My potato experiment

Discussion in 'Planting, growing, nurturing Plants' started by IntensiveGardener, Jun 28, 2007.

  1. IntensiveGardener

    IntensiveGardener Junior Member

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    Last summer I decided to experiment with different methods of growing spuds.
    I live in Trentham, Victoria and have plenty of land. This area is considered to be one of the best areas for growing potatoes and Trentham was built almost entirely by spud farmers. Many locals are decended from irish immigrants.

    I chose a garden bed of approximately 300 square feet and divided it in 3, 100 square feet for each method. The soil was relatively rich and about 1 foot deep over a red clay pan. Soil is acidic (5.5Ph)
    I aimed to determine which method would yield best in terms of labour input, fertilizer cost, water use and compost input.
    I used seed potatoes purchased from a local grower, and of a local variety (coliban)
    Each area got the same water, about 3 or 4 good soakings throughout the summer plus rainfall.

    Method A: Conventional
    I tried as much as possible to mimmick local commercial methods, although I use hand tools and much less water. I lifted the soil with a fork then made 3 furrows about 6” deep in which to plant. I placed spuds in furrow and covered with soil, then hoed between the rows using a draw hoe until the plants were big enough to shade out weeds. Organic fertilizer was sprinkled over the bed, I used dynamic lifter.

    Labour: 3- 4 hours for preparation plus maybe 4 hours of hoeing throughout the summer ( ½ hour per week for 8 weeks). All up about 8 hours work.

    Fertilizer: maybe $5 worth

    Method B: Permaculture
    After hearing almost every local hippy I know talk about no dig spud growing I tried it. Some of the claims which were made were; potatoes will break up the hard pan underneath, After growing spuds the soil will be rich in N, Spuds clear the soil of pests.. etc…
    I placed the seed gently into the topsoil then covered with freshly cut clover, wheat straw and lawn clippings to about 25 cm deep
    I also used about 1” of compost.
    Labour: 1 hour planting, 2 hours cutting the clover and lawns and approximately 2 – 3 hours for making the compost. All up about 5 hours work.

    Straw cost me about $30

    Method C: Intensive
    I deeply trenched the soil, placing seed at the base of each trench then covering with the next foot of topsoil. I broke up the hard pan at the base with a fork. Once planted I added 1” of compost and 2” of straw mulch.

    Labour: 4 hours for digging and planting. 2 – 3 hours for compost making and ½ hour for applying it to soil. 1 hour of light weeding for weeds that came up through the straw.
    All up: 8 ½ hours
    Straw cost about $ 10

    Results:
    A: Conventional:
    After repeated warnings from local farmers that I was not watering enough to get a crop I was pleasantly surprised to find medium sized potatoes at the end of season. Locals water their spuds for 4 hours per day, all summer, rain, hail or shine!!!
    Most spuds were ok but some had scab, maybe because of contact with the fertilizer. Some were also damaged by the hoe or green from being too close to the light. The spuds were a little dry in taste. The soil underneath was still heavily compacted at end of season with 95% of spuds in top foot.
    Total yield: 30 kg
    Edible yield: 22kg
    Edible Yield per hour of work: 2.75kg

    B: Permaculture:
    I was rather disappointed with these results. There were plently of spuds of a variety of sizes, some were very large. All were of very odd shapes however.
    I’m not sure why but much of the crop from this area was infested by a combination of scab and potato worms. The soil underneath was still very compacted although the topsoil was obviously enriched by the mulch and compost. Potatoes did not grow down into the subsoil as I had been lead to believe. Their were no green potatoes. While growing the plants did not look healthy.
    Total yield: 35kg
    Edible yield: 10kg!
    Edible yield per hour of work: 2kg

    C: Intensive:
    When digging these potatoes I was amazed at the quantity. All were very good size and there was minimal disease and pest damage. Most spuds had a healthy shape. Lifting these potatoes took me about twice as long as with the other two methods. The soil was very rich and dark to a good depth. No clay pan remained. I was able to follow this crop with a legume crop without any serious work or fertilizers except lime. 
    Total yield: 305kg!!
    Edible yield: 280kg
    Edible yield per hour of work: 32.9kg


    Clearly only one of these methods is a commercially viable alternative to tractor grown spuds, even if you include harvesting time. Harvesting the spuds from methods A & B was a waste of time. The intensive method is also the one which used the least fossil fuels to grow/transport straw or fertilizer. Anyone know why the permaculture experiment didn’t work so well? I used “disease free seeds”.
    I’d be happy to repeat this experiment again next season if anyone has any tips or wants to see pictures. People often claim that they don’t have the time to do Method C. I suggest planting half the area, you’ll still get more spuds.

