About humus, compost and manure in the organic kitchen garden in Almeria, Andalucia
Now is the time to look at feeding the ground and preparing it for the spring sowings and plantings. At the end of November there is not much ready, I am still pulling leeks and cutting broccoli and I sowed a double row of broad beans that should be ready in spring. I have most of the organic kitchen garden ready to be composted and manured.
This is the first winter in the organic kitchen garden. It has never seen any compost or manure, so I am starting from square one. The soil here is what I call barranco soil, it is sandy, alluvial soil that has been laid down over hundreds of thousands of years. In summer, if it is allowed to dry out, it becomes very hard, almost like clay soil. When it is wet, unlike clay, it is workable. It tends to be alkaline although as far as I can tell it is full of the nutrients that plants need, they have just been washed down into the free draining ground. Because there is no organic material in the soil, plants find it hard to root and even harder to extract the nutrients they need. Since last March, I have been sowing and planting where I could. I found that the brassicas; sprouts, broccoli, cabbage, really liked the soil as it was, hard and alkaline, but just about everything else suffered and did not produce the good crops I am used to in Andalucia.
So, let me tell you something about humus. Humus starts life as compost that has been produced from organic waste; prunings, peelings, fruit skins, leaves, coffee grounds, animal and/or poultry manure, shredded woody material, tea bags, biodegradable cardboard, annual weeds, grass cuttings, crushed egg shells and so on. The compost is put onto or dug into the ground. Humus is produced in the soil. All that lovely compost you have produced continues to break down. A lot of microscopic action will still be taking place as the bugs, bacteria, fungi, and microbes feast on the compost. It can take many years for the compost to be reduced to humus. As the little critters continue their dinner party, they break things down on a molecular level, slowly releasing nutrients into the soil for plant uptake. Humus is what’s leftover at the conclusion of the feast, which is when all the usable chemicals in the organic matter have been extracted by the microorganisms.
Over time, the soil becomes darker and more friable, making it easier for plants to develop good roots. The soil also becomes better at retaining water, think of a sponge, so plants need less watering, a bonus here in Andalucia. Finally, the darker soil absorbs heat from the sun so you can plant or sow a little earlier than you would normally.
Humus will remain in the soil for hundreds of years.
Tomato Hornworm Moth
My compost bins are simple, four wooden pallets screwed together, lined with cardboard and with a plastic matting over the top. I have two alongside each other so that one can be filled then turned into the second one. That way I always have one being topped up. By the time the first is full, the second is full of decomposed compost, ready to use.
Compost is made by layering the woody material, green material and manure in a container and allowing the pile to rot down. A little water is needed to help the process along. After a month in summer and two in winter, the whole pile is turned so that the top stuff goes to the bottom and the drier, outside bits go to the centre. How long the rotting process takes depends on the weather, in the heat of summer it can be as little as three months, in winter double that. I have found that the best compost is made if woody stuff is shredded first. My shredder is only an inexpensive electric machine that I have been using for over 12 years. I must remember to take its blade out and have it sharpened; I have been thinking that for at least three years. I also use a riddle when I am emptying the compost ready bin so that the lumpy, woody, non-composted bits are left in the riddle. They go through the shredder when they are dry and get thrown in the bin currently being filled.
You can never have too much compost.
The Good the Bad and the Ugly
I recently found a fantastic source of horse manure, as much as I want, and it is the good stuff with very little straw in it. Normally manure should not be put directly on the ground, it should be composted or at least allowed to weather for a couple of months. However, I know that the ground I am working now will lie fallow until March and, as I have remarked, it has never before seen any compost or manure. This is an opportunity to give it a really good start. The first layer of horse manure, probably 10 centimetres thick, was roughly forked into the soil to a full fork depth. A second layer, equally thick, went on top of the dug soil and that should rot into the top layer of soil over the winter.
In the spring I will lightly fork and rake the ground and make my sowings and plantings. That should do it for the root crops and legumes, in fact it may be a little much for them, we shall see. Tomatoes, courgettes, aubergines, peppers, chillis, cucumbers and squash are all gross feeders so they will receive a top dressing of home-made compost. That is the plan.
At the end of September, I reported the presence of a tomato hornworm caterpillar in the garden. Thanks to Heather from Urcal, who put in lots of research, I can tell you that I was wrong. It was a Hummingbird Moth Caterpillar, Hemaris Diffinis. So, my tomatoes are safe next year, and I can look forward to seeing a Hummingbird Moth flitting between the flowers. They are delightful creatures, almost as large as their feathered namesakes.
Because the potato is growing in a confined space (see September and October’s articles), it needs feeding, so I have given it a good top dressing of home-made compost. I will do the same again about the middle of December. It looks as though we are still on track for new potatoes at Christmas.
The sprout plants planted out in July now have small sprouts in the leaf axils. They are about the size of large peas. To encourage them to swell I have removed the tops off half the plants, sprout tops can be cooked like cabbage and are a wonderful flavour. It will be interesting to see how the topped sprouts compare to the non-topped sprouts.
The next article will not appear until the Christmas festivities are over so, to all you gardeners out there, have a very merry, and fruitful, Christmas.