Shortlands Station - Biological Farming

June 2016

David Crutchley has adopted a biological approach to farming his Central Otago property

Over the past 6 years David Crutchley has made the transition from conventional farming on his high country station to a “biological” approach. It has been successful financially and from a production point of view, and he was named Supreme Winner of the inaugural Green Agriculture Innovation (Gaia) Awards as well as winning the “transition” category in the Awards. 

Shortlands Station is 6121ha in the Danseys Pass area of Central Otago and comprises lower dryland, intermediate hill country and high “summer” country. David Crutchley took over from his father in the late 70’s and continued to manage it as a conventional sheep and cattle property. For a time pasture production was successful and profitable, but in the 90’s David realised that grass was getting harder to grow, and eventually the farm ‘hit the wall’, something that he now believes was at least partly due to the change in phosphate rock source from Nauru Island to Morocco, and the much higher amount of acid that was needed to make Moroccan rock soluble as superphosphate.

“Typically we were wintering 10,000 ewes and 300 breeding cows, and come September there was nothing to eat and we struggled to grow anything in October on the lower country during lambing and calving. Then growth would come away in November, but stock had been checked a bit so they weren’t thriving,” he says.

“To me the farm felt quite dead. We were doing as we were told putting on acid-based fertilisers but our pastures were running out. We couldn’t get re-establishment, couldn’t get longevity and I just felt something was wrong.”

“I believed there was huge potential for the central Otago hill country ‘browntop belt’ but we didn’t have the right tools, so we took part in an issues-based monitor farm programme looking at how to develop the lower hill country.”

A field day was held on the property but David was not happy with the conventional advice given, which was essentially to put on more superphosphate and urea and to beware of snake oil salesmen peddling alternative fertilisers. However, conventional fertiliser programmes had not worked in the past, so David decided to talk to every fertiliser sales person who came up the drive.

Most were not able to provide convincing evidence that their products would work, but David was impressed with Bill Thompson from Healthy Soils in Dunedin, who was able to explain what exactly was happening on the farm and how it could be fixed. His explanations tied in with what David had read around the subject of soil management, and so in 2008 the transition from conventional to “biological” farming began.

“First we put a fish-based soil feeder right across our young pastures less than four years old on the flat country. This added microbes to the soil and fed what was already there. We also put on a solids mix that included boron, guano as a source of P, sugar, magnesium and potassium sulphates, sulphur, salt and humates,” says David.

“The soil started to come alive and I noticed that the dung decomposed quickly rather than just sitting on top of the ground in frisbee patches. Those pastures are now nine years old and they are still good paddocks for finishing lambs on.”

“Soil and plant tests showed that we hadn’t been putting on enough lime – we probably used one ton every four years, so we increased that. The net result is that we are growing deeper rooted grass and better crops and I believe they are more nutritious as the stock do well on them.”

“Soil carbon levels are quite low at about 4% but they are now increasing, and as a result we are not drying out as quickly. If you can lift soil carbon by 1%, you retain an extra 144,000 litres of water per hectare.”

Initially David and his son Charles concentrated on the lower flats, but then turned their attention to the hill country. Conventional acid-based fertilisers had proved ineffective so they sent soil samples to the USA to be tested. These confirmed that free aluminium levels were so high as to be toxic to most plants except the Hieracium daisy species, mainly hawkweed, which had taken over in many areas.

MAF research in the 1990’s found that on many soils up to 50% of the P from superphosphate was rendered unavailable to plants within only 10 days of application. However, on high country soils like those on Shortlands Staion the figure is nearer to 100%.

“It looked to me as if the aluminium had reacted with the super and locked the P away, so putting more super onto our soils wouldn’t work and we needed to get the soil biology going stronger,” says David.

“The fish-based soil feeder plus various minerals, based on tests and the advice from our supplier, resulted in suppression of the Hieracium and better pasture growth. Because it really worked, the company started sending people to me but I didn’t know if the results were a fluke because there was no science behind it.   So the company sponsored some trials and I also put a lot of effort in, along with Dr Peter Espie of AgScience, and we came up with some pretty interesting results. We used both high and low fertility sites, low ones that hadn’t been fertilised since at least the 1960’s just to prove we weren’t mining the P, and we got very good results with biological fertilisers and have been able to establish clovers.”

