Mid Canterbury Research Articles

Interpreting the ‘rural mural’ phenomenon: Creative place-making in rural towns in South and Mid Canterbury, Aotearoa New Zealand

Consistent with discussions about public art and creative place-making in processes of rural settlement regeneration, this paper reports an enquiry into the recent appearance of large outdoor murals in several rural towns in the South and Mid Canterbury regions of Te Waipounamu the South Island of Aotearoa New Zealand. The enquiry is part of a larger study of rural settlement regeneration in which a variety of social, cultural, environmental, and economic revitalisation initiatives designed by local people are being interpreted. With that focus, our purpose in this paper is to describe and interpret the form and content of the murals under study and the ways they are used to distinguish places and their residents. Reflecting on the existing literature, which emphasises public art as a marker of place identity that is influenced by processes of commodification, we interpret the rural mural phenomenon as a key interlinked cultural and economic element in rural regeneration. Adding a policy dimension, we also examine the possibility of linking murals into wider networks of public art across Te Waipounamu the South Island.

A view on issues outside the farm gate that will influence the performance of hill country farming

Thank you for the invitation to be with you today and to participate in this symposium. As a recent newcomer to the ranks of hill country farming, I am looking forward to picking up some pointers I can take back to my small team at Mt Alford Station in Mid Canterbury. With academics and commentators speaking out strongly against the Trans Pacific Partnership (TPP), central Auckland traffic being brought to a standstill by protests around the signing of TPP on 4 February, global dairy prices slumping, and major daily fluctuations seemingly becoming normal in global stock markets, you could be forgiven for concluding that nothing is rational or normal anymore.

Heliohebe maccaskillii (Plantaginaceae)–a new rank for a threatened limestone endemic, North Canterbury, New Zealand

The limestone endemic Heliohebe raoulii subsp. maccaskillii is raised to species rank based on its distinctive morphology and ecological habitat, and its sympatry with H. raoulii subsp. raoulii. Unlike H. raoulii, which is widely distributed from Mid Canterbury to Marlborough, and is not threatened, H. maccaskillii is restricted to North Canterbury and its conservation ranking as Nationally Endangered is considered appropriate.

Salmonella Brandenburg - emergence of a new strain affecting stock and humans in the South Island of New Zealand

AIMS: To report information on the spread of a new strain of Salmonella Brandenburg, which affected livestock and humans in the South Island of New Zealand, and a series of small case studies designed to investigate potential transmission of infection. METHODS: Information on the occurrence and spread of S. Brandenburg in livestock was gathered from laboratory diagnostic submissions, from case studies on the faecal excretion rate in ewes, carrier status of black-backed gulls (Larus dominicanus), spread of S. Brandenburg organisms in sheep yards, infection in lambs going to meat plants, and from post-abortion pathological changes in the reproductive tract of ewes. RESULTS: A newly recognised strain of S. Brandenburg was first diagnosed in aborting sheep from a flock in mid Canterbury in the South Island in 1996. Subsequently, the disease spread to other farms in mid and south Canterbury in 1997 and to Southland and Otago in the lower half of the South Island in 1998–2003. In 1999, the same strain was responsible for abortions in cattle and gastroenteritis in calves and adult cattle. The same strain of bacterium also caused disease in horses, goats, deer, pigs and humans. Spread of the disease on farms was strongly associated with aborting ewes, which resulted in considerable environmental contamination. During the abortion season, black-backed gulls appeared to spread the disease to other farms. Other potential sources of infection were carrier sheep, contaminated water sources and contaminated sheep-yard dust. Damage to the reproductive tract may affect the ability of surviving ewes to conceive. CONCLUSION: Important features of this disease are its high morbidity and mortality within a flock or herd, rapid local spread and its role as an occupational, health and safety risk to farm workers and their families.

Introduction to farming in the Central Canterbury area

On the east side of the Southern Alps of the South Island lies the province of Canterbury. Within this province there are five district regions, North, Central, Mid, and South Canterbury (all running from the mountains to the sea and separated by major rivers), and Banks Peninsula. Central and Mid Canterbury are home to the Selwyn and Ashburton District Councils (respectively) and sit side by side in the centre of Canterbury. Selwyn District has a northern boundary with the Waimakariri River, Christchurch City, and Banks Peninsula. Ashburton District has a southern boundary with the Rangitata River. The mighty braided Rakaia River is the dividing boundary between the two districts. Canterbury Regional Council (ECAN), based in Christchurch, has control over environmental issues in the area.

