in land use such as deforestation to clear the way for intensive farming. This means the health of local worms is proving to be a useful tool to assess the impact of different land usage and pollutants.

Juicy earthworms are an important food source. They are protein-rich and feed a number of animals, such as the European badger.

Many food chains eventually lead back to an earthworm. nate samui / shutterstock

Earthworms can help repair damaged soil and may provide solutions to man-made problems. Research suggests that earthworms could help to clean up land contaminated with toxic heavy metals such as lead.

Other studies show how earthworms can speed up the restoration of degraded land in the tropics, while research in northern Vietnam found that reduced earthworm diversity due to land use change also had a significant knock on effect on soil fertility, water drainage and soil erosion.

So, earthworms are our underground allies – if we treat them right. Earthworms make it possible for us to live on the planet, simply by eating and pooping, and ploughing up, ventilating and fertilising the soil along the way.

‘I disagree with this article.’ Harvey BarrisonCC BY-SA

Climate change and human intervention are fast-tracking the world’s loss of biodiversity. The plight of the tiger in India and the orangutan in Indonesia are well known, but scientists are also becoming concerned about earthworms and other animals that we are less familiar with, but which we can’t afford to lose.

If pandas go extinct, it will be very sad. But, a world without earthworms? Arguably without earthworms in our soils, life could vanish pretty quickly. We would have less food, more pollution, and more flooding.

No matter how cute a panda looks, it is Darwin’s “lowly” earthworms that are doing dirty, but crucial, work in the soil below.

This article was written by Sarah Johnson,PhD Researcher in Environmental Science, King’s College London for http://theconversation.com

Do I need to clean my pruning shears? How Do I prevent rust and bacteria from developing on my secateurs?

how to clean gardening shears

Do I need to clean my pruning shears? How do I prevent rust and bacteria from developing on my secateurs?

From cutting away branches and pruning shrubs to gently snipping a beautiful flower to display in a vase, your shears can be one of the most important tools in your garden.

The one thing you don’t want is to spread harmful diseases, eggs and bacteria from plant to plant.

The blades of your shears can easily start to rust, become dirty, become sticky with sap and develop bacteria that can infect your healthy plants, however this can be prevented with these simple and helpful tips.

Use a stiff brush with a bucket of warm soapy water. Washing-up liquid works best, it is easy to rinse off and doesn’t leave a harsh chemical residue on the blades.

Use steel wool If the blades have started to rust. Sandpaper can be used as well.

After washing and rinsing, soak your shears for a few minutes in a pail of water mixed with a spoonful of bleach to destroy bacteria, eggs and other harmful organisms on your blades.

After soaking, dry them well with a cloth or air dry them.

Once they are dried, spray lubricating oil on them to prevent them from rusting.

Make sure to keep your shears hung and out of the elements when not in use.

Follow these simple steps and you will find this valuable garden tool will provide you with many, many years of quality service.

What are adelgids and how do I get rid of adelgids?

Conifers are a tree that bears cones and evergreen needlelike or scalelike leaves.  If you have conifer trees you may have to worry about Adelgids, which are are aphid-like insects that suck the sap from conifers.

Adelgid infestation close up zoomed in
woolly adelgid infestation Photographed by Michael Montgomery

Adelgids can cause distortion of shoots, affecting the appearance of trees. Yellow, winged adults leave galls in late summer and lay eggs on host plants. The nymphs soon hatch and overwinter close to buds. In spring these nymphs feed on plant sap but do not cause galls, maturing into light green wingless females. These females lay eggs covered in white waxy threads. The nymphs hatching from these eggs induce the galls when they feed at the base of needles. The galls contain numerous chambers within which groups of pale orange nymphs develop.

Adelgids only lay eggs, and never give birth to live nymphs as aphids do. Adelgids are covered with dense woolly wax. A complete adelgid life cycle lasts two years.

Adelgid nymphs are known as sistentes, and the overwintering sistentes are called neosistens.

Rain can kill adelgids by dislodging eggs and sistentes from trees.

So now that you know a bit more about adelgids, let’s discuss the reason why you’re probably reading this:

How do I get rid of adelgids?

The damage adelgids cause is often minor and can usually be tolerated, however, if you wish to remove adelgids from your plants, here are a few suggestions.

Adelgids can be difficult to kill with insecticides as they’re protected by waxy secretions. In addition it’s only feasible to treat adelgids on trees that are small enough to be sprayed thoroughly. It’s quite difficult to deal with  infestations on very tall trees.

hemlock wooly adelgid-bug macro microscope

The following insecticide information is from the RHS

  • Organic sprays, such as natural pyrethrum (e.g. Bug Clear Gun for Fruit & Veg, Defenders Bug Killer, Ecofective Bug Killer (also contains fatty acids)), fatty acids (e.g. Solabiol Bug Free, Doff Greenfly & Blackfly Killer) or plant oils (e.g. Vitax Organic Pest & Disease Control, Origins Bug Control) can give some control of adelgids. These pesticides have a very short persistence and so may require reapplication to keep adelgid numbers in check
  • More persistent insecticides include the synthetic pyrethroids lambda-cyhalothrin (e.g. Westland Resolva Pest Killer), deltamethrin (e.g. Ultimate Fruit & Vegetable Pest Killer) and cypermethrin (e.g. Py Bug Killer)
  • The systemic neonicotinoid insecticide acetamiprid (e.g. Bug Clear Ultra) can also be used

The College of Agriculture, Food and Environment offers some clever ideas for controlling and eliminating adelgids including:

Spraying foliage with insecticidal soap or horticultural oil at the proper times during the HWA life cycle.

Using a systemic insecticide that moves with the tree sap and is consumed by the adelgids as they feed. 

There are three main methods for introducing insecticides including trunk injection. soil injection and soil drenching.

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