Soil Fertility. Learning from the Past.

I have been reading books on Traditional Indian Agricultural practises, in order to improve the way that I maintain my soil fertility. Combining this knowledge, with what I already know, and what I’ve read about Chinese methods, should see another boost in fertility, and hopefully plant health. What I am learning, and the way that I am applying that knowledge is still developing, but there are some things that I can share now.

Adding fresh soil

In China the farmers used to drag the mud out of canals and drainage ditches to add to their fields, moving tonnes by hand. In India they did the same thing with the mud from inside their water storage tanks (reservoirs). The soil had been washed downstream (eroded), or washed into the tanks by the monsoon, and would contain minerals and organic matter.

My own reading has told me that a more stable humus is formed when organic matter decomposes in the presence of clay particles, so how can this knowledge be combined?

First of all I add my own soil, which is a very heavy clay, to my compost heaps, and to the deep litter systems of my ducks and chickens. The soil comes mainly from molehills collected from my lawn and the grass verges next to my property. I get up to a bucket a day like this. I also regularly empty my duckpond, scrape the sludge out, and now layer it in my compost heaps.  The compost formed is the best that I have ever made, and there pictures in an earlier post MAINTAINING SOIL FERTILITY.

The buiding of this heap is described and recorded in an earlier post PLAYING WITH COMPOST.

I have also started to double dig some of my vegetable beds. I remove the first spit of topsoil, and instead of adding it back to the last trench, I am removing it, storing it until next year, when it will form the base for my own potting mixtures. The surplus is going onto the compost heap, with some added to the chicken deep litter beds. The reason that I am double digging is shown in the picture below.

Soil profile picture

Soil profile picture

The picture shows a lump of soil dug today. The dark colouring in the top couple of inches is organic matter. This bed is about eight years old, was never dug, has had lots of compost layered on the surface, and has recently grown Rye, with a white clover and chicory intercrop. The organic matter has not been pulled down into the soil by worms, which is what the ‘no-dig’ proponents say will happen. The only organic matter below the top couple of inches are the chicory roots, which have gone down more than 12 inches. The double digging allows me to add organic matter right through the soil profile down to a depth of of about 18 inches, and should allow the next crop (Winter Wheat) to get its roots down into the gaps created by the digging.

Returning all crop wastes

In India, most of the crop wastes were removed and used to feed animals, the manure from which would be returned to the soil. It might seem inefficient to us, but the animals were used to plough, and for transport, and it would seem that the farmers would choose varieties of crops whose stalks were better as fodder, rather than purely for the human food value. One benefit of this system is that the animals stomach acted as an instant compost heap, crushing, grinding, and fermenting the organic matter, and adding beneficial microbes. It’s much less work to gather up cow pats, than to make compost, and it doesn’t leave large rat hotels.

In China organic matter was fermented/retted, before being mixed with soil, dried, ground, and then taken to the fields. The animal stomach does seem a bit easier.

At the moment we have no ruminants to process waste material, so I soak weeds, nettles, etc. in water until they have broken down, use the water as a plant food, and add the organic matter directly to the vegetable beds, or to a compost heap. I would consider keeping goats, but am not sure that I want the added restrictions that keeping them would bring. I am given a steady supply of fresh horse manure. I would like to use it in the chicken deep litter bed, but my supplier also keeps chickens and ducks, so I am wary of introducing potential disease to my flocks. Instead I soak it for a few months before composting, or for use as a plant feed. The latest batches have been used to start two more bathtub wormeries.

bathtub wormeries

bathtub wormeries

Not only does it make excellent worm feed, but the warmth given off as it slowly decomposes also helps to prevent the worms from freezing during the Winter. With a steady supply, the temperature can remain warm enough for the worms to continue to breed right through the Winter in outdoor beds, and they find the ideal temperature for themselves by moving closer/further away from the heat.

Original Bathtub Wormery

Original Bathtub Wormery

Collecting leaves and woody material.

Prior to the enclosure of the forests by the British, Indian farmers would collect woody material from the forests/commons. This added organic material or minerals to the soil in a number of ways.

  • Branch material was added directly to the soil before planting. Sometimes as it was, at others it was burnt, and the ash left to feed the crop. The burning was done by creating a layer of woody material over the growing space, and covering with a layer of soil to keep the temperature low. The heat would kill weeds and weed seeds, with the ash adding minerals to the soil.
  • The farmers also collected fodder for their animals, which was then turned into manure, to be added to the fields.
  • Finally, wood was used for cooking, and the ash was used to grow crops.

All of these methods allowed nutrients to be harvested from the wider environment, to replace those lost.

This has been the latest addition to my soil fertility programme. I already use my wood ash in the garden and compost heaps. Now I try to collect at least one wheelbarrow full of tree prunings, weeds, nettles, comfrey, or lawn clippings every day. These are then added to the poultry deep litter beds, saving the purchase of bedding material,

Chicken Deep Litter System

Chicken Deep Litter System

added to the compost heap, or composted separately in ‘Builders bags’

Composting prunings

Composting prunings

to add to the soil later. I will also add some directly to the soil after the leaves ave fallen, cut up into small pieces, as a soil amendment.

Not yet begun is my plan for old nettles, couch grass, thistles, and other weeds. I have too many weeds. By the time that I have enough time to deal with these, most are sat there with loaded seed heads waiting to drop. Rather than try to compost them, I intend to burn those nearest to my vegetable beds, using some of my surplus kindling wood to get a fire going in a metal incinerator. This will destroy the weed seeds, will give me a mineral rich ash to add to my soil, and help to remove fertility from the areas where the weeds are currently dominating. With more time available to maintain these spaces, I should be able to harvest more of this material before it goes to seed, saving work.

