Improved practices
Improved farm practices for profitability and sustainability
This case study has been made available on-line thanks to funding under the Australian Government's Eco-efficiency Agreement.
Following a recent industry tour, Tony Castro has a renewed enthusiasm and optimism for the future of the cane industry. The research work being done at CRC particularly impressed Tony with its possibilities for the industry.
"Tours like this one are invaluable to those who want to stay in the industry," says Tony. "Seeing the research and development work being done has given me a very positive outlook for the future of our industry, despite the major changes that need to be made. It is also important to look at what is going on in other rural industries because there are many ideas that we can modify to suit our industry."
Twelve or thirteen years ago drought conditions and reduced water allocations forced Tony and his father, Livio, into green cane trash blanketing. "Although we were forced into it, green cane has been the saviour of our business," says Tony.
In the first five years the Castros suffered yield losses but they persevered because they could see the potential benefits. About 35 percent of their farm required laser levelling to improve the drainage. It also took several years to change over to varieties suited to green cane.
After the first five years they started to see some real benefits with improved yields and better water efficiency.
Soil fertility
The Castros have drastically reduced the amount of cultivation they do to prepare for planting. Soil tests show an increase in organic carbon and improved nutrient levels. "The phosphorus levels are high and we are able to cut back on our phosphorus applications," says Tony. "There is also an increase in the number of earthworms present in the soil."
All ratoons are zero-till, except for the minimal disturbance caused by the scallop disc fertiliser applicator used to side-dress the stool. When a block is ploughed out Tony takes a soil sample in for analysis about two months before he wants to plant the next crop.
Recently Tony attended a nutrient management course as part of the COMPASS program. "I have always followed the recommendations given by BSES and the fertiliser company but I now have the added advantage of having a better understanding of the information on the analysis," says Tony. "This gives me added confidence when I make decisions about fertiliser products and rates."
Tony is also interested in trailing compost teas and other products from Nutritech Solutions. "I will do the trial using three blocks," says Tony, "on two blocks I will follow the recommendations of the fertiliser company and on the third block I will follow the recommendations of Nutritech."
Irrigation
Tony has implemented many of the practices developed by the Rural Water Use Efficiency program, such as irrigation scheduling. "In the past we tended to wait too long after rain before we started watering," says Tony. "We are finding that starting two or three days after moderate rainfall makes better use of both the rain and the irrigation water."
Tony has looked into using tensiometres to assist with irrigation scheduling but has decided he will install a mini evaporation pan instead. He believes the Enviro-scan type equipment is only cost effective where the farmer has the irrigation system that can deliver the optimal rates and frequency of irrigation.
To make the most of their irrigation dollar the Castros collect and recycle irrigation tailwater on all but one of their farms. "Water is so valuable now that the return on investment in infrastructure such as irrigation tailwater recycling is quite rapid," says Tony. "For instance, last year a tailwater pit on a 40 hectare farm filled three times during the year, giving us 15 ML of water that would otherwise have been lost."
Two seasons ago Tony changed from a ring nozzle to a tapered nozzle on his travelling irrigator. He has seen the improvement in crop uniformity across the blocks and there has been no change to the amount of water used. The more even distribution has a two-pronged benefit, firstly in better infiltration across the block and secondly in reduced runoff from the overlap section.
On one of the farms a previous owner had planted into very high mounds with v-shaped furrows. Tony found that using a much lower profile and flatter inter-row was better suited to the soil type, providing better water infiltration and so better yields.
Rotations
Tony and Livio have noticed the effects of long-term monoculture on their farms and no longer practice plough-out / replant. They have also decided to use soybean as the legume break crop on their farms. "We grow the soybean for grain believing that even if some of the fixed nitrogen leaves the farm as grain, we are still getting the benefit of a break from sugarcane," says Tony.
The long fallow, incorporating a summer legume crop, is giving rise to better yields. Tony believes in the benefits of minimal tillage to preserve as much of the organic carbon as possible. "Working the ground too much burns up the carbon that is needed to make the most of other nutrients in the soil," says Tony. "So we only work the ground once or twice, depending on whether we need to apply lime between harvesting the soybeans and planting the Spring-plant cane."
Row spacing and zero till
The Castros are also making the move to wider row spacing. This Spring they will trial moving from their current 1.5 metre row spacing to either 1.65 or 1.8 metres. "We will stay with single row, wide furrow planting but our main concern with widening the rows is whether we will be able to continue to flood irrigate successfully and efficiently in our soil type," says Tony. "We need to go a bit wider at least to reduce the amount of compaction of the stool under our current row width."
The home farm is irrigated using a travelling irrigator and Tony believes that the 1.8 metre rows should be efficient under this irrigation system.
Tony is convinced there should be benefits in controlled traffic and permanent beds so he intends to conduct an on-farm trial to make an assessment of the suitability of these systems on his grey forest loam soil. He plans to use two blocks to compare permanent beds against breaking up the beds and inter-row at the end of a crop cycle. "I think there is probably a place for permanent bed farming in the cane industry," says Tony, "but I will need to make my decision based on the performance of crops on my own farm."
"Seeing things trailed at a commercial scale is an important part of the development process," says Tony, "and it carries even more weight if you do your own trials."
Herbicides and pesticides
Tony is conscious of the need to be very careful with the types and rates of agricultural chemicals used on the farm. "There is no doubt that serious damage can be done with over use or misuse of chemicals," says Tony. "Moving away from cultivation generally means more herbicide use so it is important to fine tune application techniques."
Monitoring the water pH is one way that Tony is able to reduce the amount of chemical applied while maintaining maximum effect. In the next year or two Tony also intends to look at getting a hooded sprayer so he can use low rates of glyphosate products instead of residual chemicals for weed control.
Tony has moved away from chemical control of cane grub, finding that thorough cultivation of the fallow blocks using a square plough is doing a good job in controlling grub populations but not knocking out the beneficial soil organisms that build up under the trash blanket.
White fly is a major pest in the soybean crops. Tony monitors the presence of this pest and takes advice on when to spray from a local soybean agronomist. "It is a very delicate balance between suppressing the pest and wiping out all the other beneficial insects that help keep the pest under control," says Tony.
Tony sees a bright future for the industry as it becomes a more multifaceted industry and believes that other growers would be motivated if they took the opportunity to look into the research and development work being done in the industry.
