Soil matters

A while ago, I touched on the topic of compost.  This is something very close to our hearts, and indeed soil nutrition is absolutely paramount to anyone wanting to produce anything from their land.  In short, you get out what you put in.

I grew up with a father who, while not completely obsessed with his compost heap, was borderline.  I have therefore a moderate level of knowledge of the art of controlled decomposition.  Recent work down here in Costa Rica has given me a few new tricks to add to the repertoire.

Once several cubic yards of material is collected, the process starts by making a soupy mash of yucca (a starchy vegetable) and rice, which is left to ferment under the forest canopy for several days.  When ready, this now frothy soup has been colonized by a variety of decomposer organisms native to the area, and is a powerful inoculant for the compost heap, to kick-start decomposition.

In the shade, a pile is built up of alternating layers of coarse material, green material and fresh manure, followed by a liberal sprinkling of inoculant and molasses diluted 5 to 1 with water.  Repeat this lasagna until all your material is used up.  Cover this heap with plastic, and leave for a week.  Turn the heap, mix and repeat.   Within 3 days the temperature at the core of the heap was 70oC, and within 2 months the heap was finished.

Over the last few years Em and I have had the opportunity to meet and learn from a number of farmers who have been working organically for years, and have managed to actively increase the fertility, productivity and health of their soil.

John Wilcox, the late owner of Duck Creek where we were married, was one such farmer.  John’s formal soil science training at Guelph University provided him with the knowledge to turn a worn out, overgrazed valley bottom into a highly productive little farm.  Similarly, Doug and Jeanette Helmer and family now grow some of the best potatoes (certainly that I’ve eaten) in Pemberton on organically and biodynamically managed land.  Key to both of these farm successes has been cover cropping and practices designed to avoid compaction, structural damage and actively build soil by the continual addition of organic matter.

With our plan to grow intensive vegetables, quite a bit of tilling is inevitable to prepare a seedbed in which we can realistically expect things to grow.  The key is performing this tillage in a sustainable manner for longterm productivity.  Our plan is deep tillage with a spader (one of the most Heath-Robinson farm inventions I’ve ever seen) or chisel plough to avoid bringing subsoil to the surface, and avoid forming a plough pan (a hard, smeared layer of soil at the bottom of the furrow that over time becomes impenetrable to water and roots).  A cover crop such as peas, oats, mustard or warm season grasses like sorghum-Sudangrass is then sown.  The crop is mown and tilled into the soil while still alive, adding nutrients and structure to the soil.

If we manage our cover cropping/ green manure program well, we can tap into a huge resource of macronutrients.  In the atmospheric column above 1ha of land, there is 78,000 tonnes of nitrogen for the taking.  The challenge, as Mr Haber found out, is extracting that and getting it into a form available to plants.  The synthesized method of nitrogen fixation is hugely energy intensive, yet leguminous plants carry this out for us, virtually for free.  Cover crops also act as a “catch crop”, locking up any soil amendments like manure or compost over the winter, preventing them leaching out of the topsoil.  “Peak phosphorous” is another pressing concern, for many people more so than nitrogen, with levels of use of this macro-element rapidly depleting known reserves.

We are lucky in that we are targeting our land search in areas blessed with both family members and friends, but also top-notch soil.   But farmers in drier and less favourable areas have been using no-till practices for years to improve and protect fragile soils.  Today, cover crops are also finding their place in mainstream agriculture with a hybrid of mulched no-till cropping gaining in popularity.  In this method, a cover crop is grown early in the season and rolled flat.  Into this mat is sown the main crop such as corn, soybeans or cotton.  The mulch mat reduces weed pressure, improves water storage and overall soil structure.  In some cases, farmers have seen a 90% reduction in herbicide use.

Several cousins of mine farm grain and sheep in Western Australia. Over Christmas last year we caught up with the Australian side of the family (and Em got to meet them all at once!), and I was stunned when I found out the current costs associated with their fertilizer inputs.  Granted, they operate on a scale orders of magnitude bigger than our plans, but even with economies of scale, the dollars per acre really start to add up.  We have made the decision that we are not keen on heavy chemical use and reliance, and have been tossing up whether to head in the direction of organic certification.  On one hand it would allow us to command premium prices.  On the other, we would have to deal with a heavy regulatory burden and other costs as well as a prescribed list of products we are allowed to use.  Farming organically without certification means reduced yields without the premium pricing to make up for the shortfall.

