The first year of the fertigation trial running at McInnes Brothers farm at Harrisville has finished with some interesting findings. These were presented and discussed at a fertigation field day held in January.
About the Trial
The trial was run under a centre pivot in the 2017 autumn/winter months, under Aston ryegrass. One half of the centre pivot area was used for the trial, with one quarter (Q3) fertilised after grazing with Easy N liquid fertiliser, and the other quarter (Q4) fertilised with broadcast urea as a comparison. An Ecodose fertigation pump was purchased, at a cost of $2,900 (excl. GST) and installed at the pivot site, and the Easy N liquid fertiliser was purchased in 1,000L shuttles for this trial. Soil moisture monitoring equipment was installed with an Enviropro SDI 12 unit with tipping bucket installed in each quarter to monitor soil moisture content and in-crop rainfall for precision irrigation scheduling. Pasture dry matter yield was measured pre and post grazing using a C-Dax pasture meter to compare the two systems. Fertiliser and irrigation events were recorded.
Results from the Trial
Results of the on-farm trial demonstrated a production response in the pivot quarter that was fertigated compared to the quarter that was traditionally fertilised with broadcast granular urea*. The trial highlighted that even greater cost-benefits can be derived when the Easy N is purchased in bulk. For this trial, it was decided to purchase Easy N liquid fertiliser in 1,000 litre Intermediate Bulk Containers (IBC’s or ‘shuttles’) instead of going to the expense of bulk liquid storage in the early stages of the project. However, cost-benefit analysis has revealed that the cheaper price per litre of bulk Easy N will recover the extra cost of bulk storage set-up in the first ryegrass season, making it a wise investment choice.
Over the ryegrass season, bulk Easy N liquid fertiliser cost an extra 1 cent per kilogram dry matter utilised compared to granulated urea but yielded an extra 751 kg DM /ha. This translated to an extra fertiliser cost of $2,991.60 over the 18 hectare pivot area. However, when you consider that it would cost 35-47 cents per kilogram dry matter to purchase lucerne hay for the equivalent extra yield (i.e. $4,731 to $6,353), the extra cost of the liquid fertiliser is more than justified (see following table).
The fertigation system also resulted in a labour saving of approximately 18 hours (costed at approximately $500) over the ryegrass season. This takes into consideration that traditional broadcast application required getting a tractor, hooking on a spreader, filling the spreader and then 2 hours of tractor driving over the pivot area as opposed to merely pushing a button. Reduced tractor useage also derived further benefits of reduced fuel consumption, reduced repairs and maintenance, as well as reduced soil compaction and pasture damage. By spending less time on the tractor, human resources can be saved or directed towards alternate activities for even greater efficiencies such as improved grazing management.
The trial highlighted the importance of obtaining specialist advice prior to installing a fertigation system in order to maximise the benefits derived from improved nitrogen use efficiency. Precision is paramount and it is important that the irrigation system is operating at optimum water use efficiency. Initial setting up of dosing systems requires somewhat complex calculations but once established, the system is very easy to use.
The key benefits of fertigation were found to include:
• Reduced labour requirements
• Decreased R&M on machinery
• Fuel savings, less tractor work
• Could fertilise immediately following grazing, instead of days later
• Better timing of fertiliser, less volatilisation
• Reduced soil compaction with less traffic on pasture/crop
There are, however, some considerations to keep in mind before purchase of a fertigation system. These include an upfront setup cost (fertigation pump, bulk storage tank). The uniformity of application is only as good as the DU of the irrigation system, therefore it is vital to have a low pressure irrigation system with good DU. In times of extended wet weather, some fertiliser applications may be missed due to unnecessary irrigation applications. It may be still important to have a spreader for this reason, and to apply other nutrient requirements.
The trial will commence again in autumn this year for a second year, to try to improve upon some of the findings from year 1. Some grazing management changes will be implemented, in addition to an improved focus on irrigation scheduling and fertiliser applications.
Year 1 of the project was funded through the Australian Government’s National Landcare Programme, and was delivered by the Dairying Better ‘n Better program, a joint initiative of Queensland Dairyfarmers’ Organisation and Subtropical Dairy; and the Dairy and Fodder Water for Profit program.
* Please note an extra 54 kg N / ha was applied via fertigation compared to broadcast.
