Farm management
Farm Management helps Plane Creek growers change and stay ahead
By Cindy Benjamin
Brian and Margaret Stevens have a program of continual change on their 355 hectare farm at Ilbilbie, in the Plane Creek Mill area. Brian's parents started farming in the area in the late 1940s and while in partnership with his parents, Brian saw the move to green cane as the first step in a long conversion process.
"Over the last 17 or 18 years we have seen a huge amount of change," says Brian. "I believe that the change to green cane harvesting has had the most significant effect and is the main reason why we have been able to survive this current drought."
The change process
The change to green cane harvesting had a big effect on water retention, irrigation efficiency, and stopped soil erosion from ratoon blocks. The Stevens' were also able to cut their herbicide use from two kilograms of Diurex and two kilograms of Atridex per hectare down to just 1.5 kilograms of Diurex per hectare for pre and post emergent weed control.
Off-farm movement of soil at planting was still a problem so the Stevens' reduced their cultivation by half in their plant cane. The next step was to widen their row spacing and again reduce the area cultivated by only cultivating the planting zone. Controlled traffic on 1.85 metre drills has reduced cultivation time by one half and Brian is keen to go further down the reduced tillage track. Brian has opted for dual row planting with the two rows 500 mm apart.
This year Brian has 60 percent of the farm converted to the controlled traffic, reduced tillage, rotation crop farming system, a process that has taken about five years so far. Brian's intention is to plant into the cane and soybean trash with minimal disturbance. "The trash has the most benefit when it is on the soil surface, providing mulch to suppress weeds, conserve moisture and eliminate splash impact from rain and irrigation," says Brian.
The Stevens' will maintain permanent beds unless the beds are damaged during a wet harvest. They will not cultivate the interspace between crops but will maintain the tracks and restrict land preparation to the bed area.
Brian is interested in the results of variety testing under dual row conditions. He currently has Q135, Q138, Q157, Q185, Q209, Q205, Q207 and Q208 planted on the farm, all of which were selected based on their performance under single row conditions. Brian is not sure whether there is much difference in variety performance under the two systems but will take it into account when selecting varieties in the future.
Brain sees a strong similarity between the change process involved with green cane harvesting and the current move to controlled traffic and wider rows. "For most people the first step was to reduced tillage in burnt cane, then green cane farming was shown to reduce chemical usage and conserve moisture," says Brian. "The final step that made conversion a reality for many was the introduction of the series 7000 harvesters."
"The same process is occurring now where the benefits of controlled traffic, wider rows and rotations are being demonstrated and slowly the technology is all starting to fit together, making conversion easier," he says.
Fertiliser management
Over the last three years the Stevens' have grown soybeans to help reduce their reliance on nitrogen fertiliser. BSES nitrate and pH tests following the soybean crops have shown that no added nitrogen was necessary for the plant cane crops. Using soybean as a break crop has led to a 15 percent reduction in total nitrogen required for a crop cycle.
"We will consider harvesting the soybeans once we have got the growing side right," says Brian. "The added expense, increased insect management and potential wet harvest problems make it a low priority. If we just grow for green manure we can better manage soil moisture and we get good value for money from the nitrogen inputs from the crop."
Targetting yields
Liquid one-shot, a premix of dunder, nitrogen and phosphorus, is manufactured at the CSR distillery and is a popular fertiliser in the Plane Creek area. The liquid one-shot is applied on the soil surface and watered in.
Over the last few years the Stevens' have applied fertiliser to their ratoon crops according to a pre-determined target. "Each year we look at the past history, age of the ratoon and the amount of water available for each block," says Brian. "We then decide what our target yield will be for each block and apply fertiliser aimed at achieving that yield."
"We consider the amount of available irrigation water and the long-range rainfall forecasts," says Brian. "The drought we have experienced over the last four or five years has prevented us from reaching our targets by about 10%."
As a result of their target yield strategy the Stevens have reduced their nitrogen fertiliser rate from 195 kilograms of nitrogen per hectare across all ratoons to an average rate of 140 kilograms of nitrogen per hectare. They use a computer spreadsheet to track how well they match the fertiliser rate to the target yield for each block.
Changing planting time
Brian knows that some people are avoiding growing soybean because they are concerned about the soil drying out under the soybean crop but this has not been a problem for the Stevens'. "We have found we are able to plant around July - August," says Brian. "We intend to keep moving forward until all our planting is done in April or May."
Although early planting has been associated with heavy rain and waterlogging, Brian believes that by planting into raised beds, waterlogging will be reduced. By maintaining good surface cover on the beds the risk of erosion will also be minimal.
Machinery modification
There have been a few necessary changes to machinery including disc openers being added to an existing fertiliser bin frame and a replacement planter that can plant dual and single row configurations. Dual row planters are becoming more common amongst contractors and grower groups.
One of the harvesters in the co-op that the Stevens belong to has been changed to a BSES front, with wider spirals, better suited to dual row cane. They are also involved in a study of elevator extensions to look at the best way to modify elevators to suit both single and dual row farming.
The Stevens' are also installing GPS guidance systems in one of their tractors. "We want to install one in the harvesters too," says Brian. "With night harvesting and controlled traffic you really need the GPS technology."
Harvesting efficiency
Until this year Brian has cut his own cane, in partnership with one other grower. This year he and his partner have joined a harvesting co-op in which three harvesters will operate two shifts and cut over 240 000 tonnes.
Brian's involvement with the harvesting side of the business has made him aware of the need to set up his farm with efficient harvesting in mind. The Stevens have had an ongoing lazer levelling program over the last ten years or so and now most of their farming land just needs a trim at the end of a crop cycle to keep it right. They are also looking at ways to increase row length to improve harvesting efficiency, such as harvesting across headlands wherever possible. The average row length is around 500 metres across the farm.
Irrigation
The Stevens' have the capacity to store 600 ML of water on-farm. "We water harvest from the creek and can flood irrigate 170 hectares," says Brian. "Only one farm is suited to flooding and we have a tailwater dam on this farm to collect and recycle any runoff."
The Stevens also have one dryland farm and winch irrigate two other farms from a couple of bores with a small supply of water. They maximise the productivity of the land with irrigation available and harvest the dryland farms when the soil moisture is sufficient to get the ratoon crop to strike.
Economic studies
The Stevens' are assessing the economics of fourth and older ratoons. Their current practice is to grow four ratoons but Brian believes that there may be benefits in reducing the crop cycle length. "In the later ratoons we notice a significant drop off in yield, especially in dry years," say Brian. "But this has to be weighed against increased frequency of planting and the extra cost of having a larger area planted each year."
Over the last three years the Stevens' have seen a four percent increase in yield that they can attribute to their new farming system. "I think that yields will be depressed in dry years regardless of your farming system," says Brian. "We expect to see real improvements under good growing conditions."
