Day 45 – More Pasture Cropping

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Reality check.

Angus Maurice is a friend of Colin Seis, and spent over 5 years training people how to implement Pasture Grazing on their own farms. He also taught “No Kill” farming, which is similar to Pasture Cropping, but more extreme. It uses no chemicals at all, and also stipulates the cash crop must be drilled with a disc opener machine, so that there is minimum disturbance.IMG_3991The problem is, he now doesn’t really believe that it works. You can’t say he hasn’t tried, after 7 years of continuous Pasture Cropping and a field that he has left in the system now to see what happens in the even longer term. What Angus finds is that crop yields are just too badly effected – he reckons on average they will produce only 50% of a conventional system. This is obviously a huge drop, and the slight increase in grazing income, plus the reduction is crop growing costs, does not get anywhere near to making up the difference.

As I mentioned, there is one field that has been left in Pasture Cropping, and this year it is growing spelt. It had been attacked by insects earlier in the season and had some pretty big bare patches; however Angus did not believe that was due to the cropping system. But there was no denying that this field looked significantly worse than his conventionally cropped land. It was uneven, and looked at least 3 weeks behind. he is anticipating it will yield half as much as the other fields. It must be said that one difference here is that the fields were drilled with a cash crop every year, rather than once every 4-7 years as at Colin’s farm. Angus says he has tried all different techniques – high inputs, low inputs, but nothing makes it work. He puts this down to competition from the “dormant” grasses for moisture and nutrients.

Angus no longer works as a Pasture Cropping educator.

Angus grows spelt, which yields around 40% less than wheat, but sells for twice the price. It also gives good grazing for his sheep in the winter

Spelt yields around 40% less than wheat, but sells for twice the price. It also gives good grazing for sheep in the winter

My second visit of the day was to the NSW Department of Primary Industries to meet one of their soil scientists, Warwick Badgery (great name!). He too is not a great believer in Pasture Cropping, and has done quite a lot of research into it. I should also mention that both Warwick and Angus do not know of anyone else who has managed to make Pasture Cropping work as well as it does with Colin Seis. Warwick puts this down to the unusual soil Colin has, which is very drought prone, and also very low in nutrients.

[It was plain to see when I visited Colin that the ground was made up almost entirely of granite, not dissimilar to some wine growing regions I have seen. The results of his soil tests did also show very low levels of total P, of around 850kg/ha.]

Warwick does not rubbish the idea of Pasture Cropping completely, he thinks it is a good technique to be able to use opportunistically when conditions are favourable and a cash crop looks like it may be profitable. This whole situation really shows up the fine line between the “it won’t work on my farm” conservative mentality, and the reality that conditions are different on each piece of land. It’s a tricky one.

Warwick has done a lot of work into farmland carbon sequestration rates, and how to maximise them. Apparently in Australia 70% of the nitrogen used by cash crops comes from SOM (Soil Organic Matter) mineralisation. This means that the organic matter is effectively burnt; the carbon leaves as CO2, and the nitrogen (and other nutrients) are left behind to be used by the crop. Obviously this is not sustainable in the long term unless there are recovery periods being used – which is where mixed farming comes in to play. A lot of farms over here incorporate grazing pastures into their cropping land, and this is how they can get away with it.

In Australian conditions, the absolute maximum amount of carbon that can be sequestered is 1t/ha/yr, which works out as roughly 0.3% of SOM. To get this figure a field must be a perennial pasture, and it must have high levels of inputs (nitrogen and phosphorus particularly). Interestingly, he claims that although it is possible to capture carbon without the inputs, it will remain in an unstable form that is easily lost again. On a similar note, I’m told that there are indeed bacteria that will fix phosphorus from the soil, but they only work when the levels are so low already that it would not be possible to grow a profitable crop.

Grazing system trials in Orange NSW

Grazing system trials in Orange NSW

One of the trials that is just finishing now is comparing different grazing methods, and different stocking densities. There are treatments ranging from low intensity set stocking, through to high intensity, long rest systems. The longest rests are around 120 days, which Warwick used to check the claims that this would allow better nutrients cycling and availability. He thinks they are wrong; 120 days appears to be too long for this climate, which is much more temperate than that at any of the other farms I have been to in the last few days.

One of the trials had severe over grazing last year, it was set stocked at a high animal density. The big surprise is that for some reason this year it has come back with incredible productivity, much higher than most of the other treatments. It looks as if either better nutrient cycling (through the sheep numbers), or a plant response to being grazed so heavily, has kicked them into overdrive. Not so surprisingly, the results are showing that with longer rests and higher stocking rates, feed quality and animal performance goes down. This is mitigated though by more efficient plant growth, so more animals can be farmed on a given area. Swings and roundabouts? But more animals and more plant matter must also mean more carbon going into the soil?

There’s no point living in an echo chamber and only speaking to people who agree with everything you already think. I think today was an good one, and although I didn’t hear what I “wanted” to, it has to be better to get the full picture. Even if it does make things more complicated. Excellent.

Day 44

Screen Shot 2014-11-10 at 11.20.40When I was in Canberra for the Nuffield CSC in March, there was a drinks reception where I met someone who was the head of agriculture, or something similar, at one of the big universities. I asked him what he thought of Pasture Cropping and the answer was “it’s rubbish, it doesn’t work”. This was a signal to me that there was probably something interesting going on, and I resolved to find out some more about it.

