British scientists have cracked the global earthworm mystery: they have worked out how the planet’s great subterranean reprocessing system copes with the poisons that would choke most herbivores.
Earthworms underwrite almost all life on earth: they drag fallen leaves below the soil and digest them, to excrete that rich mix of loam and living things called topsoil. Every year, 35 billion tons of dead grass and leaf litter get turned over by the worms and other soil fauna. But the catch is that some plants are really poisonous, and all plants contain some toxins designed by evolution to discourage demolition by herbivores, and these toxins carry on working even after leaf fall.
But earthworms seem to have the stomach for almost anything vegetable. And Manuel Liebeke and Jakob Bundy of Imperial College in London have the answer. They and colleagues report in the journal Nature Communications that that the earthworm’s gut contains a suit of molecules that neutralise the polyphenols that give plants their colour, serve as antioxidants and discourage many ravenous grazers.
The worm’s internal defences have been identified and pinpointed by sophisticated visual imaging, and named drilodefensins. The researchers calculate that drilodefensins are so abundant that for every person on the planet there may be at least one kilogram of the molecules in the worms under their feet.
Which is why we are all here: researchers last year confirmed that the simple existence of earthworms in the soil means that crop yields may increase on average by 25% and the weight of all foliage above ground by 23%. The great biologist and evolutionary pioneer Charles Darwin called them “nature’s ploughs.”
But, the Imperial team point out, without the earthworm’s arsenal of drilodefensins, there wouldn’t be much soil to plough.
Continue reading “Answer To Earthworm’s Ability To Digest Poisons Unearthed By Scientists”
Take a look at this amazing resource I’ve just discovered, it’s Dr Elaine Inghams lessons on the soil food web, as well as creating your own composts and compost teas/extracts. The information contained hereinafter is often behind a paywall.
“Elaine Ingham, Chief Scientist at Rhodale Institute came to Hawi, Hawai’i in July 2012 to deliver a 5 day seminar dedicated to studying, understanding, and improving our soil biology to assist in ecologically sound agricultural practices. This is where I got my introduction to the microscope and learned much of it’s importance. This was some of the best 30 hours of class ever, and I often re-watch this epic series to refresh myself and discover more as I tune my own magnification of understanding this microscopic wonderland.” – Drake of Natural Farming Hawaii.
This presentation consists of 18 videos containing a total of 26 hours of footage. For information purposes the audio quality is a little poor and the presentation slides are slightly out of focus.
“Neem seed cake also reduce alkalinity in soil, as it produces organic acids on decomposition. Being totally natural, it is compatible with soil microbes, improves and rhizosphere microflora and hence ensures fertility of the soil. Neem Cake improves the organic matter content of the soil, helping improve soil texture, water holding capacity, and soil aeration for better root development.” – Wikipedia
There it is, another added benefit of the Neem Cake is its ability to create a favourable growing environment on the more alkaline soils. So not only are you getting an excellent source of organic nutrients and the “pest and disease resistance” it’s also working as a soil conditioner too.
The below shows how soil PH affects the availability of nutrients to the plants, it’s useful as a general guide.
A biochar-based soil improver, enriched with species of mycorrhizal fungi, actinomyces bacteria and trace elements is helping to combat the root-knot nematode – significantly increasing yields for organic tomato growers in Portugal.
Biochar is a highly porous, high carbon form of charcoal used to improve soil nutrition, growing conditions and soil structure. It is made from any waste woody biomass that has been charred at a low temperature with a restricted supply of oxygen, a process called pyrolysis. This process results in a stable form of carbon that is removed from the atmospheric carbon cycle when added as a soil amendment.
“Where we have incorporated Carbon Gold Soil Improver in the very sandy soil at our Portuguese nursery we have seen a 7% yield increase and a lower level of nematode infestation than areas that were not treated.” – Paul Howlett, Head of Agronomy at Vitacress Tomatoes
Vitacress Tomatoes (formerly Wight Salads) trialled Soil Association and SKAL approved enriched biochar from UK biochar company, Carbon Gold, from June 2013 to April 2014 in order to improve the sandy soils at their Portuguese nursery. They applied 2kg per square meter to a 5 hectare trial plot taken to a depth of 30cm, analysing the outcomes against a 5 hectare control area with the same crop.
The increase in crop yield was significant. By week 24 they realised a 7% higher yield, (an additional 0.9kg per m2) compared to the 5ha control plot. This equated to an additional 2,600kg Piccolo Cherry on the Vine tomatoes.
