What lies be­neath

Element - - Planet - GRAEME SAIT New Zealand-born author and ed­u­ca­tor Graeme Sait is CEO of Aus­tralian com­pany NTS. He trav­els the world train­ing farm­ers, con­sul­tants and med­i­cal prac­ti­tion­ers in the im­por­tance of nu­tri­ent dense, medic­i­nal food and the strate­gies to pro­duce t

Healthy soils are the ba­sis of all life on land and the es­sen­tial build­ing blocks of sus­tain­able farms and nu­tri­tious food.

Afew weeks back, while hav­ing my hair cut at a lo­cal salon, I was asked about my pro­fes­sion. I said that I taught farm­ers around the world how to grow with less need for chem­i­cals. I ex­plained that I was con­stantly re­search­ing the links be­tween soil health and hu­man health, with an em­pha­sis upon the im­por­tance of nu­tri­ent-dense food. The hair­dresser re­sponded: ‘What has the soil got to do with food?’

The price of de­ple­tion We are what we eat and what we eat comes from soils that are a shadow of their for­mer selves. The loss of min­er­als, mi­crobes and hu­mus from our soils has ne­ces­si­tated ev­er­in­creas­ing lev­els of chem­i­cal in­ter­ven­tion which has, in turn, fur­ther ex­ac­er­bated the losses. It is the prover­bial vi­cious cy­cle and un­for­tu­nately we are the big losers in this equa­tion. The sus­tain­abil­ity of con­tin­u­ing down the cur­rent path is ques­tion­able. This is best il­lus­trated by the fact that we have used more chem­i­cals ev­ery year since we be­gan the “chem­i­cal ex­per­i­ment” in agri­cul­ture (ten decades of ex­trac­tive farm­ing) and yet ev­ery year there has been a global in­crease in pest and dis­ease pres­sure. Last year was a record year for chem­i­cal us­age around the globe (in­volv­ing a 14% in­crease) and this sig­nif­i­cantly eclipsed the pre­vi­ous year, which was also a record. Dows­ing our soils and food with more chem­i­cals each year, with less and less re­sponse, is surely the def­i­ni­tion of un­sus­tain­abil­ity.

What de­ter­mines a healthy soil? The cor­ner­stones of a highly pro­duc­tive, dis­ease-re­sis­tant soil, as pre­vi­ously men­tioned, are min­er­als, mi­crobes and hu­mus.

Min­er­als are the plant’s build­ing blocks for the phy­tonu­tri­ents (vi­ta­mins, carotenes, an­tiox­i­dants and pro­tec­tive com­pounds like sul­furo­phane, ly­copene and an­tho­cyanins) that de­ter­mine medic­i­nal qual­i­ties in fresh food. The avail­abil­ity of min­er­als to plants is de­ter­mined by sup­ply, bal­ance and bi­ol­ogy. For decades, we mined min­er­als from our soils through crop re­moval and only re­placed three or four. We also ig­nored the bi­ol­ogy that de­liv­ers th­ese min­er­als and pro­tects the plant. We reg­u­larly as­saulted soil life with salts and bio­cides and rarely re­placed or nur­tured those that re­mained. How­ever, it is more than the sim­plis­tic, ni­tro­gen, phos­pho­rus, potas­sium (NPK) ap­proach and ne­glect of bi­ol­ogy which has im­pacted soil health, min­eral de­liv­ery and as­so­ci­ated farm prof­itabil­ity. No min­eral is an is­land and each min­eral im­pacts sev­eral oth­ers. It is all about bal­ance.

The Goldilocks fac­tor

The start­ing point in the bal­ance equa­tion is al­ways cal­cium, the trucker of all min­er­als. Whether you are a pri­mary pro­ducer or a home gar­dener, your first pri­or­ity is to lime up to your soil’s cal­cium re­quire­ments. Each soil has a dif­fer­ent cal­cium stor­age ca­pac­ity based upon its clay com­po­nent. A good soil test will pro­vide base sat­u­ra­tion de­tails (the per­cent­age of stor­age space avail­able on the clay col­loid) and an as­so­ci­ated in­di­ca­tion of ap­pro­pri­ate cal­cium ap­pli­ca­tions. An un­der­stand­ing of this bal­ance is

“Hu­mus holds its own weight in wa­ter and a sim­ple in­crease of 1% or­ganic mat­ter (hu­mus) con­fers 170,000 litres of ex­tra wa­ter stor­age per hectare.”

es­sen­tial be­cause over lim­ing can ac­tu­ally be worse than ig­nor­ing cal­cium re­quire­ments. It is all about get­ting it ‘just right’, hence the Goldilocks anal­ogy. An over­sup­ply of cal­cium can neg­a­tively im­pact the up­take of seven other min­er­als. The cor­rect amount of cal­cium in re­la­tion to mag­ne­sium (the Ca/Mg ra­tio) ef­fec­tively de­ter­mines how well a soil can breathe and this im­pacts ev­ery­thing. An open, breath­ing soil fa­cil­i­tates im­proved pho­to­syn­the­sis (the most im­por­tant process on the planet) and pro­vides the op­ti­mum ter­rain for earth­worms and other mem­bers of your aer­o­bic, mi­cro­bial work­force. Plant roots ex­pand unim­peded in this medium and mois­ture moves in freely from above and be­low.

