Vibratory roller, excavator, boost rocky country’s value

About 35 years ago, Fred Mulligan paid $45 an acre for Salway, 2100ha (5200 acres) in four paddocks, covered with blackberries and untrafficable even in a four wheel drive because of rocks.. Son Robert claimed they even had a huge stud blackberry bush that covered about 30ha. To destroy this massive infestation, they launched a spraying program. As well they bought a Komatsu D65 dozer and a Komatsu D75 track loader for other land improvement and development work.
About 3 years ago Fred and Robert decided that with all the clearing and other farm development done, it was time to address the rock issue.
In some areas surface rock has been so prevalent they had difficulty moving animals to gateways. Also, many areas were inaccessible due to large rocks and high grass, especially in spring and summer. Vehicles too, and particularly quad bikes, were continually being damaged and people put at risk as they accessed rocky areas through long grass studded with protruding, wet and slippery, basalt rock.
Excessive track wear
Their first effort was to hook an 18t roller to the D65 dozer. While this worked, the punishment to the walking gear on the dozer was extreme, as the tractor had to walk across the protruding rock before the roller flattened and pressed it into the earth. They also tried a contractor with a big wheel tractor. However it had the same problem as the dozer: excessive tyre wear.
Father and son decided a new path was needed and they bought two brand new machines that they felt would do the job they required. The first was an 18t Caterpillar CS-683E vibrating roller. The second was a 20t Hyundai 210 LC-7 excavator, fitted with a tilt bucket, logging grab and rock rake.
If the ground is lightly covered with scattered rock the roller goes in alone and rolls the rock into the earth. Where there is excessive rock, they use the excavator to pull the rock apart and windrow it.
The excavator then loads the piled rock onto an S line International bogey tipper, which takes it to other parts of the farm, to be used in creek crossings and farm roads. As soon as the site is cleared the roller comes in and rolls any remaining protruding rock into the ground.
Soil moisture vital
The first consideration for job effectiveness is soil moisture. It was high the day I was there and the roller was pushing most of the rock directly into the ground. It was breaking about 30% with this breakage varying from two or three cracks to blue metal in some instances. The big roller certainly shook the ground as it could be felt underfoot 20 or so metres away from the working machine. There was little doubt as to the value of the vibrating action, as it really broke the rock, where a static roller would not have been as effective
The operation is not cheap with costs of around $500 a ha ($200 dollars an acre). However, just to sow high yielding pasture can cost in the vicinity of $370 a ha ($150 an acre).
The Mulligans expect this treatment to last a long time before rocks appear again. The only time they have done a re-roll so far is where rocks have reappeared in paddocks where hay or silage is to be made.
Robert explains that they are already running more animals and running them better. They are still developing the farm being about halfway through a 20-year rock minimisation program. Currently they are permanently running a 1200 head cow herd. As well they buy and fatten about 8000 lambs a year.
Hay, silage possible
The area of the farm that has been treated is now available for making hay and silage, an operation that would have been totally out of the question, before the rock management program started.
This has resulted in extensive silage conservation never before considered. And the Hyundai excavator has been most useful in the silage operation.
I used dozers to excavate silage bunkers all over New England for many years. But I was impressed with the bunkers the Mulligans had built with their excavator on the sides of hills. That is because they are quicker to make and put the earth on the side of hole and not scattered down the hill. Later it could be placed easily over the top of the bunker once it was full Also they use it to easily extract the silage for feeding out.
Vehicle and quad bike access to the treated areas is now virtually unlimited with such things as tyre wear greatly reduced too. Before the rock program, tractor tyre life used to be as little as 400 or 500 hours; now it is close to 10 times that. Also, Fred told me that the farm repair bill for 4WDs, quad bikes, tractors and associated machinery, had all dramatically fallen thanks to rock removal.
The most exciting part of all of this is when we look at land values. By spending about $500 a ha, the Mulligans have turned much less productive land into country worth in the vicinity of $7500 a ha ($3000 an acre). Their agronomist too is very interested in what impact mineral releases from the broken rock will have on soil fertility. Also, cracked rock makes more gateways for water to infiltrate the surrounding area.
This has to be the sort of project and business decision that makes a bank manager truly salivate. Why would you buy the place next door, when your own is like this country and can be so successfully improved?