Fertigation and Irrigation Scheduling Factsheets
Contact: Ruth Chalk 0400 669 994 or firstname.lastname@example.org or Sarah Childs 0459 989 102 or email@example.com
Dairying Better 'n Better
In early 2001, the industry developed a Regional Action Plan for NRM (that has been revised and updated in 2006 and 2009) to provide a strategic basis for NRM in the Queensland dairy industry. This plan is endorsed by the Queensland Dairyfarmers’ Organisation (QDO), Subtropical Dairy Program (the regional research and development arm of the dairy industry) and Dairy Australia through the Dairying for Tomorrow initiative. Key research, extension, training, program development and implementation and advocacy priorities have been identified to address the priority objectives for NRM in the industry.
Through the implementation of this plan the Queensland Dairy NRM Program aims to reinforce the resilience of the Queensland dairy industry by assisting farmers to adapt to change and to be well prepared for the challenges ahead, whilst remaining profitable. To this end, the initialDairying Better n Better resource tools were developed as part of a large ‘whole of industry’ program between 1999 and 2002. The key outputs included the publication and distribution to all farmers in the subtropical dairy region of a best management practices checklist book and CD-ROM. Evaluation of this program revealed that awareness raising of environmental issues and promotion of available tools alone did not automatically lead to their use and therefore improved on-farm practice changes. Of the 160 participants in the program, 6% changed their practices as a result of the program.
Dairying Better n Better for Tomorrow:
In 2003, the Queensland Dairyfarmers’ Organisation (QDO) and the Subtropical Dairy Program recognised the need to combine resources to establish the Queensland Dairy NRM Program. The Program receives direction from the Queensland NRM Steering Committee which has representation from the Subtropical Dairy Program and Queensland Dairyfarmers’ Organisation. The Queensland Dairy NRM Program manages and implements the Dairying Better ‘n Better for Tomorrow Program and a suite of NRM projects, with the QDO managing the Queensland Dairy NRM team on behalf of the partnership.
Apart from the program partners, there are a number of organisations who support dairy farmers with natural resource management in Queensland. The Queensland Dairy NRM Program aims to integrate the activities of a number of partners, stakeholders, programs and plans to provide a coordinated and highly effective NRM support program for Queensland dairy farmers. Organisations that have been key partners in the delivery of the program in Queensland include:
- Queensland Department of Agriculture and Fisheries
- Queensland Farmers Federation
- Regional NRM groups
- Parmalat, Norco and Lion
The Dairying Better n Better for Tomorrow (DBnB) program builds on the Dairying Better n Better resource tools developed in 2002 and was refined following the implementation of the pilot project conducted by RuralScope Pty Ltd in 2003-2004 with support from Dairy Australia and the Subtropical Dairy Program. The program is designed to assist farmers to identify, develop and implement best practice natural resource management and environmental management practices on farm, to enhance the long term sustainability of the farm enterprise.The program adopts an industry managed approach, involving 8-15 producers in a sub-catchment working together with the support of a local facilitator and a Local Farmer Advocate (champion). Key aspects of the program include utilisation of the Dairy Self Assessment Tool (DairySAT); linkages with local, catchment and regional priorities; a workshop series to build skills and knowledge; action planning and implementation. The DBnB program provides farmers with an indication of the environmental performance of their operations, demonstrates that they have a plan in place to protect their environment, and are continually striving to improve it. The program assists farmers to assess their enterprise in terms of profitable sustainability and provide sustainable and profitable solutions to NRM issues. The program often is able to attract financial assistance for producers to assist them to adopt new practices on farm. Currently, 26 DBnB groups exist in Queensland, involving over 250 dairy farmers, which represents approximately 40% of the industry.
Dairying Better n Better On the Moo’ve:
DBnB also has a continuous improvement module, Dairying Better ‘n Better On the Moo’ve, which assists farmers to continually work at reassessing, prioritising and implementing improvements to NRM management practices on farm. This achieves the objectives of group sustainability, performance verification and continuous “action planning” that enables farmers to incorporate change into their farm management system. Dairying Better ‘n Better On the Moo’ve involves a formal review process of farmers’ NRM priorities by utilising a “scorecard” of their revised QDairySAT results. These group scorecards then serve as an anonymous vehicle with which industry can communicate its achievements.