    I might add that my compost is made very simply by piling up weeds, manure, soil, etc... No turning is done. The compost takes 6 months to mature. If your patient with it its much less work.
    Cheers,
    I.G
     
  2. Logos_Flame

    Logos_Flame Junior Member

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    My guess is that the hardpan needs to be broken up, and the soil worked for a bit, as you did in the "intesntive" method. Once the soil is broken up, and some good compost is worked into it, then in the future you may be able to use the less labor intensive permaculture method. So, perhaps after a few more go rounds with the intensive method, the soil will be healthy enough to do less labor intensive methods. Healthy soil requires lots of bacteria activity, and hard packed, dry soil does not lend itself to this. Once the soil is broken up, and the bacteria population is beefed up via the addition of compost, then it can cruise along with less help.

    Another thing to do is to start a worm factory. Feed your compost and other organic matter, along with some lime, to the worms. Then you can use the worm casting as wonderful fertilizer, also as the worms multiply you can add the extra worms to your soil which also help break up the hard pan and their casting feed the bacteria.

    Those are some thoughts anyway.

    Thank you for posting this experiment, it was very interesting to read.
     
  3. ho-hum

    ho-hum New Member

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    Intensive

    Great experiment.

    From your section B. This would in fact require a high degree of nitrogen, which it would draw from the soil, to break down and apart from water retention and weed supression it would have a negative impact on the potatoes which would be reflected in the yield.

    This was done in section c. Of all the amendments and processes you perfromed this was by far the most valuable thing you did and would reflect hugely on yield by allowing the potato plants roots to reach deep into the soil.


    I have repeatedly stressed in here that the two best things you can do for soil it to allow access to air and water. It has an impact on all soils types except pure sand. I do this by using a garden fork and had a homemade version of one of these contraptions for a while [till stolen].

    https://www.allsun.com.au/BroadForkL.html

    Mine had 4 long tines and it allowed great penetration and aeration. I dont like to dig or turn soils over. I fork the soil then scratch the top with a hoe or cultivator, sometimes a steel rake is enough to produce a seed bed for small seeds like carrots etc.

    I use the fork to lift the soil till it cracks and sometimes on our compacted clay loams I would have to water the soil and go back a second time. This allows the surface type microbes to get deep into the soil profile, which is where we want them.

    I have often read about potatoes 'breaking the soil up' and disregarded it as largely myth. What would break the soil up is the pre-planting preparation and the harvest process.... :D

    floot
     
  4. hedwig

    hedwig Junior Member

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    great experiment!!
    perhaps you should do the same in successive years to see hoe things develop.
    You are gardening like a Uni!

    Were do you live? Which climate/soil?
     
  5. Jez

    Jez Junior Member

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    G'day IG,

    Spuds will break up clay and condition soil a bit (personally I think sweet potato does a better job), but only to a point. If it's genuinely tough hardpan you'd either need to break it up, or build up a lot more growing medium on top of it to avoid them running into it. You can use claybreakers like comfrey and lucerne in shallow no-dig beds to do some remedial work and conditioning.

    I don't really agree with whoever told you that spuds clear the soil of pests...like tomatoes and other nematode prone crops, it's an uphill battle if you keep planting them in the same spot repeatedly (as I understand they're finding out in Idaho lately - very bad potato worm breakout).

    Have you seen the spud patches of some of these 'hippies' - might provide you with a few answers if you can identify the differences?

    Was the "minimal pest damage" from control group C also potato worm? If so, I guess it's possible that section A was on soil that didn't have a potato worm presence, while the other part of the bed did and they preferred to attack the stressed out spuds in group B.

    FWIW, IMO it'd be a good idea to rotate a few years of crops which aren't nematode prone through the whole area before planting a nematode prone crop in that bed again - asparagus is a good perennial which they find toxic and should drastically reduce their presence.
     
  6. bovine_blue

    bovine_blue Junior Member

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    Jez

    I also heard that the onion family helps to kill them off. Is that true?
     
  7. Jez

    Jez Junior Member

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    I honestly don't know bovine. They may well be, I just don't recall coming across that info.

    Marigolds are often touted as great for combating nematodes, but other material I've read suggest it takes at least 4 months for their roots to begin taking effect, or that they have to be dug whole through the soil before doing any good.

