On-farm benefits of good effluent management include:
- Fertiliser savings
- Improved soil condition
- Prevention of animal-health issues
- Compliance with council rules or resource consent.
Making good effluent irrigation decisions
The key to good decision making is understanding the soil water deficit. It is essential to prevent ponding and run-off and to avoid applying effluent to saturated soils.
Soil water deficit is the amount of water (ie effluent) which can be applied to the soil before it reaches field capacity (which refers to the amount of water held in the soil after excess water has drained away). If effluent is added at field capacity it will likely result in ponding, runoff or leaching.
The average dairy cow produces about $25 worth of nutrients annually as farm dairy effluent (FDE). For a 400 cow dairy herd this represents about $10,000 of nutrients annually. If these FDE nutrients are used effectively then this significantly reduces the fertiliser bill. For more information see the Nutrient value of effluent Farmfact.
Effluent spreading calculator
The DairyNZ Farm Dairy Effluent Spreading Calculator (app or Excel spreadsheet) allows farmers to easily calculate nutrient loadings and application rates for dairy effluent based on a number of customisable inputs. This means that farmers can manage the application of their effluent nutrients with greater precision.
There are two calculators in this app, the Quick Calculator which is for spray irrigation systems such as travelling irrigators and sprinklers, and an Advanced Calculator which is for slurry tankers and muck spreaders. It is also available as an excel spreadsheet if you prefer to use your computer.
Download this handy app to take the guesswork out of determining your effluent nutrient loadings
Spreading sludges and separated solids
Spreading effluent solids requires specialist machinery which is suited to the type of effluent being spread. For information about effluent solids spreading methods, considerations and equipment see Effluent Slurries, Sludge and Solids Spreading.
When using a contractor to spread the effluent (solids or liquids) the Compliance Toolkit has a form to help reduce communication breakdown between farmers and effluent spreading contractors: Effluent spreading contractors' communication form.
Irrigation application systems
Keeping on top of maintenance tasks for irrigation application equipment is essential for good performance and many farmers like to keep a regular check on their application depths and rates.
The guides below will take farm staff through the important parts of operating and maintaining irrigation systems. They include tips, trouble-shooting advice, and an explanation of how to measure application depth and rates.
If using a centre pivot see our Guide to Good irrigation Part 1 - Irrigation practices on Farm.
This effluent tool has been developed with the help of farmers all around New Zealand. It provides the top tips for effluent irrigators.
This effluent tool is designed to take some of the headache out of training staff and managing your effluent system.
This effluent tool has been developed with the help of farmers all around New Zealand. It is designed to take some of the headache out of training staff and managing your effluent system.