Humanure

In both China and India Humanure was a highly valued way of returning nutrients to the soil. Here I suspect that my wife would be a bit squeamish about crapping into a bucket. I am planning to use a WET system to process grey water, and outflow from my septic tank, harvesting the nutrients by cutting reeds and other plant material. I am trialling a new system for composting my dog poop, using shredded miscanthus, soil, my own urine, and wood ash, in a dustbin.

compost

Composting Dog Poop

So far it is looking like a bin will handle about 6 weeks worth of ‘outputs’. What I want to see is how rapidly this potent mix will take to convert into usable compost, and how effective it is. I can then potentially use a system like this for humanure, should the need/opportunity arise.

Why Bother to Build Soil Fertility?

If all of this seems like too much trouble, that’s probably because you, and I don’t rely on our gardens/smallholdings to produce all of our food, and our livelihoods, and to be in a good enough condition to support our descendants for generations. I love the idea of building soil fertility rather than depleting it, and of using traditional knowledge, combined with what we know now, to do so.

7 thoughts on “Soil Fertility. Learning from the Past.

  1. annisveggies

    Really interesting as always Deano. Your soil really does seem to be a challenge with its clay. I must just be very lucky with my garden which has never been dug and seems magically to turn light and fluffy just by adding mulch to the surface. My previous two gardens were very heavy clay and not far from here but I gardened very differently in those days.

    I completely agree with you about using every means possible to preserve, store and recycle nutrients importing and exporting as little as possible. I have never put out the council’s green waste bin as I cannot bear to export fertility or potential fertility out of the garden. If the compost bin is full and I cannot reasonably accommodate any more mulch on the garden (because other people may be offended by the aesthetics) I dump it into the green bin and that seems to act as a compost bin over winter and I can turn the contents out in the spring where I want them.

    I have however not been able to save and use the tree branches which we have had removed or the hedge that was recently replaced by a fence, though I wish I could have done. If I cut small branches I just put them down on the ground out of sight or on one of the paths at the back of the patch and eventually they decompose. They don’t get in the way and are not unsightly as the foliage soon covers them or I put more mulch on top!

    I have just been given a gift of the Buffalobird Woman’s Guide to Traditional Methods, which I asked for having read your recommendation. Like you I feel we have so much to learn and little enough time to do so. The reasons become more pressing every day.

    All the best, Anni

    Reply
    1. Deano Post author

      Hi Anni
      We have loads of material to use, but not everybody is so lucky. I want to find/identify/test ways that can help people to grow more, and the farmers of the past, or who use traditional methods, are potentially my best resource. I hope that you enjoy Buffalo Bird Woman’s Garden. I can also recommend ‘Tending The earth’ By Winin Pereira. it’s not all Traditional Indian methods, but there is enough of that in there to warrant a read. I’m also waiting for some large reference books that recorded Indian Agricultural methods from prehistory to Independence. I’ve only located two of the four volumes (medieval to modern times), but they’re on the way now.
      As for my clay, if I was starting from scratch I would double dig, plant rye/beans/chicory and clover, and then revert to an occasional dig/surface cultivation. On this soil, the no- dig method is just too slow.
      All of the best
      Deano

      Reply
  2. Pingback: To dig or not to dig « The Snail of Happiness

  3. Patrick Whitefield

    Hello Deano,

    Another great post from you, as ever combining avid book research with hands-on experience and experiment.

    I particularly appreciate your point about forming a more stable humus by putting some clay in the compost heap. I’ve never thought of this in terms of composting before, though I’ve long appreciated the clay-humus complex in the soil. I’ll start putting soil in the compost myself now. I don’t think those of us with less clayey soils need worry – all soils contain some clay.

    I agree with you about double digging. Although a great advocate of no-dig gardening, I always contend that if a soil lacks humus in the lower layers – and this is true of most soils which haven’t been gardened intensively before – that they need an intensive period of mixing compost in. This usually needs to be done repeatedly for a few years. It’s especially true on clay soils, where downward movement of materials is minimal. On lighter soils you might get away without it. Once you’ve got a dark colour and good structure throughout the soil profile you should never need to dig again.

    But I would part company with you on burning weeds. Not only will you lose the organic matter they contain but also all the nitrogen (and I think the phosphorous – but I’d have to check that). All that remains in terms of plant nutrients are the cations, ie metalic elements such as potassium. Burning brushwood makes sense as it’s hard to use it otherwise – other than in a hugelkultur. Burning herbaceous plants doesn’t. If your main aim is to kill the seeds, submerging them in water should do the trick. I don’t know how long you’d have to leave them under water, but I expect it would a long time.

    all the best, Patrick

    Reply
    1. Deano Post author

      Hi Patrick
      I already ‘drown weeds’, but have never put seedy nettles into a bin before. It might be worth a try to see if that works. I can test it on trays to see if any seeds germinate. I’m not concerned with the nitrogen or the organic matter, I have enough of those. Burning is just a way to recycle the mineral content, and to take some of the fertility away from the weedy areas. The mineral content of wood ash includes 50% lime, 5% Potassium, and 0.5% Phosphorous, which suggest that some/all of the Phosphorous survives the burning process.

      I’m going to try to follow the double dig immediately with winter cereals, beans and clover, to see if I can get roots down into the newly formed spaces, and avoid the hard work a second time. That’s in the next post.
      Wishing you well.
      Deano

      Reply
  4. Pingback: Soil Fertility. Learning from the Past. « The Sustainable Smallholding

  5. Pingback: Dog poo experiments | The Snail of Happiness

Leave a Reply

Your email address will not be published. Required fields are marked *