    Neither option seems much good for annual crops. :wink:

    It's maybe a case of we humans still not really knowing that much about what goes on under the soil?

    I've never had a nematode problem (touching wood :wink:)...maybe I've just been lucky, maybe it's got something to do with the fact I take a lot of effort to build good soil prior to planting and seldom plant in blocks or rows of the same crop.
     
  8. sweetpea

    sweetpea Junior Member

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    IG, great experiment, good for you for keeping such good track, and interesting results.

    My only thought is that permaculture is not something that you walk up to unimproved soil, put layers of organic material on top and say it's permaculture.

    permaculture beds need to be prepared at least a year before on nonpermaculture soil with some kind of green manure clovers or green cover crop, their deep roots do break up the hardpan over the year. When the clovers die back, then layers of paper, compost, straw, coffee grounds, leaves, etc., stacked, kept damp, possibly covered by tarps in a drought, and left to rot and bring in worms and soil critters for at least 9 months, and all through winter, adding as necessary to keep at least a 6" layer working all the time.

    Then when spring comes, pull back those layers of mulch and you've got soil that's ready for a permaculture experiment.

    I think if you keep composting/leaf mulching your permaculture patch, and grow it again using permaculture methods next season, you will see some amazing results with less water. In fact, it would be interesting to do the same experiment next year and see if the results in the other two sections have changed or stayed the same. :)
     
  9. Peter Warne

    Peter Warne Junior Member

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    Great discussion, thanks to IG for sharing this inspiring experiment, and to Floot for his suggestion of that deep soil moving fork, and Logos Flame, Sweetpea and Jez - I've probably still forgotten someone. Floot's description of that fork has inspired us to buy one from the Gundaroo Tiller people. We have grown potatoes using the permaculture/no dig method, and we've had mostly disappointing results, even when we did it in a fallow corner of the chicken run. WE're going to work over a patch with that new fork when it arrives, and see what a difference it makes.

    Great stuff.
     
  10. sweetpea

    sweetpea Junior Member

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    You know, after thinking about it, I don't believe I've ever seen using just mulches and no soil over the tops of potatoes, and I'm not sure that the definition of Permaculture is growing things in clover/straw mulches without the addition of soil. At least I wouldn't define it that way.

    Permaculture improves the soil by using mulches as a surface layer only, that break down and get incorporated into the soil. The top layer of mulch is just a mini working pile that holds moisture and contributes a very slow addition of compost tea and eventually compost.

    It looks like the results show that method 1 and 3 both put soil over the potatoes and got better yields, which is what potatoes need to develop in.

    My family has farmed back for many generations, always using leaf/straw mulches, which is where I learned about it, and that always involved pulling back the top mulch to add any soil or improvements, and then putting it back into place, like tucking everything in. That's how I grow potatoes, and have gotten fine yields without diseases. I do have to look out for the expanding potatoes exposing themselves to sunlight and earwigs, critters that might chew on them, but those are always covered with a soil/compost mix. I have relied on the humus in the compost to do a lot of protecting of root and tuber vegetables.

    Has anyone else heard that intensive methods seem great the first year, then tend to peter out after that, creating a new layer of hardpan under the one that was broken apart?
     
  11. richard in manoa

    richard in manoa Junior Member

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    Sweetpea, yes I've heard that repeated tilling to a certain depth over the years will create a hardpan. I think it is especially common with mechanical tillers, since the depth settings can be more or less precise.
    Of course, if you are always adding lots of organic matter and using mulches wyou will promoting lots of microorganisms and bigger things like worms which should do a lot open up the lower levels I would have thought...
    That deep, broad, many tined fork looks pretty ace, doesn't it? I wwoofed on a farm where they used one of them, along with their John Jeavons inspired intensive methods.

    As for Permaculture advocating only one method of potato cultivation - well, this misses the point. Bill might well outline no-dig methods of growing potatoes in tyres or straw or whatever - but he also says that this is appropriate for some people in some places. He also says that if you are young and full of energy, go ahead and dig over your garden beds!
     
  12. IntensiveGardener

    IntensiveGardener Junior Member

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    Thanks for all the interesting responses everyone.
    I will definately do this experiment again next year.

    I take the point that without improving the soil a bit first its a bit unfair to the conventional and permaculture methods while the intensive patch enjoyed deep, well composted soil from the start.

    The soil was farily good at the start being origionally ploughed from my best paddock of pasture. I only ploughed to the depth of the topsoil however (hence the hardpan) because i wanted to avoid mixing the soil layers as much as possible.

