Irrigation is utilised by a range of land uses, in areas of Aotearoa New Zealand that have restricted rainfall, impacting production (i.e. pasture and/or crop growth). The main irrigation areas in Aotearoa New Zealand include the eastern parts of Hawkes Bay, Wairarapa, Marlborough, Canterbury, and Otago. About 65% of irrigation in Aotearoa New Zealand takes place in Canterbury.
Good management practices were developed in partnership by industry groups, crown research institutes and Environment Canterbury. These include:
Make sure there is a demonstrable reason why irrigation is to be applied:
Soil moisture monitoring is based on the soils Profile Available Water (PAW) and is generally shown through a soil moisture trace.
It is good management for irrigation decisions to be made through soil moisture monitoring, rainfall and weather forecast.
Source: ECan
Source: DairyNZ
As a manager or advisor for irrigation there is responsibilities to have strategies in place including:
Source: DairyNZ
Ensuring the irrigation system is efficient:
Variable rate irrigation (VRI), where the application rate of irrigation water across an area changes depending on soil type and other factors, can decrease leaching losses of nitrogen (N) and phosphorus (P).
At a farm scale
At a broader scale
Effluent is a combination of manure, urine and washdown water. Effluent is a valuable resource which, when managed well, increases pasture production and reduces fertiliser costs. There are generally two components to an effluent system; storage and application. By designing effective collection, storage, treatment and dispersal systems, we can use them to maximum effect - whether that's to increase pasture production, or protect the quality of our rivers, streams, oceans and groundwater.
The nutrients, and other contaminants within effluent can cause environmental damage, especially in fresh and ground water.
Good effluent management is a combination of having a well-designed effluent system and processes for people that make sure the effluent the system collects is applied to pasture in the right amount at the right time. Benefits include:
Source DairyNZ
Having well-designed and constructed storage facility will save you time and money. The key is good planning and working with the right people.
Storage ponds need to have the correct amount of cubic metres to ensure compliance and enable appropriate spreading, and be lined appropriately to stop leakages.
Storage options include lined ponds and above ground tanks are the two options available when choosing an effluent storage system for your farm.
DairyNZ has developed the Dairy Effluent Storage Calculator (DESC), with herd size, climate information, yard size and daily water usage can determine the required cubic metres. A Dairy Effluent Warrant of Fitness (EWOF) certified consultant is able to assist with this calculation.
Farm Dairy Effluent (FDE) systems should:
How you can do this with a Farm Dairy Effluent (FDE) system:
How you can do this with a deer enclosure system:
Spreading is important to ensure effluent is appropriately utilised, and does not contaminate surface or ground water.
The key to good effluent spreading 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.
Application of farm dairy effluent should be avoided on shallow, stony free-draining soils with low capacity to retain P. Soils of this type are common in the Canterbury region. Current regulations and good practice for dairy farms are not enough to mitigate phosphorus (P) losses from FDE applications on these soils.
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. OverseerFM can also assist with determining nutrient loading. 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.
Spreading sludges and separated solids
Effluent is commonly grouped into three broad categories based on dry matter (DM) content: liquids (0-5%), slurries (5-15%) and solids (>15%).
Spreading effluent solids requires specialist machinery which is suited to the type of effluent being spread:
Downloads
How you can do this:
How you can do this:
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.
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