Colin Seis is a 4th generation farmer who produces Merino wool, and also a bit of grain. Like a lot of other farmers that have come up with very novel ideas, it all started with some extreme hardship. In the ’70s the farm had been going well, but in 1979 there was a severe bush fire which burnt all the pasture, all the crops, all the buildings, and killed 3000 sheep. With almost everything lost, it was time for desperate measures as there was not enough money to just continue on with the high input system that had been standard up until then.

A field of oats ready to harvest

A field of oats ready to harvest

What came out of it eventually evolved into Pasture Cropping. In the traditional system, pastures were established, grazed for 3 years, then ploughed up and drilled with a cereal. The problem is fairly obvious – getting a pasture going is expensive and quite time consuming, so it seems a waste to kill it off after such a short period of time. The answer is to not kill it off at all, but to drill straight in, and then let it regrow after the cereal is harvested.

But the key to making this possible is the climate. Australia is pretty hot, it’s been 35C today. In the winter it cools down quite a bit, and critically, the difference between summer and winter just crosses over the boundary that separates cool season and warm season plant growing conditions.

Native warm season grass seeds which Colin sells to coal mines for restoring rangeland after they have finished with it

Native warm season grass seeds which Colin sells to coal mines for restoring rangeland after they have finished with it

[Brief science lesson: warm season (C4) plants use a different chemical process for converting CO2 from the atomosphere to cool season (C3) plants. The crossover point between the two types is about 27C, and although being out of the right zone will not kill a plant, it will not be able to photosynthesise efficiently]

In this region there are 2-300 native pasture plant species, of which only 10 or so are cool season. This means that during the winter, almost all of the pastures’ productivity stops as the warm season plants become dormant. This is the perfect time to plant a cool season cereal, such as oats or wheat, as there will be no competition from the perennials that are already there.

One quarter of the farm is cropped every year, and to prepare a field to go into oats it will be grazed harder than usual, perhaps three times in the autumn (normally paddocks have 120 days rest between grazings on average). The oats can then be direct drilled in May, grazed a couple of times in the spring, and harvested in November. Yields are comparable to a conventional system, and immediately after harvest there is a fully established warm season pasture ready to go. I didn’t see it this time, as the drought it so severe, but normally at harvest the underlying grasses will already be greening up and starting to come out of hibernation. Of course, this can cause problems in a warm spring if they grow too big and interfere with combining. But that is apparently a rare occurrence.

Because it is so dry the warm season grasses are still lying dormant in the bottom of the oats. they look dead, but apparently are not...

Because it is so dry the warm season grasses are still lying dormant in the bottom of the oats. they look dead, but I’m assured they are not…

I was surprised to see that Colin uses a tine drill, I had assumed it would be impossible without a disc because of the amount of plant residue he was drilling in to. He can get away with it because the perennial plants have much better rooting than annuals and so they are much less likely to be pulled out of the ground and bung up the drill. He also mitigates the problem by using wide rows (12″) and recently cutting discs were added in front of each tine.

Does it work? Colin’s brother farms next door, and still uses the system he grew up with, so there is a great benchmark over the fence line. When two 50cm deep samples were taken from 15m apart, the difference was amazing. There is roughly double the nutrient density on Colin’s land, and double the SOM. Amazingly, over a 10 year period, the levels of plant nutrients in the soil have actually increased under pasture cropping, with almost no inputs at all. And that is not just plant available nutrients, but total nutrients. So somehow, from somewhere, phosphorus and all the other trace elements are being brought into the soil. To my mind it can only be coming up from deeper down in the soil profile, which is allowed to happen because of the deeper rooting plants which are encouraged with the cell grazing. It’s an incredible result, and unsurprisingly, a lot of scientists are skeptical about it. Nitrogen is also increasing, which is interesting because there are not very many legumes in the pastures. Colin is convinced that this is due to free living nitrogen fixing bacteria in the soil, which if true, is a real incentive to maximise soil health/life/whatever you call it.

But these are just theoretical numbers, practical results are more important: Colin’s land will hold over double the stock density of his brother’s, and yield the same with grain, but with fewer inputs. Why doesn’t his brother follow suit then? “He’s my older brother, and older brothers will never listen to younger brothers”. It also brings back something Gabe Brown says, “I get visited by farmers from all over the world, but I’ve never had one of my neighbours come and see me”.

Colin's tine drill, with a few modifications

Colin’s tine drill, with a few modifications

The latest iteration of Pasture Cropping is to stop growing monoculture cash crops, and instead plant a more diverse mix earlier in the year. Oats are still the base, but legumes like peas and vetches are added, and also brassicas which provide excellent forage for the sheep. These mixes are sown in March, and are then grazed 3 times. On the last grazing, the animals are left on a bit longer, which kills off the legumes and brassicas, but leaves the oats to grow though and be harvested later. The sheep are effectively acting as a herbicide. Colin is pretty excited about this development, as it allows legumes to come into the rotation, and it also gives another boost to plant and root diversity.

There is an elephant in the room: Pasture Cropping will not work in the UK.

However, this was an excellent visit, and very inspiring. It’s a system that goes completely against convention, and steps on some toes in the process. It’s very logical (to my mind anyway) when you think about it, and it begs the question – what is our equivalent going to be at home?