In the Vitacress trial plots it became evident that the colonies of mycorrhizal fungi, using biochar as a refuge in the soil, were able strike out at parasitic Meloidogyne nematodes, enticing and devouring the microscopic pests and protecting the plant roots from attack.
Continue reading “Biochar Helps Combat Nematodes And Increases Yields”
Found this book on soil biology which highlights the importance of this soil food web. Excellent microscopy photos here, well worth checking over if you’ve never seen them before or if your thinking about looking at soil under a microscope. It also covers several other things like Seasonal Microbial Activity, Typical Numbers of Soil Organisms in Healthy Ecosystems, Methods for Measuring the Food Web etc. I loved reading this, I’m sure anyone who’s interesting in anything plant/soil related would too.
DIRECT DOWNLOAD: https://planetpermaculture.files.wordpress.com/2015/04/soil-biology.pdf
A good little video showing different aspects that affect how well a soil manages the water that falls on it, will it run off or move down into the soil. Will it have a negative impact with run off and flooding or will it have a positive impact on plants and aquifers.
Altough only an introduction it touches on things such as soil compaction, drainage, leaching, capillary action in unsaturated soils, gravity as the dominant force that moves water downward in saturated soils. The soils texture and structure, platy, prismatic, columnar, granular, and blocky soils. Percolation rates and pore sizes etc
A thorough, free, easy-to-read guide for ecological soil management which includes nutrient management, nutrient cycles, cover crops and other soil-improving practices. “Building Soils for Better Crops is a one-of-a-kind, practical guide to ecological soil management, now expanded and in full color. It provides step-by-step information on soil-improving practices as well as in-depth background—from what soil is to the importance of organic matter. Case studies of farmers from across the country provide inspiring examples of how soil—and whole farms—have been renewed through these techniques. A must-read for farmers, educators and students alike.” LINK: http://www.sare.org/Learning-Center/Books/Building-Soils-for-Better-Crops-3rd-Edition DIRECT DOWNLOAD: https://planetpermaculture.files.wordpress.com/2015/04/buildingsoilsforbettercrops.pdf
I found this a really interesting video showing how bacteria and fungi, along with the rest of those little critters from the soil food web work together to create humus (soil/compost) from just a sand substrate. This captures the process over a one year period in a time-lapse video showing the formation of algae and moss on top of the inoculant and then seeding it to create plants, as the process develops it results in the creation of a soil layer. It also details the process she went through to get to this point and at the end shows us some microscopy sequences of the organisms in this soil food web. There is also another video below which briefly shows a little more details. Seeing this makes me want a microscope even more now.
MORE INFORMATION: https://vimeo.com/117682077
EBOOK (GERMAN): http://www.boku.ac.at/seiten-ohne-oe-zuordnung/humusplattform/humusbuch/
DIRECT VIDEO DOWNLOAD: https://vimeo.com/122856716/download?t=1427851098&v=348742480&s=e938bd1055c8c0714e5b837fefae97e2
Laboratory tests were conducted to compare the effects of various concentrations of glyphosate and 2,4-D on earthworms (Eisenia foetida) cultured in Argissol during 56 days of incubation. The effects on earthworm growth, survival, and reproduction rates were verified for different exposure times. Earthworms kept in glyphosate-treated soil were classified as alive in all evaluations, but showed gradual and significant reduction in mean weight (50%) at all test concentrations. For 2,4-D, 100% mortality was observed in soil treated with 500 and 1,000 mg/kg. At 14 days, 30%-40% mortality levels were observed in all other concentrations. No cocoons or juveniles were found in soil treated with either herbicide. Glyphosate and 2,4-D demonstrated severe effects on the development and reproduction of Eisenia foetida in laboratory tests in the range of test concentrations.
Herbicides containing glyphosate are widely used in agriculture and private gardens, however, surprisingly little is known on potential side effects on non-target soil organisms. In a greenhouse experiment with white clover we investigated, to what extent a globally-used glyphosate herbicide affects interactions between essential soil organisms such as earthworms and arbuscular mycorrhizal fungi (AMF). We found that herbicides significantly decreased root mycorrhization, soil AMF spore biomass, vesicles and propagules. Herbicide application and earthworms increased soil hyphal biomass and tended to reduce soil water infiltration after a simulated heavy rainfall. Herbicide application in interaction with AMF led to slightly heavier but less active earthworms. Leaching of glyphosate after a simulated rainfall was substantial and altered by earthworms and AMF. These sizeable changes provide impetus for more general attention to side-effects of glyphosate-based herbicides on key soil organisms and their associated ecosystem services.
DIRECT DOWNLOAD: https://planetpermaculture.files.wordpress.com/2015/03/srep05634.pdf