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!

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