White clover: loss in drought and subsequent recovery

There are limitations to the production and persistence of white clover in drought prone regions. We report on the population dynamics of white clover during the summer/autumn drought of 2000. Seventeen paddocks were selected from Marlborough, Mid Canterbury, South Canterbury and North Otago on the east coast of the South Island, and Wairarapa in the North Island. The pastures were sown in 1998/99 and are comprised of ryegrass, tall fescue, cocksfoot or combinations of these as the grass base, with white clover included in the mix. White clover populations were monitored pre- and post-drought using tiller cores. The percentage of each region's long-term mean rainfall received during the 6-month "drought period" had the largest influence on the presence of white clover in these pastures. Marlborough, with only 73 mm of rainfall during November 2000-April 2001 (23% of its expected rainfall) suffered a 95% reduction in white clover. Mid Canterbury, South Canterbury and North Otago, at 53-61% of expected rainfall had a 40-78% loss. In contrast, Wairarapa, with 303 mm of rainfall, lost only 8%. The rate of recovery was closely related to the magnitude of white clover loss during drought. In regions where large losses occurred, further sampling after 18 months showed little increase in white clover presence. Key words: drought, persistence, populations, seedling, Trifolium repens, white clover

Possible Jurassic age for part of Rakaia Terrane: Implications for tectonic development of the Torlesse accretionary prism

Greywacke sandstone and argillite beds comprising Rakaia Terrane (Torlesse Complex) in mid Canterbury, South Island, New Zealand, are widely regarded as Late Triassic (Norian) in age based on the occurrence of Torlessia trace fossils, Monotis, and other taxa. This paleontological age assignment is tested using published 40Ar/39Ar mica and U‐Pb zircon ages for these rocks and published and new zircon fission track (FT) ages. The youngest U‐Pb zircon ages in the Rakaia Terrane rocks in mid Canterbury are Norian, whereas 10–20% of the 40Ar/ 39Ar muscovite ages are younger than Norian. Numerical modelling of these mica ages shows that they cannot have originated from partial thermal overprinting in the Torlesse prism if the thermal maximum was short‐lived and early in the prism history (210–190 Ma), as commonly inferred for these rocks. The young component of mica ages could, however, be explained by extended residence (200–100 Ma) at 265–290°C in the prism. Early Jurassic (c. 189 Ma) zircon FT ages for sandstone beds from Arthur's Pass, the Rakaia valley, and the Hermitage (Mt Cook) are interpreted not to have experienced maximum temperatures above 210°C, and therefore cannot have been reduced as a result of partial annealing in the Torlesse prism. This is based on identification of a fossil Cretaceous, zircon FT, partial annealing zone in low‐grade schists to the west, and the characteristics of the age data. The Early Jurassic zircon FT ages and the young component of 40Ar/39Ar mica ages are regarded therefore as detrital ages reflecting cooling in the source area, and constrain the maximum depositional age of parts of the Rakaia Terrane in mid Canterbury. The zircon FT data also show the initiation (c. 100 Ma) of marked and widespread Late Cretaceous cooling of Rakaia Terrane throughout Canterbury, which is attributed to uplift and erosion of inboard parts of the Torlesse prism due to continuing subduction accretion at its toe. The critical wedge concept is proposed as a new framework for investigating the development of the Torlesse Complex. The Rakaia Terrane may have formed the core of an accretionary wedge imbricated against the New Zealand margin during the Middle or Late Jurassic. Late Jurassic nonmarine sediments (e.g., Clent Hills Formation) accumulated upon the inner parts of the prism as it enlarged, emerged, and continued to be imbricated. Exhumation of Otago Schist from c. 135 Ma may mark the development of a balance (steady state) between sediments entering the prism at the toe and material exiting at the inboard margin. The enlargement of the area of exhumation to all of Canterbury from c. 100 Ma may reflect a dynamic response to widening of the prism through the accretion of Cretaceous sediments. The model of a dynamic critical wedge may help to explain the various expressions of the Rangitata Orogeny.

Regional patterns of plant species richness in southern New Zealand

We examine the proposition that spatial heterogeneity, as modelled by land area, productivity‐influencing climatic variables, and elevation, is a usefd predictor of regional patterns of species richness in 56 regions of southern New Zealand stretching from mid Canterbury to Campbell Island. We also examine whether regional patterns of taxonomic richness support the concept of a Late Cenozoic radiation of upland floras and that this was sourced from just a few genera in a few widespread to cosmopolitan families. We found several contrasting geographical patterns in taxonomic richness. Several mainly mountain regions just east of the main divide in western Canterbury, Otago, and Southland are unusually species‐rich, but not genus‐ or family‐rich. Conversely, several coastal regions of eastern South Island are unusually genus‐ and family‐rich, but not species‐rich. Four geographically distinct groups of regions share relatively species‐, genus‐, and family‐depauperate floras: maritime‐influenced regions of Fiordland, the Chatham and subantarctic islands, inland and lowland basins of Otago and Southland, and eastern Otago's block mountains. Various combinations of elevation range, climatic variability, and land area explain 54% to 61% of the variability in richness of species, genera, families, and life‐form groups. Mean daily temperature of the coldest month appears the strongest climatic variable at depressing floristic richness, although moderate degrees of continentality of climate increase it. We conclude that both propositions are supported by the present study. Databases of regional‐scale patterns of plant species richness should be useful for selecting mainland islands for ecosystem restoration, estimating ecosystem or guild diversity, and testing the ecological distinctiveness of ecological regions and districts.