In addition, we feel that certified organic has become something of a misnomer in many ways in recent years.  Agribusinesses like a certain large Californian company producing salad greens operate on a huge scale, employing technology extremely effectively, but at the same time with fossil fuel inputs at a level that almost negate the benefits of going organic in the first place.

So, we’ve still a lot to think on, but we’re getting there, in this area at least if not in others!

Costa Rica, Coffee and CATIE

Todays take home message: buy Fairtrade if you don’t already.  A lot of sweat, and yes, blood goes into that cup of coffee.  Bear with me here…

On our arrival in Costa Rica back in January, some Spanish lessons were our first priority.  I have travelled briefly in Spain before, but I was thwarted in my efforts to communicate by, frankly, laziness.  Cue much embarrassing mime, pronunciation that made the locals’ skin crawl, and blank staring.  This time I would be a good student. As a bonus, the school that we attended worked with a variety of local organizations that would willingly provide a venue for students wanting to practice, in exchange for volunteer work.  I therefore was delighted to head off to the botanical garden collections and coffee germplasm facility at CATIE, the tropical agronomic research station in Turrialba.

Second only in size to a facility in Ethiopia (coffee’s homeland), the CATIE coffee “finca” is a superstore of the genetic diversity of 2,500 different varieties of coffee from all over the world.  This facility is crucial, as it acts as an insurance policy for the coffee business, providing the ability to breed for resistance to a variety of pests and to develop new strains that will be able to cope with the rapidly changing climate in the latitudes where the “golden bean” grows.

Volunteering at CATIE gave me the opportunity to learn what goes into making great coffee, well before it reaches a barista, while practicing my improving Spanish.  But I hadn’t fully grasped how tricky the rural accent is!  For me the likelihood of coming away from this speaking fluently was going to be like dropping a German on a Newfoundland lobster boat and expecting them to learn BBC English.

While working at CATIE I got involved with a range of the seasonal work involved in growing coffee.  When the bushes are first planted, they are nursed by a crop of Canavalia beans.  Also known as Jack beans, these legumes grow incredibly fast, acting as a nitrogen- and potassium-fixing living mulch, outcompeting other weeds among the young coffee bushes.  Most of the nitrogen for the plants’ early years is courtesy of the Canavalia.


The coffee beans themselves ripen slowly, needing shade, provided here by the Poró tree.   After harvest by hand, the beans go off to be processed – which is another whole fascinating business – and then the plants need to be pruned.  Old dead wood is removed, and the plants are thinned down to 4 or 5 good growing stems from the last years’ growth.  All residues are left to rot on the ground.  At CATIE, their soil pH requires them to lime annually, which also provides a fringe benefit.  By tossing the required dose of powdered dolomite into the canopy of the plants, foliar pests are reduced and there is some foliar uptake of calcium before the rest is washed into the soil with the next rain.

Following this the shade trees need to be pruned to keep them manageable.  Poró is incredibly fast growing with a pulpy, watery wood and vicious thorns.  They are grown as pollards about 8-10 feet high, and every year most of the branches are removed, leaving some for dappled shade while the others grow back.  The branches are hacked off from ladders by machete, chopped up and used as mulch on the ground, breaking down surprisingly quickly despite the girth of some of them.  They also contain a lot of native bees’ nests.  I pretty quickly learned to sprint away through a minefield of brush and stumps!

Add to this a constant cycle of mowing in the organic crop and spraying weeds among the conventionally grown plants and you have yourself a pretty busy year.

Now, a razor-sharp machete is the tool of choice for your average work day on a coffee farm.  It is a versatile, highly efficient tool that, in skilled hands, performs jobs ranging from tree pruning to tooth pick.  What it also is, in less skilled hands, is a rather messy means of not only trimming your thumbnails, but also a small portion of thumb itself.  While pruning a bush one morning with my mind elsewhere, the inevitable happened.  The missing piece of thumb-meat was gone and would provide a good protein source for the ants, so I dripped my way over to Luis the foreman, and explained in my finest Spanish what had happened.  The long and the short of it is that having been patched up, they kept me away from machetes for a while.  They reckoned I could be trusted with a spade at least, and so I was re-assigned to their compost program. This turned out to be a great blessing in disguise; some more about that another day.