Straw / Sheet Mulch Potato Update: SPUDTACULAR!

So its been a crazy month – I’ve missed you all!  We’ve harvested over 1000#’s of potatoes -and sold them- hitting farmers markets for the first time.  There is at least another post of stories there, but for now suffice it to say we love that we have become “the Potato People” in at least two towns and that feels great.

With the farm gardens under control again, I spent a beautiful half hour this weekend working through the Straw Mulch Potatoes that I had put in as a test of deep mulched potatoes (no updates on the towers yet – 2 of the three are still growing and the third blighted so bad I only got 3 spuds for 4 seeds planted).  The Straw Mulch bed had 10 plants, and had been sheet mulched with 3″ of horse manure a year ago, and then got another foot of straw thrown on top as the potato plants grew.  No additional fertilizer, no sprays, and not much irrigation was provided (an inconsequential 10 gallons total from washing out compost buckets).  My hypothesis was that the rich, untilled soil from the sheet mulching combined with the more constant soil moisture provided by the deep straw mulch would help tuber size and plant vigor.  On top of that I was very curious to see if there was any credibility to the claims of increased tuber set from the deep mulch, and how the harvest labor would compare.

First off, I am very pleased with the yield and am convinced (as much as one can be after one test) that super rich soil and deep mulching equates to better yeilds.  Here is my proof:

30#'s of spuds from 10 plants!!!

30#'s of spuds from 10 plants!!!

With an average yield of 3#’s per plant I would be getting 270#’s per row at the farm – a 50% improvement over my current technique – and I was already getting a solid 8.5:1 harvest ratio!   I planted this bed with 4 medium sized Purple Vikings – just under 2#’s.  Yes you got that right – a 15:1 ratio which is near record yields for even conventional farmers.

To put that another way if I can scale this technique up and apply it to my current spacing (3′ rows, 14″ spacing)  I could get 43,500#’s per acre which equates to 18,600,000 million calories.   With the blight coming in growth was stunted and overall tuber size was down compared to what I expect from Purple Viking.  One plant had over 15 potatoes on it – but only a few over 3 oz and most had 8 or more.  If those had sized up to the typical 8oz+ …no I’m not gonna run that math, I’m getting faint from the possibilities!  Sheet mulching an acre will take 400 yards of horse manure – this system isn’t for the faint of heart- but my “base” soil is deader than a doornail so a larger trial at the farm on rich soil will be on the docket for next year.

As others have found, and I have begun to suspect, there was no addition tuber set that I could attribute to the deep mulch – the spuds were located low on the vine as usual, but the soil was evenly moist and full of worms.   Harvest was a breeze, though not as easy as the bucket method – just pull the straw back,  ruffle the moist, rich soil with your fingers, and pluck our spud, after spud, after spud, after spud.  ZERO lost spuds to pitchfork foibles to boot.  As a strip crop between young swaled permaculture tree crops this could be a VERY productive system to pay the bills as the chestnut / orchard comes on line.  Plus from my experience you get a significant net INCREASE in organic matter and it is very close to no till.

Can organic farming feed the world?  Show me a conventional farmer hitting 18,000,000 calories per acre .

FU Monsanto.  You’re Round Up Ready?  Big deal…  this system is Peak Oil Ready.

Be the Change!


PS: Here is a detailed and technical study of straw mulch for potato growing in Germany.  Graphs – oooo shiny!

Compost Trick: 140+ for a week!

Right.  This is likely old hat for many of ya’ll, but after reading some soil books from the seventies (yes, I know I am that dorky) I ran across an anecdote about a biodynamic farmer talking about building his compost heaps and then covering them with straw to act as a blanket.  The epiphany almost knocked me out of my reading chair!  Mulch my pile?  Of course!  It would keep in the water, block the sun to let the bacteria go all the way to the surface, and even keep the yellow jackets off and act as an insulator late in the season!

So I went out, turned my pile (about 30% composted), watered it well, and topped it off with a 4″ layer of wheat straw.  I stuck the thermometer in, and the next morning I was chugging along at 154 degrees.  The next day? 155.  Next? 152, then 150, now 8 days later I am still over 144 with no added water or turning!!  ALL THESE YEARS of watching my compost heat up to 140 degrees after it was turned and watered, only to have it fall off in a week to 100 degrees until I turned it and watered it again I had thought the turning was the important part, but it looks like the moisture was even more so.

Mulch your piles!  Tops and sides too if they are wire.

So Simple!  So Perfect!


Resource Management: Conserve First

The Pimp My Garden push is starting exceedingly slowly – my Real Job got Real Busy and the Great Potato Harvest is taking most of the free time as we harvest and sell 300#’s a week.  Some cool things have happened though, like I was asked to speak on a 30 minute radio show about permaculture a few weeks ago.  In preparation for that I re-read Holmgren’s: Permaculture Principles and Pathways Beyond Sustainability – god is that a great book!  And, as usual, its got me thinking.

Early in the book he is talking through some of the comments that his Design students have made about the choices at his homestead.  In particular, there is no renewable energy component at the property – at least for electricity production.  Anyone that has priced Solar or Wind Power installations knows that to match your current grid power you are looking at $25-50,000 up front, at minimum, for a typical home.  That is a lot of coins.   We are all struggling to allocate our increasingly limited resources as prudently as possible and I loved Holmgren’s approach of choosing NOT to install the electrical generation.  His thinking is this – that $50k would be *much* better spent in other ways.  For much less money he installed a gravity driven rain water catchment system to completely satisfy his household, irrigation, and fire control needs (50,000 gallons), installed wood stoves to supply all his heat and cooking needs (as well as tree groves to supply the wood in coppice management), root cellars to reduce his freezing needs, and also installed day lighting to cut his bulb needs. All told, the changes saved a huge amount of money, and cut their total farm use of electricity to 3 kwh a month.

At that level, should the Oil Run Out he could either build a small steam generator or gasifier to meet his small energy needs, or just as likely he wouldn’t miss the 3 kwh or energy if it was gone as it is only powering luxury items like a refrigerator and computer.  A recent article in the BBC is claiming that the UK may have rolling blackouts in 6 years and that they need to build more energy plants a the cost of hundreds of millions of pounds.  No where in the article do they talk about the critical “nega-watts” of Natural Capitalism fame – the power “created” every time you reduce your consumption as a household, business, or country.  Conservation is carbon neutral, critical to our future and is cheaper to boot.

To take my home off grid with Solar would cost over $50k -and we already use less than 70% of the average household in our area.  For a third that amount I could install a root cellar, hyper effecient appliances, and a masonry wood stove that would drop my energy use another 50-75%.  Switching my desktop to a laptop, ditching the AC and using a whole house fan, and other changes like replacing the carpet with wood floors to ditch the vacuum would be easy and not overly expensive if done as items wear out.  Quilts are cheaper than cordwood anyday.

I guess my point is that we are hard wired as a society to BUILD solutions – add power plants, erect wind turbines, etc.  When more often than not the solution to our problems is in rethinking the root cause of our problem in the first place.  In this case, we don’t need more, we need less.  Likely that is the case more often than not.  In permaculture speak – the problems that we currently face are due to the poor solutions that we currently have in place.  To pepper in the ubiquitous Einstein quote – we need to change our thinking from the mindset that created the problems in the first place if we are to find a workable solution.

Be the change.


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