Earthworm research spurs farmers to act

biodiversity earthworms farming biology science

A study of England’s farmland has found key earthworm types are rare or absent in two out of five fields and has led to the majority of farmers affected vowing to change the way they farm.

The results indicate widespread, historical over-cultivation, and may explain observed declines in other wildlife, such as the song thrush, that feed on these worms.

The #60minworms project was the first comprehensive worm survey concentrating solely on farmland and was carried out by farmers themselves – 57 percent of whom said they would now change their soil management practices as a result.

The scientist behind the survey, Dr. Jackie Stroud, a NERC Soil Security Fellow at Rothamsted Research, said: “Earthworms are sensitive and responsive to soil management which makes them an ideal soil health indicator. The aim of this research was to find a baseline of farmland earthworm populations that would be useful and used by farmers to assess soil health now and in the future.”

Biologists categorise earthworms by ecological role—with surface dwelling and deep burrowing worms the types most sensitive to farming practices, whilst the topsoil worms are generally unaffected by over-cultivation.

Earthworms perform a number of useful ‘ecosystem services’, and high numbers of earthworms have been linked to enhanced plant productivity.

This new citizen science project published today in the journal PLOS One, has revealed most fields have good earthworm biodiversity – meaning an abundance of all three types of earthworms were seen.

In Spring 2018, the average field had 9 earthworms in every spadeful of soil, with top fields having three times that number. One in 10 fields had high earthworm numbers of more than 16 worms per spadeful.

However, the study also revealed that 42 percent of fields had poor earthworm biodiversity – meaning either very few or none of the surface dwelling and deep burrowing worms were seen.

The absence of deep burrowing worms on 16 percent of fields is concerning, says Dr. Stroud, because they are ‘drainage worms’ with vertical burrows that aid water infiltration and ultimately helps combat waterlogging.

“The deep burrowing worms have slow reproduction rates so recovery in their populations could take a decade under changed management practices. In fact, we know very little about earthworm recovery rates.”

More than 1300 hectares were surveyed from all over England for the project, including fields managed under arable, potatoes, horticulture and pasture.

Earthworm research spurs farmers to act
Deep burrowing worm. Credit: Rothamsted Research

Each farmer volunteered to dig 10 regularly spaced pits across their field to make the observations, and an identification guide allowed them to allocate any sightings to one of the three main types of earthworm.

The success of this pilot project has already led to a much larger study, which recently concluded, says Dr. Stroud.

“Working with farmers led to the redesign of the pilot survey, culminating in a shorter, more efficient field assessment and a co-created earthworm identification guide, to help improve farmer confidence in earthworm monitoring.

“These improvements were well received, with farmers all over the country spending an hour of their time digging five soil pits and assessing their earthworm populations in the Autumn.”

Empowering farmers to survey their own soils would save about £14 million in soil health monitoring if rolled out nationally, she added.

Healthy Soils were not a headline indicator for the draft DEFRA 25-year plan for the environment, so the DEFRA policy aspiration of achieving sustainable soils is currently unclear.

Despite this, soil health is widely regarded as vital for both farming and the environment.

Dr. Stroud said: “Decisions made above the ground, whether by farmers or policy makers, influence the billions of earthworms that are engineering the soil ecosystem below the ground.

“Earthworms influence carbon cycling, water infiltration, pesticide movement, greenhouse gas emissions, plant productivity, the breeding success of birds and even the susceptibility of plants to insect attack.”

However, she added, as earthworms are sensitive to various farming practices, including tillage, rotations, cover cropping, organic matter additions, and pesticides, we need to do more to look after them.

“Crucially, working together with farmers, we now know typical earthworm numbers in agricultural soils and between us have developed a quick method for ongoing monitoring. Many farmers have reported they plan to survey again this Spring following benchmarking their fields last year.

“Soil health is complicated, but the path to doing things differently has to begin somewhere.”

This story is by by Rothamsted Research for https://phys.org

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

Which is better for plants, chipped mulch or shredded mulch?

Small Contemporary Urban Garden

Neither. Don’t use chipped mulch OR shredded mulch. Both of those will rob the precious nitrogen from the ground that your plants need.

Nitrogen is vital for healthy plants because it’s a major component of chlorophyll. Chlorophyll is the compound by which plants convert sunlight into sugars from water and carbon dioxide. Nitrogen is also a major component of amino acids which are the building blocks of proteins.

Plants are unable to use or take nitrogen directly from the atmosphere. They must uptake it through nitrogen forms that include ammonium and nitrate.

So, what should you use instead of chipped or shredded mulch? Composted mulch!

This is from my Quora answer: https://www.quora.com/Which-is-better-for-plants-chipped-mulch-or-shredded-mulch/answer/Matt-Harvey-84

Which is better for plants, chipped mulch or shredded mulch

Should I add diseased plants to my compost?

That’s a great question. According to gardenorganic.org.uk, some diseased plants can be added to your compost, however, plant materials suffering from soil-borne diseases such as clubroot and white rot should not be added to a compost heap.

Anything else can be safely composted in a hot heap. Diseases that don’t need living matter to survive, such as grey mould, mildews, and wilts, may survive in a cold heap.

But heat is not the only factor that will kill diseases: the intense microbial activity in a compost heap also helps to dispose of them. Some diseases, such as tomato and potato blight need living plant tissue to survive and will not last long without it. It is fine to add foliage suffering from these diseases to your hot or cold compost heap. If in doubt, leave it out. Problem materials can be sent to your local council green waste recycling facility where the composting methods are hot enough to kill any problem organisms.

that don’t need living plants to survive – grey mould, mildews, wilts – may survive in a slow, cool heap. But heat is not the only factor that will kill diseases – the intense microbial activity will also help to dispose of them.

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Can diseased plants be put in compost

Image courtesy of gardenseason.com