The science of soil management and crop production, or ‘agronomics’ is a complex and constantly developing field. Best practice in agronomics can ensure optimal yields, while maintaining soil health and ensuring the viability of agricultural land into the future. Here, we take a look at some of the latest research into agronomic practices in sugarcane farming, and their implications for farmers in Australia.
Choosing the right varieties
New varieties of crops are regularly being developed, in order to better suit diverse seasonal and soil conditions around the world. Sugarcane varieties are updated frequently by breeding institutes, universities and research & development centres such as Sugar Research Australia (SRA). SRA’s 2016-17 guide to sugarcane varieties can help farmers to choose the best crop for their conditions, and assist with directions on when to harvest and how to do so.
Needless to say, choosing varieties which are resistant to the diseases encountered by each region can make the world of difference to the yield of each crop, and can affect future crops for several seasons. It is important to take note of the estimated yield of each variety, versus its resistance to the relevant diseases. SRA also provides recommendations for crop varieties based on soil type, which are to be used alongside a soil type map available from local productivity services groups (p. 7).
SRA conducted a 4-year trial with a number of farmers which looked into the application of nitrogen to sugarcane crops. During the RP20 Burdekin Nitrogen Trials, farmers used the ‘six easy steps’ method to determine the necessary nitrogen fertilisation for their crops, and the results were surprising for many. According to the Sugar Research Australia ‘Best-practice nutrient management’ information sheet:
“Modification of the traditional nutrient-management guidelines for sugarcane production in Australia has been in progress for the past 10 years. The need for change occurred with a realisation that nutrient management should no longer only target sugarcane yields, but should be aimed at sustainability. Increased study and research has led to a better understanding of soil types and appropriate nutrient application rates.”
The ‘six easy steps’ method involves:
- Knowing and understanding your soils
- Understanding and managing nutrient process and losses
- Regular soil testing
- Adopting soil-specific nutrient management guidelines
- Checking on the adequacy of nutrient inputs (eg leaf analyses)
- Keeping good records to modify nutrient inputs when and where necessary
One of the RP20 trial participants, sugarcane grower Eric Barbagallo is pleased with the results on his farm. Over four years, he and his fellow participants have managed to debunk the long-held myth that more nitrogen equates to higher yields. As he and other farmers in the trial reported, many were reluctant to reduce their usage, as they imagined their yields would suffer.
Mr Barbagallo told SRA:
“It’s not until I got involved in RP20 that [I] learnt that you don’t need to waste that amount of fertiliser to grow cane.”
He reports that their yield has stayed fairly consistent, their CCS has risen slightly, but they are saving money on fertilisers by now applying less.
“[It’s] more money in our pocket every year. It’s a given, if you put less fertiliser on and your results don’t change, that’s one less expense really,” he says.
Another farmer reports having saved at least $100,000 in fertiliser over the period of the trial. Through improving irrigation, reducing their nitrogen application, and looking at an overall farm management plan, these kinds of savings are just the beginning.
Sustainability is a key concern of the trial, and of soil management practices being trialled by SRA. This, and other trials like it result not only in savings and increased yields (through better overall practices), but water quality improves thanks to fewer fertilisers being used.
Adequate amounts of nutrients and water are, of course, critical to any crop growth. Being such a large crop with an extended growing period, sugarcane requires substantial irrigation and fertilisation. Delivering these effectively and efficiently to the crop can result in huge savings for farmers. The costs associated with fertilisation, pest management and irrigation are substantial and potential savings in these areas represent a direct impact on the back pocket.
Fertigation allows both water and fertilisers to be delivered directly to the where it is most needed. According to Netafirm:
“Fertigation Offers Several Distinct Advantages in Comparison to Conventional Application Methods.”
These advantages include:
- More even distribution of nutrients, resulting in increased uptake and better yields
- Targeted delivery of nutrients depending on crop development phases
- Minimal loss of nutrients to weeds, leeching and runoff
- No breakage of leaves or damage to crop by application of fertilisers
- Less labour-intensive systems
- Lower spend as a result of targeted application and less wastage
According to Netafirm’s agricultural department:
“In sugarcane weeds have been estimated to cause 12 to 72 % reduction in cane yield depending upon the severity of infestation.”
Due to the relatively wide row spacing and slow initial growth of sugarcane, it is more susceptible to weed infestation than many other crop varieties. Crops compete with weeds for access to sunlight and water, as well as nutrients. Proper weed management is therefore critical to crop yield, soil health and sustainability. SRA have released a tool for Australian farmers to tackle weed problems in sugarcane. The Weed Management in Sugarcane manual was written by SRA adoption officer Phil Ross and SRA weed agronomist Emilie Fillols.
“Yield losses from weeds, along with the costs of weed control, is estimated to cost the Australian industry $70 million each year,” Mr Ross said. “This manual is targeted at the dual aims of helping growers to combat weeds, and also ensuring that every dollar spent on weed control is efficient.”
The manual hopes to assist farmers in managing their weeds effectively (by identifying weeds correctly, and applying solutions which target these appropriately), but also ensuring efficiency in weed management spending. Much like fertilisation, weed management in an area in which farmers are likely to overspend due to a lack of understanding and readily-available, successfully-trialled research. Beyond increasing yields and decreasing spend on weed management, the practices outlined in the manual also have positive effects on the environment through reduced (and more targeted) use of herbicides.
Farmers can request a copy of the manual from SRA by contacting Ms Andrea Evers on firstname.lastname@example.org or (07) 3331 3308.