David sent a soil sample to a conventional fertiliser company and their recommendation was to apply 500kg super/ha. In the next door plot they put 40kg/ha of guano along with biological mixes.

“That’s when we got nearly 500 kgDM per kg of P applied off the biological plot and only 27kg off the superphosphate plot. And now when you use a penetrometer on the biological site it moves readily into the soil but the acid/base plot soil has gone hard,” he says. “There was also a palatability trial, and the sheep showed a strong preference for the grass from the biological plot.”

David is also using VAM, a source of mycorrhizal fungi, and Contego BB, a fungus that helps control soil insect pests such as grass grub, to boost pasture growth and help create feed surpluses.

Brassica crops have also benefited from the new fertiliser regime. This season they have received a diverse mix including 10kg of urea plus molasses, humic and fulvic acids, silicon, cider vinegar, fish, selenium, zinc sulphate, potassium iodate, seaweed and phosphoric acid.

“The brassicas now have much stronger root structures that go deeper and absorb more nutrients. We used to have problems with swedes rupturing and rotting after heavy frosts, but because we use only a little urea that problem has disappeared,” says David. “We can now fully feed ewes on swedes and they don’t get any supplement. If I tell people, they think I’m cuckoo, but in our situation that is more economic than feeding fodder beet and having to supplement 30% matter in the form of baleage or hay. People say that it can’t be done but that’s what we do, we are getting such good nutrient uptake.”

One result of the biological approach is a significant reduction in animal health costs down to $2.98/su compared with the South Island Class 2 high country average of about $5.25. Ewes are drenched once a year instead of three times, and lambs are now not drenched until March.

“We have reduced drenching by two-thirds and I’m not sure we should even be doing that much. We still use Provax, we’re getting such good growth rates that pulpy kidney is a problem, and still dip minimally but we don’t get foot problems and have done a lot of work on the structure of our sheep and the cutting percentage of lambs – they have 16% more meat per carcass than the industry average,” says David.

Profitability of the property has risen dramatically because of better dry matter production, animal growth rates and lower health costs, but also because of changes to stock classes and more flexibility in stock numbers. David has analysed the farm using the GrowFARM system to see what stock are most profitable, has removed beef cattle because they were making a loss, changed sheep breed to a Texel X Romney, and now turns over stock rapidly, matching stock numbers more closely to feed availability.

“The critical period used to be in September when we were trying to feed 10,000 ewes and 300 breeding cows through to October when they were lambing and calving, but this September we had only 8000 ewes and 2000 ewe hoggets plus a few trading lambs. Ewes with single lambs are put back onto the mid-altitude country because it is dry, and that helps to create a bigger food bank.”

“We bring in dairy grazing heifers in November/December, and we buy in store lambs too. We identify the annual draft ewes early, they get weaned before Christmas and sent away, so stock that are not required go out quickly, and that leaves more space for lamb trading, and more baleage and silage to be made.”

“By then we’ve got all our crops sown and struck, and that’s basically the pattern – trading lambs and growing them through until the autumn, growing a feed bank. The cows are sourced around December for a winter grazing contract and then they go off in mid August. Come September back down to just the ewes and hoggets.”

David views biological farming as complementary to conventional farming. He is in the business of applying P, N, K and other minerals the same as any other pastoral farmer. However, he applies these elements in different forms and quantities, relying more on the soil biology to make the less soluble forms available to plants.

“I don’t believe in applying the high amounts of acid that come with superphosphate, but I do believe in applying P in other forms. I don’t believe in applying 100 units of urea but I do believe in 10, which I don’t use very often but 10 is all you need to enhance photosynthesis and get production going,” he says.

“However, you shouldn’t go cold turkey into the changes. It’s best to slowly reduce the amount of N being put on each year and work with a company with a trial-proven track record to provide the nutrients that will get the biology going in your soils.”

David’s overall win in the inaugural Gaia Awards has prompted the comment that science supports biological soil practices, and has provided proof of the concept that optimising soil biology leads to increases in dry matter and production and can lead to increased profitability.