Using satellite imagery and analysis to maximise his seasonal fodder, Brad Wooldridge is doubling his pasture productivity and boosting wool cut by 60 per cent.
Data from current pasture performance is overlaid with climate forecasts, and compared to previous seasons of similar ilk.
Mr Wooldridge can predict feed on offer up to six months in advance, boosting stock management.
He runs a mixed farm operation, split between cropping and sheep, across two properties.
At Arthur River, in Western Australia’s southern wheatbelt, 300 hectares is devoted to pasture and 200ha to crop on “Warialda”. At Albany, 200 kilometres south, he has 230ha of pasture near the coast.
In 1999, Mr Wooldridge took part in a trial of CSIRO technology with 30 other farmers, which has developed into as a subscription service offered in collaboration through the University of New England and the WA government.
Pastures From Space (PFS) draws on Landsat satellite-derived Normalised Difference Vegetation Index (NDVI) to determine feed on offer, model pasture growth rates and total dry matter production. NDVI was developed to provide an index of how much vegetation is present at a particular point on the map.
PFS uses local climate, soil and evaporation data to generate a kilogram a day growth rate, allowing producers to asses their position, forecast conditions and to adjust their stocking rate accordingly.
At the end of the season, total dry matter is used to benchmark productivity, feed conversion and to predict seasonal outcomes.
Mr Wooldridge said the system’s key strength was its ability to depict the variability of productivity, and to predict future conditions.
“We use the PFS information to predict total dry matter for a season up to six months in advance.”
“PFS takes the emotion out of the decision making, so instead of just looking at the weather and hoping it will be alright, you can look at the graphs and say this season looks the same as the analogue seasons; and this is what happened in those years,” he said.
Pasture productivity per millimetre of rainfall has doubled during the past 16 seasons. Pasture growth has risen from 14kg/mm of rain to 28kg/mm while inputs have remained the same. In the same time, the wool cut rose by 60pc, while the number of Merinos and lambs a hectare has grown from four to eight.
This year, cropping is expected to comprise 40pc of his farm enterprise, compared to 60pc the previous year.
He currently runs 2100 mature ewes and 650 mated ewe lambs. Last year, his lambs averaged more than $80 a head, at eight lambs a winter grazed hectare.
His lambs are spring feed dependent and turned off at 100 days, targeted at the strongest market for weight, with an eye to feed on offer.
“We run six way composite sheep with a wool cut of 3.5 kilogram a head at 26 micron. They’re a very productive animal which we like for their wool, meat and temperament,” he said.
His sheep are one-sixth Merino currently, “that is only due to starting with Merinos, but each year it gets a lot less.”
“This year ewe lambs have almost no Merino in them.”
He said growth rate was important, which was why he liked the mating ewe lambs’ productivity.
“They convert feed to product very well and have the capacity to grow a lot of kilogram lamb per ewe.”
In wool production, he aims for 25 micron and a 3.5 kg cut in breeding replacement ewe types.
“Those with downs-type wool are mated to terminals with some Texel / Suffolk. We’re moving to shearing every six months, as some sheep grow very long staple lengths,” he said.
Mr Wooldridge consulted statewide vegetation maps before buying counter-cyclical grazing property at Albany.
“We average 420mm rainfall in Arthur River, but it ranges between 200mm and 500mm. You can't run a lot of sheep on 200mm, and we’ve had five of these seasons out of the past 15 years and we’re hoping that 2017 does not add to the tally,” he said.
“When it’s dry, you have to have somewhere to move your sheep, so we looked at the whole state greenness map for each month of the year and worked out where the grass was growing when it wasn't growing at home.”
For pastures, he uses sub clover, ryegrass and capeweed with a Kikuyu base.
He lets the capeweed grow in early winter, when the sheep do not eat it, allowing it to bulk up in the paddock.
Mobs are rotated throughout winter and lambing after an initial deferment of pastures.
“We work on a grazing rotation that’s based on the stocking density,” he said.
“We graze a paddock for half a day, up to three days, depending on how big it is.”
“The mob is moved into the next paddock and we try to give the grazed paddock a spell of 20 days, so the pasture can recover.”
Ewes are trucked north from Albany at the end of the growing season, which comes much later than Arthur River.
“We put them on stubbles over summer, and give pastures a spell to lower the worm burdens on the coast.”
A common weak link among many graziers is that they wait too long to react to seasonal conditions, Mr Wooldridge said.
“People will wait until they can see there’s a problem to rectify it, and by then it is too late,” he said.
“Very few people adjust their management early enough to match the stocking rate through winter to match their predicted feed production for the season, or have no concept of seasonal potential variability.
Mr Wooldridge said it’s easier to make a decision with the numbers from PFS in front of you.
“You can hope that the rain forecast on an extended weather site will eventuate and that it will be okay.
“But when you have the numbers in front of you, it’s easier at that point in time to make a decision, and the season doesn’t paint you into a corner.”
Mr Wooldridge said farmers can sometimes lack good understanding of how animals interact with pasture.
People will wait until they can see there’s a problem to rectify it, and by then it is too late
“That means knowing spell periods, and why animals shouldn’t graze pasture for more than three days at a time, or how fouling of pasture decreases animal intake,” Mr Wooldridge said.
“You need to understand that when you graze a plant it uses its root reserve to regenerate leaf growth. The plant’s roots contract and the energy is used to grow new shoots.
“If you graze a plant down too far and for too long it won't have enough energy to grow another leaf, and then productivity really drops off.
“You want to get the stock in to eat the pasture in less than four days, before new shoots come, and then take them off. It makes a massive difference.”
This article is sponsored by Rabobank