    I also think that double digging it like that was the best thing i did floot. Worked wonders for other crops too. Digging it like this and adding a bit of compost is the fastest way i'v found of improving my soil.
    I tend to follow john jeavesons biointensive method Richard. Its very hard at first but gets much easier after the initial digging. I'v also used a fork like that. Jeavson calls it a U-Bar though he reconends double digging it initially then using the fork after that.

    Next year i will try the experiment on deeper soil and see if i can improve the yeilds.
    I think maybe the intensive method works well because the spuds are planted really deep in really loose soil. (lots of air and water)


    I do rotate crops and won't grow potatos in that spot for a long time. There are broadbeans there now.
    I rarely plant spuds on land which has been heavily limed for a previous crop


    :)
    I'm trying to make it commercially viable and also prove that organic gardening is not only more ecological but also more efficient in terms of land, water and energy use. One of the ideas of the biointensive method is that you can increase yeil dramatically by adding only a little more labour.
    I'v got way too many garden beds (33, 400 Square foot) so i use other methods too.

    Hedwig,I live near Daylesford in Victoria. The soil is based on red volcanic clay with choclate brown topsoil when good. Its fairly acidic (5.3) but rich in minerals and has a lot of potential
     
  13. sweetpea

    sweetpea Junior Member

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    IG, wow, volcanic soil, you've got a real goldmine there. I have been trying to do amendments to my soil to emulate volcanic soil because of the great minerals available there. I can't help but think that with the additions of compost and top mulches you will see really great results.

    So you've got 3/4 of an acre, all in annual vegetables? What other methods are you using? Have you started adding charred carbon? I have a friend doing it commercially and he's getting really amazing results when using mulches and organic farming methods.

    Richard, yeah, I absolutely agree that organic matter will help with the soil structure. I think I even read that any digging, even with a fork or shovel will create a hardpan layer. I have clay soil that you could make pyramid blocks out of, and the thought of that scared me so much, I stopped digging and started using clovers so their deep roots would help out in that regard.

    I didn't mean to imply Permaculture advocated only one method, just that I'd never seen the method of growing anything in just mulches that were newly placed and not yet broken down, at least partially, being called Permaculture, especially for something like potatoes that really do need soil all around them.

    In fact, we probably use the word Permaculture in ways that are not even close to the originally intended meaning. I know sometimes I'm really only using organic farming methods that are a small part of Permaculture :)
     
  14. IntensiveGardener

    IntensiveGardener Junior Member

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    my gardening methods

    Yeah, definately. It doesn't take much to get my soil into good condition fairly quickly. The main obstacle is the hardpan but i'm slowly fixing that both manually (when i need to use the land quickly) and with plants. It gets very cold here in winter and not many good vegies will grow. I'm limited to spinach, broadbeans, brassicas and onion family. I'm using broad beans, lupins, oats and barely to deepen the soil during winter.

    I'v actually got about twice that area ploughed but the other section has very little organic matter and is not dug into beds yet so i'v just planted clovers there for now to slowly improve it. :)

    Its not all anual vegies but i tend to think that if i get the soil good enough for caulis or snowpeas and then plant my perenials after that it will be better in the long run. Its an ideal climate here for most soft fruit so i'm aiming to plant a bed each of raspberries, strawberries, Blueberries and silvan type blackberries, maybe some currents too. Other perenials i'm planting include asparagus and perenial fodder crops like lucern, a couple of rows of tree lucern ( for the cows to turn into manure), some mints and comfrey.

    I use differnt methods for different things. For most vegies i prefer to do the intensive way plus some mulch to save water because the results are so amazing. Obviously i don't have the time to double dig before the broadbeans or grains etc...
    For the perenials like cane fruit and trees i want to grow a clover understory in the bed for nitrogen and organic matter. (not with blueberries)
    On going soil prep for vegies will be more like minimum dig with compost unless it really compacts again. (unlikely with enough compost/OM) i lightly sift the compost into the top 2 inches rather than just putting it on top. I use lime and wood ash (containing charcole) as both soil additives and in the compost in small doses. I also use shell grit as i think it will replace the need for lime in the long run.

    I'v got a rotary hoe but prefer not to use it. I use it sometimes for the prep for grains or on land overgrown with weeds but wouldn't dream of using it on well structured soil.


    I never dig unless i'v got ample compost to add in the process or some good bulk organic matter as an alternative. Digging destroys structure and u need something to feed the soil life so they repair it. If not digging can be very bad and cause hard pans, erosion etc...