So, it is cal­cium as a start­ing point, and then all other ma­jor and mi­nor min­er­als that need to be ad­dressed for high pro­duc­tion fer­til­ity. Zinc for leaf size (the so­lar panel), cop­per for re­silience, boron for re­pro­duc­tion, molyb­de­num and cobalt to ac­cess free ni­tro­gen from the at­mos­phere and sil­ica (for the cell strength that helps the plant re­sist both dis­ease and in­sect at­tack) In con­cert, a good sup­ply of th­ese and other min­er­als will en­sure healthy live­stock, healthy hu­mans and a healthy planet. When we in­clude plan­e­tary health in the equa­tion we are now talk­ing about the third, and most im­por­tant cor­ner­stone of soil health, hu­mus.

Hu­mus saves the world

Hu­mus is the sweet smelling, choco­late-coloured sub­stance that is pro­duced by mi­cro-or­gan­isms and serves as their home base. This prod­uct of de­com­po­si­tion is the soil glue that de­ter­mines whether our streams run brown fol­low­ing rain storms, but it is also the stor­age sys­tem for min­er­als and mois­ture. Hu­mus is the only stor­age medium in the soil ca­pa­ble of latch­ing on to all min­er­als, in­clud­ing the highly leach­able ni­trate form of ni­tro­gen. Hu­mus holds its own weight in wa­ter and a sim­ple in­crease of 1% or­ganic mat­ter (hu­mus) con­fers 170,000 litres of ex­tra wa­ter stor­age per hectare. The New Zealan­ders who have nur­tured soil bi­ol­ogy and in­creased hu­mus lev­els saw the ob­vi­ous gains of their strat­egy dur­ing the re­cent de­struc­tive drought. Hu­mus pre­vents ni­trate leach­ing, cleanses soil con­tam­i­nants and houses the preda­tory or­gan­isms and mi­crobe ex­u­dates that pro­tect plants from pests. How­ever, the most im­por­tant “un­der­stand­ing” in re­la­tion to hu­mus re­lates to re­vers­ing cli­mate change. When we build or­ganic mat­ter in our soils, we are in­ter­ven­ing in the car­bon cy­cle and se­ques­ter­ing CO2 from the at­mos­phere. This CO2 se­ques­tra­tion is ac­tu­ally the only way we can ef­fec­tively ad­dress global heat­ing within an in­creas­ingly small time­frame. Please check my TED pre­sen­ta­tion on YouTube for more de­tail. Just Google: “Graeme Sait TED”.

How do we re­gen­er­ate our soils?

Min­eral bal­ance, in­ex­pen­sive mi­cro­bial in­ocu­lums and com­post are three keys to im­prov­ing prof­itabil­ity, plant re­silience, stock health and our health.

The mi­crobe most miss­ing in most soils around the world is ac­tu­ally the most im­por­tant crea­ture of them all at this point in time. My­c­or­rhizal fungi bur­row into the plant roots and then cre­ate a mas­sive root ex­ten­sion that ef­fec­tively pro­vides ten times more root sur­face area. Th­ese sym­bi­otic fungi al­low the plant greater ac­cess to key min­er­als like phos­pho­rus, potas­sium and cal­cium and they pro­duce im­mune sup­port­ing bio-chem­i­cals for their host. They also pro­duce a sticky sub­stance called glo­ma­lin that is now known to be the trig­ger­ing mech­a­nism for 30% of the hu­mus in the soil. Ex­trac­tive agri­cul­ture has done more than in­crease our like­li­hood of grow­ing sub­stan­dard, chem­i­cally con­tam­i­nated food, it has also knocked out 90% of the all-im­por­tant my­c­or­rhizal fungi in our soils. Th­ese crea­tures can be rein­tro­duced for as lit­tle as ten dollars per hectare and we need to ini­ti­ate this re­pop­u­la­tion ex­er­cise, yes­ter­day.

Com­post­ing needs to be­come the mantra for ev­ery food pro­ducer, home gar­dener and coun­cil. Com­post­ing in­volves hu­mus pro­duc­tion and the ad­di­tion of com­post to the soil sparks fur­ther hu­mus cre­ation by re-en­er­gised soil life. It is now time that we re­visit the an­cient wis­dom that de­fined the words “hu­mus” and “hu­man” as the same thing. Both words mean “of and for the earth”, with the pro­found im­pli­ca­tions of that un­der­stand­ing.

Photo: Ted Baghurst

Hu­mus, worms and deep roots; the signs of healthy soil.

Be­fore and Af­ter This veg­etable gar­den was pro­duced from a piece of kikuya lawn at a one day work­shop on Nor­folk Is­land. Com­post, lime, mi­crobes, min­er­als, hu­mates and mulch were ap­plied and it was planted in seeds and seedlings. The ‘af­ter’ photo is the same plot ex­actly four weeks later.



ZZ2 in South Africa is the South­ern Hemi­sphere’s largest tomato grower, and is now farm­ing 90,000 hectares bi­o­log­i­cally. This dis­ease-free tomato crop is grown on their own com­post, hu­mates, my­c­or­rhizal fungi and fo­liars.

Pas­ture crop­ping: The bi­o­log­i­cal con­cept of ‘’pas­ture crop­ping” into dor­mant win­ter pas­ture pro­vides ex­tra feed and pho­to­syn­the­sis. Re­search has shown that is a pow­er­house, hu­mus-build­ing strat­egy.

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