Maintain Ecobed Productivity.


Latest Update 24th July 2018.


Most organic gardeners seem to spend a lot of time refining their soil conditions using (organically approved) amendments.  I have formed the view, influenced by Dr Elaine Ingham of Soil Foodweb fame, that most soils in the world contain all the minerals plants will ever need.  These minerals are locked up in the soil's rock particles and don't appear in soil tests which measure only soluble mineral content.

I also believe that a soil full of beneficial microorganisms and their predators are capable of extracting these minerals as and when the plants need them in return for photosynthesised sugars and other energy foods produced by plants.  Check out my blogpage explaining the Soil Foodweb for more details.

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This article is linked to my Growing Organic Vegetables blog, and provides support for those readers who wish to grow vegetables in Ecobeds.  It is set in a warm temperate climate, and will need to be adapted for other climatic conditions.

Soil Preparation and Maintenance.
To maintain a well structured healthy soil, beneficial soil microorganisms need to be fed regularly.  Although plants provide this food in their root zone, control of soil structure, soil pests and soil fertility outside the plants' root zones depend on a high organic material content in the soil.  So I take the following measures to ensure this is always the case .
  • Every time vegetables are harvested in my Ecobeds the plant debris and old mulch is removed from the soil's surface.  This valuable organic waste is stored (dry) for use in the next compost making process.
  • A 60mm layer of fresh homemade compost is then applied as a dressing on top of the soil, and to ensure it stays moist, is covered with a 50mm layer of fresh straw mulch.
  • Soil microbes feeding on this compost flourish in these conditions and are ready when required to set up mutually beneficial relationships with the next crop.
  • To help maintain high fertility and a healthy soil food web in my Ecobeds, I apply a drench of compost extract in January, February, march, April, May, July and August.
Worms are invaluable builders of soil structure and help provide important plant nutrients by feeding on bacteria in the plants' root zones.  Their castes are plant nutrient dense, and they need to be encourage to live and multiply in Ecobed soils.  

Because Ecobed soils are isolated from the surrounding ground, positive intervention is needed to maintain a healthy worm population.  My worms are well fed with continuous applications of microbe rich compost and exudates from plants' roots.  To help maintain worm diversity and vigour, healthy worms found elsewhere in my garden are added to the soil from time to time.
This works best when I use these mini worm farms as a worm entry point to each bed.

They provide a protected environment, rich in raw organic waste from the kitchen, to help the worms recover and breed and eventually migrate into other parts of the bed.  The casts they leave behind when the farms are relocated (periodically) are excellent sources of plant nutrition.
Plant Foliage
  • My Ecobed plants are sprayed with aerated compost tea in June, September, October, November and December to protect them from foliar pests which are particularly active in spring.
  • Plant foliage is strengthened by a coating of the beneficial microbes grown in aerated compost tea.  They bond themselves to the plant's leaves and form a glossy barrier to pests and diseases.
  • As a bonus, these microbes also fix nitrogen which is used by the plants in return for energy food exudates delivered by the plants through their leaves.
Managing Sunshine
  • Growing clusters of crops too close together limits their access to sunlight for photosynthesis and reduces their potential size and vigour.  It's important to keep in mind the full grown size of the plants before allocating space in which to grow them.
  • You can of course plant some crops more densely than usual.  These crops can be thinned as they grow and the thinnings are used for food (baby carrots are delicious).  The remaining plants find themselves free to grow to full size expanding into the freed up space left by the thinnings.
  • You can also use fast growing "catch crops" in tight spaces between larger slow growing crops.  By the time the main crop begins to shade the catch crop, it is ready to be harvested, and the main crop then fills the vacated space.
  • Some plants like cabbage and lettuce, are best grown in winter because fierce summer sun wilts them and causes them to "bolt" to seed.  However, when I grow them in summer I use exclusion netting with a 20% shade factor to take the edge off the sun and protect them against Cabbage White Butterfly larva.  When temperatures exceed 35C, I add a temporary layer of 75% shadecloth.
  • In the same way as gardeners set out their herbaceous borders with tall plants at the back and small ones at the front, so should vegetables be arranged in an Ecobed.
Managing Water resources.
  • Water consumption by plants depends on their size and rate of growth, but in conventional gardens a lot of extra water is lost due to evaporation and drainage to the subsoil.  Ecobeds are designed to dramatically reduce this loss.  
  • There is no water loss to the subsoil in an Ecobed, but persistent flooding rain drains readily through the overflow pipe when the bed's capacity to absorb water in its soil and store water in its tank has been exceeded.
  • The combined effect of a very absorbent soil and a generous layer of mulch virtually eliminates evaporation even in very hot weather.
  • I use rainwater in my Ecobeds almost exclusively, because treated tap water tends to accumulate unwanted chemical residues in the soil which kill beneficial microbes and other beneficial creatures.
  • My combined rainwater storage capacity (including Ecobed water tanks) is about 7500 litres, and even in very dry summers this is usually enough to get me through.
  • To get the best out of my water storage capacity, I fill Ecobed water tanks when rain is expected.  This leaves space in my rainwater tanks to capture more rain off my roof.
  • I used 2000 litres of filtered mains water to get me out of trouble in 2016/2017.  Its a damage limitation strategy to be used only in an emergency.  The worst of the nasty chemicals are removed using a domestic water filtration system, but it is not ideal, and I would have to consider shutting down the beds for a while in serious drought conditions.
  • I haven't had to do this yet, but in the event of a drought, I would strip the Ecobeds of plants before they ran out of water completely, and I would cover them with extra mulch and a layer of shade cloth to minimise evaporation.  This measure would hopefully preserve the living organisms in the bed until it rained, or until untreated water could be obtained.