    I also find that a little good compost structures the soil better than lots of bulk stuff.

    What amendments are you doing to emulate volcanic soil sweetpea? What did u have to start with?
    Re-mineralising it with lime, shell grit, rock phos, granite or whatever your soil needs + enough organic matter will always work wonders provided its done right.
     
  15. IntensiveGardener

    IntensiveGardener Junior Member

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    ongoing intensive method.

    I have also heard that sweetpea but i think its due to either not enough compost, using the wrong rotation/mix of plants or both.
    Prodived you grow a deep rooted plant like broadbeans, peas or grains every now and then or in amoungst others and add at the very least 1/2 an inch of good compost at least once per year this shouldn't occur.
    In the biointensive method often they double dig the soil every few crops, adding compost each time. The residues of the previous compost fall down into the deapths of the soil like during a landslide. The soil should get deeper and deeper and the crops yeild and quality improve over time.
    I'v got a few small intensive beds which i'v been doing like this for over 10 years. They're now becomeing a herb garden because of my new huge garden. The brown topsoil is about 2" deep and the red clay under is not compacted.
    I am admittedly young and full of energy though :)
     
  16. ali_celt

    ali_celt Junior Member

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    thankyou for posting this, i find it really interesting.
    I was going to do "potatoes under straw" following the instructions that i have on a 'Gardening Australia" video - Peter Cundall does a patch of potatoes directly over lawn, by laying down thick newspaper and sucessive layers of straw, sheep manure and blood and bone fertiliser.
    He seemd to have a reasonably good yeild from doing this.
    Would this be different to the method you described in B because of the straw and manure content?
    Ali
     
  17. IntensiveGardener

    IntensiveGardener Junior Member

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    Ali,
    This method is very similar to the one i used in the no dig experiment. I used compost, lawn

    clippings, straw and other things in my mulch. No manure but the compost had cow and horse manure in it.
    I assume the yeilds peter cundle gets are better because of
    1. His lawn probably had a better structure under it than the ground i used. It probably didn't have much of a hardpan.

    2. His soil may have had less pests in it.

    Certainly a good way to turn lawn into gardens, the potatoes are just a bonus so even smaller yeilds are fine in this case.

    If anyone has the time/energy and compost i would certainly recomend double digging and placing the

    seeds in the trench. The crop was enormous, and the soil afterwards was dark, rich and very fine. (not many clumps left at all.) Don't do it without compost though. this will create a much deeper soil much more quickly than the no dig method.
    IG
     
  18. gardenlen

    gardenlen Group for banned users

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    g'day ali,

    no need for newspaper, see our pics of how we do potato's we get good returns.

    those same test results mentioned may return totally different results in another situation how things grow for anyone person at anytime could be variable depending on conditions, and land aspect, rain and sunshine all come into it along with natural soil fertility and plant varieties, too many variable for anyone outcome to be more than a guide.

    what we do works for us, the fun part of gardening is finding out what works for you.

    like a gardener did a test to show that grey water could be less than beneficial they got the results they wanted because that is the law of nature anyone who sets up a test gets the desired results, nothing beats working out how to make things work.

    len
     
  19. IntensiveGardener

    IntensiveGardener Junior Member

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    len wrote:
    Definatly. The intensive methods i use are not for everyone. Not everyone is a fit, young, or has heaps of energy. Although it was my 50 year old father who showed me this method, which he still uses.
    With respect len i do not do my experiments to prove a predetermined point. I have always done my spuds by the biointensive way and got good yeilds.
    Obviously this method is very hard work and takes longer than other ways.
    When a few different permies i met described their method i decided i'd give it a go and compare the results. I'd be very happy if i could get the same yeilds from a lower labour method.

    I'm planting to repeat the experiment in the comming season with some improvements to methods A and B.
    I'v got bed which is currently growing straw (barely) which has been worked before to 2 foot deep. After the straw is done (october) i will divide the bed in 3 and plant. The bed has never grown potatoes before.
    Other than what i'v already done does anyone have any suggestions as to how i can improve the yeilds/quality of the no dig and traditional methods?
    cheers,
    IG
     
  20. sweetpea

    sweetpea Junior Member

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    IG, what nutrient additions is that straw going to add to the soil? And although it will have pulled some minerals out of your soil, it would take a good few months under the right circumstances to break down and put what it has to offer back into the soil, so you'll need to add almost everything you need if you are planting in October.

    BTW, maybe I missed it, but where are you?
     

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