Dirt Doc­tor

Jim O'Gor­man's meth­ods may be ques­tioned by many, but one only has to look at the qual­ity of the soil on his Kakanui prop­erty, and the crops it pro­duces, to realise he knows what he's do­ing, and he's do­ing it right.

NZ Grower - - NATIONAL FIELDAYS - By: Bar­bara Gill­ham

A lead­ing fig­ure in New Zealand’s or­ganic move­ment, Jim runs his ‘one man’ mi­cro farm at Kakanui with­out the help of elec­tric­ity, or any ma­chin­ery.

Known by many as the ‘Dirt Doc­tor’, Jim be­lieves farm­ers to­day rely too heav­ily on chem­i­cals to ‘fix’ prob­lems with their soil, and says their fo­cus should be on bi­ol­ogy not sci­ence when they are look­ing for ways to im­prove it.

Jim says he was given the name by a lo­cal Brus­sels sprout grower who had dif­fi­culty with a hectare or so of what should have been pro­duc­tive soil. “I helped him use bi­ol­ogy to fix the prob­lem, and his re­sponse was that I had healed the soil and he would call me the Dirt Doc­tor from then on. The name stuck. The name does fit how­ever, as healthy soil in­stead of dead dirt is the aim of the pro­cesses.”

Jim bought his half-hectare prop­erty at Kakanui (North Otago) twenty years ago to estab­lish a School of En­vi­ron­men­tal Re­cov­ery.

An agri­cul­tural sci­en­tist with en­vi­ron­men­tal con­cerns, he says the land, which was cov­ered in Cal­i­for­nia this­tle, was the worst piece of land he could buy.

The prop­erty, which had pre­vi­ously been used for in­ten­sive hor­ti­cul­ture for two gen­er­a­tions, had been cropped al­most con­tin­u­ously for more than thirty years, firstly in bras­sica and fi­nally nar­cissi.

Dur­ing that time, prior to Jim buy­ing it, stan­dard fer­tiliser (e.g. Nitrophosc­a Blue) and chem­i­cal ap­pli­ca­tions, (in­clud­ing DDT and the Tri­azine fam­ily of her­bi­cide, es­pe­cially Sy­mazine) had been ap­plied for dis­ease and pest con­trol.

Neigh­bours de­scribed to Jim how prior to the nar­cissi har­vest, the land was sprayed to “bare brown dead”. A stream of brown was said to flow out of the gate when­ever it rained.

Jim says the ini­tial im­pres­sion was that the land was very dry, lacked sta­ble hum­mus and was packed and hard. A field test re­vealed no worms in ev­i­dence and wa­ter took more than 24 hours to drain away in test holes. A ma­chin­ery-cre­ated hard­pan was ev­i­dent at ap­prox­i­mately 15–20cm depth through­out the prop­erty.

In a pa­per Jim pre­sented at a con­fer­ence at Lin­coln Uni­ver­sity in 2007, he de­scribes the meth­ods taken to rem­edy the state of the soil so it could be turned into a vi­able self-sus­tain­ing or­ganic pro­duc­tion unit within ten years, by us­ing mi­cro­bi­o­log­i­cal hus­bandry and ef­fec­tive weed man­age­ment.

It was de­cided to cre­ate raised beds that are 750mm wide and ap­prox­i­mately 15m long to suit tools he would use. Us­ing what is called “the dou­ble dig” process, the top­soil was bro­ken open with min­i­mum turn­ing, and pulled aside to re­veal the sub­soil, which was then bro­ken open. The next sec­tion of top­soil was then bro­ken open and dragged over the top of the open sub­soil, re­peat­ing the process and form­ing a shoul­der-width bed.

This method, Jim says, in­creased the aer­a­tion of the soil and broke through the hard­pan, in­creas­ing the amount of soil avail­able to crop roots, as well as form­ing paths be­tween the beds to avoid com­paction. With the beds formed, they were then cov­ered with ma­ture com­post. The sides of the beds were then drawn up to mix the com­post with the top few cen­time­tres of top­soil.

The beds were then planted in the sec­ond sea­son and crops were left to grow with a weed bur­den un­til the op­ti­mum time to weed. It was through us­ing this method, and us­ing green waste (in­clud­ing weeds) as com­post, that Jim even­tu­ally turned what was an un­pro­duc­tive piece of land into fer­tile soil with good depth and wa­ter re­ten­tion that it pre­vi­ously lacked.

To­day Jim tries to have 1,000 me­tres of bed un­der pro­duc­tion at any one time.

“I plant so the leaves of the ma­ture crop will be touch­ing other crop plants, this re­duces weed­ing. There are no ma­chines used, not even a lawn­mower, ev­ery­thing is done by hand. This is a part of the de­sign and in­tent to de­velop con­cepts that can be ef­fec­tive with­out ma­chin­ery, in lesser re­sourced sit­u­a­tions.”

Jim has de­signed his small farm around the idea that any green waste should be dug back into the soil, so weeds ef­fec­tively be­come a com­post crop that you are grow­ing at the same time as your veg­etable crops.

Although the soil at Kakanui was orig­i­nally badly dam­aged, Jim has proven that with the right ap­proach it can be turned around and even­tu­ally made pro­duc­tive.

Thanks to his many years spent re­search­ing ways of us­ing mi­cro­bi­ol­ogy to help re­cover dam­aged soil, Jim is a well known and re­spected fig­ure in or­ganic cir­cles, and his pro­duce is sought after be­cause of the flavours pro­duced by the Kakanui soil.

So de­li­cious is his pro­duce, two years ago he was asked if he could pro­vide some for the Duke and Duchess of Cam­bridge’s visit to Gov­ern­ment House, the fourth time he had sup­plied pro­duce to mem­bers of the royal fam­ily.

To­day, work­ing alone on his prop­erty, Jim con­tin­ues to mon­i­tor what is hap­pen­ing in his soil, tak­ing sam­ples and ob­serv­ing im­prove­ments or changes.

Un­til re­cently, few peo­ple un­der­stood the im­por­tant role the mi­cro­bi­ol­ogy of our soil plays in plant pro­duc­tiv­ity. It’s thanks to peo­ple like Jim O’Gor­man and his bi­o­log­i­cal ap­proach to gar­den­ing that this is now chang­ing.

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