Insuring specialty crops irrigated raised beds
GroundCover™ Issue: 28
Farming on raised beds at Griffith in the Murrumbidgee Irrigation Area (MIA) gives Terry McFarlane the flexibility to get the most out of every drop of water. "Water," he says, "is our most valuable resource, and every megalitre must be maximised."
Raised beds give him the confidence to contract specialty crops and to market them 12-15 months out. "With this system," he says, "I can explore new markets and new crop options, and I can winter-crop, summer-crop or double-crop."
A typical rotation would be squash for seed, canola, seed wheat followed by another crop of squash for seed. There's no pasture phase in the rotation and no stock in the equation.
There's no pre-sowing watering required with raised beds, a critical consideration. Mr McFarlane explains that he picks what he considers to be the optimal time to sow his crop, and simply works back from there.
"I decide when I'm going to sow. I sow dry and then the water goes on. If we get unexpected rain the system gets water off the paddocks fast. I could be back working again 10 days after a two-inch rainfall," he says. "If I'd pre-watered and had two inches of rain it could take me a month to get back on the paddock."
Controlled traffic, too
The raised beds on the McFarlane property are the standard 1.8 m wide and about 150 mm high. All machinery on the property is designed to work across three beds. Before forming the beds Mr McFarlane deep-ripped the country to open up any hard pans. Now there's no more wheel traffic across them, and no compaction.
After rainfall, water drains quickly out of the beds into the side furrows. Irrigation water from the side furrows just as quickly fills the profile of the beds.
Crops grown using the raised-bed system don't use any less water than crops grown under the traditional border check system, but they make better use of it. The bed's soil structure and its ability to absorb and hold moisture improve every year, boosting crop potential. Last year the wheat crops averaged 6.8 t/ha.
Typically the irrigation run is 750 m, about the maximum manageable with a 12-hour irrigation shift. Mr McFarlane has budgeted for two irrigations for the seed wheat crops he now has in the ground, but hopes to get by with just one. The water saved, along with any rainfall that drains off the paddocks, will go towards summer crops.
The farm had a developed reticulation system when Mr McFarlane bought it from his father. "Without reticulation I simply wouldn't have considered raised beds as an option," he says.
Arguing that it costs no more to establish a crop under the raised-bed system than using conventional farming techniques, Mr McFarlane nevertheless concedes that he didn't have to make an expensive machinery changeover. "I bought very little machinery with the farm and had a particular farming system in mind, so any machinery I bought fitted that system," he says.
The backbone is a single implement that cultivates, forms the beds and applies both solid and gaseous fertiliser. "It does just about everything but sow the crop and harvest it. It is the big-ticket item," says Mr McFarlane, "and cost around $30,000." Other machinery, including a modified sower and a mechanised hoe to work up the tilth of the beds, and the piles of syphons needed for the system, push the all-up machinery establishment costs to around $75,000.
Raised-bed farming for Mr McFarlane is about risk management. It gives him confidence in the farm's performance, "and if you're going to contract for specialty crops you have to commit yourself early". It also gives him the confidence to market as much as 80-85 per cent of crop potential 12-15 months in advance.
Contact: Mr Terry McFarlane 02 6963 6536
Region North, South, West