Stock Exclusion - What's the go?

Out and about recently, Lilian Sherman, our North Island Rural Environmental Specialist, has heard a lot of discussion about the stock exclusion rules coming into play.  Unfortunately, a lot of what she has heard has had a serious dose of the ‘chinese whispers’ and the end result is that there are a lot of myths out there with regards to stock exclusion.  Below, Lilian dispels some of those myths and provides you with some confidence around the rules.

While there is no formal definition, stock exclusion generally means to exclude stock by some means from entering a waterbody.  In most cases, the stock exclusion definition does not include sheep or goats, as sheep and goats do not tend to linger in water!  In most cases the means of achieving stock exclusion is not specified, therefore the best method or technology for each situation can be used.  This may be a permanent fence, a hot wire, or as is currently being developed, virtual fencing.
Why is stock exclusion necessary? Stock entering waterways can cause significant damage by contributing nutrients (primarily nitrogen and phosphorus), sediment and faecal coliforms to our waterways. They do this though the direct deposition of dung and urine into rivers, treading damage and reduction in beneficial vegetation that results from grazing stream banks.

As part of the Clean Water package recently released by the Ministry for the Environment, there are proposed National Rules for Stock Exclusion.  Consultation on the proposed stock exclusion regulations and other aspects of the Clean Water package closed on 28 April 2017. This feedback is being considered and will inform the final decision on the National Rules.  The proposed stock exclusion rules are practical and there are different requirements for different classes of stock and for topography (plains, rolling and steep).  More details are available on the Ministry for the Environment Website (https://www.mfe.govt.nz/sites/default/files/media/Fresh%20water/next-steps-for-freshwater.pdf).

The proposed National Rules for Stock Exclusion recognise that for some landowners, there may be significant practical constraints that mean they are unable to meet the new requirements. In those cases, landowners can apply for permission to instead develop a stock exclusion plan with their regional council. The plan may include alternatives to fencing or mitigations to reduce the impact of stock access to waterways.  An example of this would be providing alternative areas of shade and reticulated stock drinking water, which may also provide other economic and animal health benefits.

It is important to note that the National Rules for Stock Exclusion will form the minimum requirements, and councils may choose to regulate over and above these in their regional plans.

There are some challenges excluding stock from waterways, including the effects of flooding, the proliferation of weeds and pests and access through vegetation to waterbodies.  These are valid issues and I have confidence that farmers will find practical solutions for these as the rules come into play.

In the meantime, if you are putting in new fence line or carrying out fencing maintenance, consider whether there is an opportunity to make a change to a fence line to exclude stock or make it easier to exclude stock in the future, but its also an important consideration for any development on farm such as irrigation (whether new or upgrading) and the location of waterways should be a key consideration in any design being undertaken. 

Keep an eye out for the final versions of the National Stock Exclusion Rules.

Lilian Sherman, Irricon Resource Solutions Limited.
Phone: (021) 378 308
E-mail: lilian@irricon.co.nz

Lilian is a Rural Environmental Specialist and Director at Irricon Resource Solutions, who works with farmers and horticulturists to prepare farm environment plans, resource consent applications and to assist with nutrient management and Overseer modelling. 

Lilian grew up on and lives on a sheep and beef farm, she has a practical knowledge of farming, including sheep, beef, deer, dairy, cropping and horticulture and combines her passion for farming with a wealth of nutrient management and environmental expertise in this role.

Legumes + Efficient Water Use = Great Results at Omarama Station

Omarama Station recently played host to the "Legumes in the High Country" field day, organised by Lincoln University and Beef + Lamb NZ. There was a good turnout of farmers and industry professionals to the farm owned and run by Richard and Annabelle Subtil, 2015 winners of the South Island Farmer of the Year competition. The focus for the day was the use of legume species in the high country environment with a short session on the use of irrigation and soil moisture monitoring in the arid environment that is the Mackenzie Country.

Omarama Station (Courtesty of Richard Subtil)

Omarama Station covers 12,000ha with a mixture of dryland high country and irrigated flats. The property has had significant development work undertaken and a number of centre pivot irrigators installed that irrigate 560ha. A large water storage pond has been constructed to supply water to the irrigation system.

Dr MS Srinivasan from NIWA gave the first presentation for the day at the site of the lysimeter that has recently been installed on the station. The lysimeter is the first in the Waitaki catchment and aims to build knowledge around drainage and soil water under the developing soils at Omarama Station. The site contains three catchment sleeves one of which has soil moisture sensors installed. Any drainage water from the site is measured which gives an indication of the soil moisture status and how drainage from the soil profile is taking place.

From a soil moisture point of view the lysimeter is important as the soils at Omarama Station have exceptionally variable fertility, structure and water holding capacity. Irrigation is not new to the area however the shift from border-dyke irrigation to more efficient spray irrigation has seen a massive change in the water use efficiency on extensive properties such as Omarama Station. Soil development under irrigation is an interesting concept and soils mapped on Omarama Station have shown to have varying levels of water holding capacity based on how long they have been irrigated for in the past. Investigation has shown that the depth of soil and the water holding capacity has improved under 30 years of irrigation. 

Irrigation at Omarama Station (Courtesy of Richard Subtil)

Agri Optics has installed three sub-surface AquaCheck probes that will complement the work being undertaken at the lysimeter site. This information will flow into the decision making process that is used around timing and quantity of irrigation water applied by the team at Omarama Station. 

Derrick Moot spoke on how selection of species was important to maximising water use efficiency in moisture deficient environments such as the Mackenzie Basin. As we know lucerne is a great fit into dryland high country systems. It has the ability to maximise the water use efficiency and has a high water to dry matter conversion ratio (kg DM/mm/ha). The selection of species going forward and the development of novel species all points towards maximising the efficiency of water use in dry high country areas.

Write up by Nick Evans