My assignment is still lurking around in the shadows of my Wednesday, so here we go, back into my developing field report.
So this morning we’re going to talk about grazing, specifically we’ll be talking about the merits of conventional versus organic versus time controlled grazing. I then have to decide which is the most sustainable, economically and environmentally, and then justify that decision.
Oxton Park, Buronga and Tulgani: Discuss the advantages and disadvantages of these various agricultural practices, and therefore which is the most sustainable (both environmentally and economically).
So grazing. Yeah.
We saw a conventional grazing system at Oxton Park. It’s an 8000 ha property with 200 ha set aside for grazing.
They had their soils classed and they have classes 1 – 5. Soil classing works like this; hazards are used to assess capability; the potential consequences of a hazard and the likelihood that that consequence will be realised. The LSC is based on the most limiting hazard. Soil classes go from 1-8. You can do anything you like with 1 but 8 is rubbish country. The assessment scheme is the major tool to assess the sustainability of land management practices. It follows on from one made for the Central West of NSW in 2008 (which was itself based on the US Dept of Ag scheme from the early 1950s). A Land and Soil Capability (LSC) assessment scheme is most suitable for broad scale assessment of land capability particularly for low intensity dry land agriculture-less so for high intensity use or irrigation.
So they graze on class 5. They crop for four years on classes 2 – 4 then graze for 15. This very long term thinking is in place as the farm is not a family farm but a business. They are playing with huge amounts of money and every paddock has a plan for it; they know what they will be doing there every year for about the next 20 years.
They run about 30 000 merino, mostly for superfine wool. 16 000 are pure merinos and 6000 are a quicker growing crossbreed that they use for meat, which is now worth more than wool. The meat sheep are exported if they’re more than 11 months old.
Wait, what’s superfine wool? How is it different to normal wool?
Good question Internet. Superfine wool is 18-19 microns thick, which is the diameter of the wool. Wool is also measured on it’s tensile strength, but the diameter is the most important factor and is dependant on the sheep’s age, breed, health and so on. Merinos are known for their superfine wool, which is used in thermal and luxury products.
They shear every ten months, generally in April and January. You need about 70mm of wool to make it worthwhile and you shouldn’t shear them in winter (really?!) or when they’re lambing.
This way of raising sheep is very high input, both in terms of money and time. You have to drench them and crutch them; you have to shear them, you have to move them from one paddock to the next.
The advantage is that you get a consistently high quality product, but the disadvantages are that if you run out of money or inputs the system will collapse. Also, because they’re grazing their sheep on class 5 land, it is reasonable to expect that the sheep’s diet isn’t great as the pasture in those paddocks may not be very varied. If this system was hit by a serious drought the farm would probably be fine financially but it’s anyone’s guess how the land would go after being managed to produce meat and wool rather than to produce pasture with the sheep as by products.
So what’s your conclusion?
Well Internet, it’s probably only sustainable financially as long as you have enough money to put into it and aren’t hit by a big drought; it’s very dependant on inputs. Environmentally it’s probably not that resilient, although good on them for understanding their soils and utilising them correctly.
Tune in next time for the same again, but with organic grazing!