Irrigation Evaluations (aka Bucket Testing) - Including tips for testing VRI systems

Spring is here but we are seeing all four seasons rolled into one some weeks which is not an anomaly. The soil moisture levels in our region have had a healthy boost in the last few days but if the media reports are true we may be in for a dry summer - please don't shoot the messenger, I'm only relaying what I have heard.

Should this transpire then that is even more reason to ensure that our irrigation systems are applying water as efficiently as possible so that we are maximising the amount of water applied that is available for plants to grow. An irrigation evaluation is a way to assess the efficiency and distribution uniformity of your irrigation system to ensure it is performing as expected.

An irrigation evaluation will help identify causes of any poor performance and (sometimes with the assistance of a qualified professional) show how these can be resolved. Increasing irrigation effectiveness and efficiency will allow you to grow more for less.

An irrigation evaluation (often referred to as a bucket test) is simple enough to carry out yourself, there are several good guides freely available to walk you through this process. For more information check out:

IrrigationNZ - Bucket Testing Resources
DairyNZ - Irrigation Evaluation Guide

The guides recommended above will walk you through how to carry out a standard bucket test however before you begin you need to consider any additional technologies that enhance your irrigation system. For instance if your system has variable rate irrigation (VRI) technology then you will need to take this into account when planning your bucket test. Lindsay NZ, the developers of the Growsmart Precision VRI system, have created a step-by-step guide that explain these additional considerations in more detail.

Growsmart Precision VRI - Bucket Testing Tip Card

If you are not in favour of the DIY irrigation evaluation option then consider contacting an accredited evaluator, this would also be recommended if your own test identifies potential issues that warrant further investigation. If you have additional technology such as a VRI system then ensure that whoever is carrying out the test is aware of this and that they carry out the recommended additional steps. If you need further help then contact your irrigation dealer, many dealers also have accredited evaluators on hand.

Irrigation system checks and maintenance should be undertaken at scheduled times over the irrigation season (the more hours your irrigator runs for the more regularly these checks should be carried out). Recommended irrigation system maintenance will be covered in more detail in the next H2Grow blog post, this will include a checklist that you can download and print off to help you with this task.

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Today's blog was written by Sarah Elliot from Lindsay NZ - I hope you have found it useful!

Regulatory Update

Below is a quick update on where things have gotten too from a regulatory perspective. 

Canterbury

2017 saw Environment Canterbury (ECan) introduce Good Management Practices (GMP) into its Land and Water Plan framework.  This is known as Plan Change 5.  Plan Change 5 also introduced the Waitaki specific nutrient management rules.  The decisions on the plan were appealed by a number of parties, particularly in relation to how the irrigation and fertiliser GMP’s were being treated in the Farm Portal (the online tool developed to determine exactly what GMP is at a farm level).  Appeals are still yet to be resolved, and therefore, it is likely to be mid-2018 before this plan is made operative.

Plan Change 2, which is specific to the Hinds Plains region, is also still under appeal, however, Plan Change 3, which is specific to the South Canterbury Coastal Streams area, had all its appeals resolved in November 2017, and is now fully operative.

ECan has also been doing a big push in the areas where a consent to farm is required, to encourage those who need one to go through the process.  There has been a good response to this (contrary to the opinion of Dr. Mike Joy) as the process is new to many, and requires professional help and a change in mindset for many. 

Otago

Otago’s nutrient management rules are now two years away from kicking in (the date is 1 April 2020).  Otago Regional Council has been encouraging farmers to get their Overseer done.  They have also taken the initiative in the more sensitive catchments such as the Kakanui, and have been providing resources and funding to assist with this.

 

Southland

Southland’s Land and Water Plan is nearing the completion of hearings.  Council gave its reply report and recommendations (a summary of all the information and submissions presented to the hearings panel, and answers to all questions from the panel during the hearing) in November 2017.  Watch this space.

Horizons

Horizons One Plan struck a major hurdle in early 2017, with the Environment Court deciding that the way in which the Council was implementing its plan was not what the plan actually said.  This has left the council with a plan that effectively doesn’t practically work as it was written, and wondering what to do now.  Implementing the plan as written creates a massive cost to farmers and other consent holders, and doesn’t necessarily achieve the desired water quality outcomes.  Given this, in August 2017, the council voted to investigate the possibility of a partial plan change.  However, this will not be a quick or easy process as it is both a legal and public process.

Hawkes Bay

Irrigators in the Tukituki catchment are left high and dry (literally) after the Ruataniwha Dam project is put on the shelf indefinitely.  The Tukutuki River minimum flow is still going up, and without the dam to augment and flush the river, the increase in minimum flow will mean the possibility of severe restrictions for irrigators in this catchment.  Effectively, the raise in minimum flow was coupled with the dam, but the impacts of de-coupling are now about to be realised.

Gisborne

Gisborne’s Freshwater Plan decision was released in August 2017, and was subsequently appealed.  The appeals are still to be worked through and there is no timeframe at this stage on when appeals are likely to be resolved.  Gisborne’s Freshwater Plan was actually pretty kind from a nutrient management perspective when compared to Canterbury for example.  There is no requirement for on farm limits using Overseer, and they have adopted a Farm Environment Plan approach to managing water quality.  However, it does have some issues with water quantity.  As horticulture, and kiwifruit in particular, look set to increase, those looking in the Gisborne area for plots to develop are soon realising that there is basically no water available for allocation unless you are prepared to take high flow water and store it.  Therefore, this is limiting the potential for the Gisborne region.

Overall

As well as all that is going on the regions, we have a new government who looks set to wind up funding irrigation scheme development, has already taken a stand on climate change, and will undoubtedly want to stamp its feet on the water issues.  2018 will be an interesting year…

By Keri Johnston, Irricon Resource Solutions

Phone 0272 202 425 or email keri@irricon.co.nz

www.irricon.co.nz