Question
QUESTION: The soil of my land is of old volcanic origin, in some places rather reddish brown, in others just brown, is poor, acid and well draining, sometimes it can get quiet dry, but with plenty of organic matter, mulch on top. I also applied the from the agricultural laboratory, based on a soil analysis recommended quantity of calcified seaweed to adjust the pH to a neutral level and added the required amount of potassium and phosphorus. However I rarely see any worms, which are supposed to live from organic material and to be essential in the fertility and health of the soil. They do not mix the mineral soil with the organic parts and do not transform much of the latter into for the plants absorbable matter, like I have seen it in other soils. Could it be that I do not have the right species of worms or is there another soil amendment required.
Alternatively I would also appreciate it very much, if you could send me a contact, where I can get the needed information.

ANSWER: Good question, my friend. I need a little more information to add to your facts-packed inquiry.

Where are you writing from? (zipcode or nearby city)?

Are you growing a Lawn on this property or anything else so far?

rsvp

---------- FOLLOW-UP ----------

QUESTION: - The land is located in the north of the Atlantic island of Madeira (Portugal) on around 1500 ft. altitude.
- I am growing mostly fruit and nut trees (also hedges and windbreaks), based on agroforestry and permaculture principles. For the addition of nitrogen I am mulching the fruit trees with acacia (probably A. maernsii) prunings since more than 5 years, and there are far more acacias growing than fruit trees, but the result is about as mixed as it can be. I also wonder, whether the eucalyptus, which grow here for about 50 years, might have had a negative effect on the worms.

Answer
I have a followup message for you from a fellow reader, my friend:

Questioner: Pat Tyler
Country: United Kingdom
Category: Organic Gardens
 
Subject: contact Madeira permaculturalist

Question: I would really appreciate it if you could pass my e-mail address onto the person in Madeira who was asking how to improve their soil.  I am hoping to move there soon, (to the Calheta region) and also want to create a small, edible forest garden. Would appreciate contact with like-minded individuals.

Many thanks,

Pat

--------------------

Now back to your question.

As I understand it, your volcanic Madeira soil was a rich, high-Clay, low-pH soil when the region was originally discovered in the 15th century.  Soil would test high in Magnesium and Iron, low in Potassium, acceptable for Phosphorus.

According to several sources, certain areas, perhaps yours, were ruined by faulty agricultural practices and then abandoned.  Some were rescued and cultivated, and much of the island is now considered a horticultural paradise.  

All of Madeira's animals were introduced at some point.  The islands were unpopulated when they were first discovered.  It is likely even the Earthworm population was introduced from Europe.  Many of the plants were introduced as well, including your Eucalyptus and Acacia, along with the Bananas, Avocados and Fruit Trees that fluorish there.

The dark red Clay you describe is probably Basalt.  Gray Trachyte and Trachydolerite Rocks, Yellow and Red solidified volcanic Rocks called Tufa, and a dark, porous lava Rock called Scoria are found in upper regions, mixed with Basalt-Tufa rubble.  Some of the Clay is so solid it holds water and cracks when dry.

Earthworms are widely viewed as indicators of soil quality and stability.  But they need a thriving microbial population and organic matter to become established in large numbers, among other factors.  

You expressed concern about Eucalyptus possibly damaging the Earthworm populations.  The leaves of the Eucalyptus are covered with oil glands and give it its distinctive aroma.  The oil itself is a strong natural disinfectants, and it is poisonous in quantity.  In Australia, Koalas and some other native animals eat Eucalyptus leaves. Eucalyptus oil is known to be an insect repellent, and it is used as an ingredient in mosquito repellents.  I have looked into this from every angle, and I can tell you that some people mulch their organic gardens with Eucalyuptus leaves with no damage to the Earthworm population.

Eucalyptus is native to the South Pacific.  When it was introduced by colonists around the world to different regions, it eventually developed into a problem species.  Nothing uses water like a Eucalyptus, and its high water consumption totally eliminated water tables.  In those areas, the previously rich soil turned into a desert overnight, killing established Flora and throwing off the balance of Nature.

Acacias by the way are famous for the headaches they give gardeners, caused by the relentless production of germinating seeds, and cured by the unforgettable fragrance of their blooms.  They are legumes and probably very good for Nitrogen.  Can you supplement the work they are doing -- with a short cover crop, perhaps?

My guess is that the soil you have simply will not support the Earthworm population you want to see.  I also think you are on the right track, given that you have arranged for soil testing and probably taking other measures you did not mention.  I would even guess they are considerable measures.  It was my understanding that you also have access to certain forest/timber byproducts and manure.  Are these options you can use to supplement your Nitrogen?  How recently did you work on correcting the acidic soil you have?  That's something that takes time and patience.  It is also a significant factor in the reproduction rate of many Earthworms.

I can't see how the low pH would NOT impact the Earthworm population negatively.  But it is impossible to fix this overnight.  Have your soil tested again for pH 6 to 12 months after your Seaweed amendments are incorporated to make sure you are making progress.  FYI: I am happy to answer any questions you would like to send me.  I'm ready to jump on the next plane after all this extra information people are giving me about how beautiful Madeira is (not to mention the exquisite wine).  Unfortunately, for a New Yorker, work is never done.