The effect of removal technique and post‐removal handling on velvet antler colour

Asian markets for velvet antler perceive the colour of the core as a primary indicator of quality. The factors which influence colour are not known, but the market preference in Korea is for an even mid‐red colour. The aim of the present study was to determine whether removal technique and post‐removal handling influence velvet colour. Investigations took place at AgResearch Invermay and at Mount Hurt Station in mid Canterbury, New Zealand. The influences on velvet antler colour of sedative drug, mild stress, local anaesthetic administration, timing of tourniquet application, and restraint of the stags in a crush or workroom for velvet antler removal were investigated. The effects of antler orientation post‐removal and post‐removal environmental temperature on velvet antler colour were also investigated. In all studies, velvet antler was frozen and held at ‐20°C before being dried either by freeze drying or commercially. In all trials, a consistent pattern of both lightness and hue angle was shown from the tip of the velvet antler stick to the base; the tip was lighter and browner, the mid section was darker and redder, and the base was lighter and browner. There were no significant overall effects of drug treatment on colour, but there were significant differences among sections. Specifically, sedative drug treatments resulted in less red velvet antler than in control antlers removed using local analgesic only. Mild stress and method of local analgesic administration had no effect on any aspect of velvet antler colour. Placing the velvet at an angle of 15° (tip down) gave a darker and redder antler than the typical fully inverted position. There were no significant differences in colour whether the velvet antler was frozen immediately after removal or held at 4°C or ambient temperature for up to 6 hours prior to freezing. Overall, the use of sedative drugs produces velvet antler that is lighter and less red, and post‐removal handling technique can influence colour.

Structure and neotectonics on the Main Divide, upper Wilberforce valley, mid Canterbury, New Zealand

The upper Wilberforce valley drains the Main Divide of the northern portion of the actively rising Southern Alps. The Wilberforce area lies in a transition zone between oblique convergence to the south and a predominantly strike‐slip segment to the north. The structure of the area is dominated by the 2 km wide, currently active, Main Divide Fault Zone (MDFZ), which strikes northeast and consists of two main strands. The western strand crosses the Main Divide at Browning Pass and dies out northwards. The eastern strand runs parallel to the Main Divide immediately east of the divide in the upper Wilberforce valley and then crosses the divide farther north. A broad region of relatively low relief and topography at Browning Pass has developed between the two fault strands. The MDFZ was initially dominated by southeast‐directed oblique reverse faulting. Neotectonic features in the Browning Pass area, between the two fault strands, show dextral strike‐slip motion with as much as 50 m horizontal displacement affecting recently deglaciated surfaces but <10 m of vertical displacement. South of the MDFZ, the structure of the area is dominated by north‐striking faults which intersect the MDFZ immediately east of the divide. These faults are subparallel to bedding in the host Torlesse Terrane sediments, and faults and bedding control topography. Bedding becomes rotated subparallel to the MDFZ along the Main Divide. A spaced cleavage in metasediments on the hanging wall of the MDFZ may indicate that the hanging‐wall rocks are of higher textural grade than the textural zone I footwall rocks.

The effect of pasture species on pasture and animal performances in irrigated systems

The effect of two contrasting forage supply options on forage and sheep production was evaluated on irrigated farmlet systems at Winchmore, mid Canterbury, over 3 years. One system was based on perennial ryegrass pastures (Control), and the other on hybrid ryegrass, tall fescue, and chicory pastures (Improved). Pasture growth rates were similar for all pasture types, however, pasture cover was on occasion, higher on the Control than Improved systems ensuring this system was self-sufficient in feed while the Improved system had a deficit averaging 714 kgDM/ha/yr. Swards on both systems contained similar proportions of legume but the Improved system contained less grass and more chicory before lamb grazing. Despite the apparent improvement in feed quality of the Improved system, its lamb performance was greater than that from the Control system for the first year only, when swards were newly established and contained greater proportions of chicory and legume. Although pasture production was similar between years there was considerable variation in lamb growth rates. This was most pronounced in the Improved system where pre-weaning rates averaged 266 and 216 g/d in years 1 and 3 respectively, and post-weaning rates 190 and 108 in years 1 and 2 respectively. The post-weaning variation appeared to coincide with fluctuations in clover and to an even greater extent, the chicory content of swards, the proportion of which declined as seasons progressed and pastures aged. The Improved system gave financial returns from lamb that were $49/ha higher than the Control in year 1 but offered no advantage in subsequent years. Compared to the Control, the Improved system had the added costs of more frequent pasture renewal and was further disadvantaged by a feed deficit necessitating buying-in supplies. Improvements anticipated to accrue from the inclusion of higher quality swards in an irrigated animal production system, were not supported by findings from this study. Keywords: irrigation, lamb production, pasture production, pasture quality, pasture species

Distribution of three Hieracium species in the Mt Possession area, mid Canterbury, New Zealand

The abundance of three Hieracium species was examined in the Mt Possession area in relation to soil and other site variables. For H. pilosella cover, total soil P and elevation were the most significant combined predictors, but together explained only 30% of the variation. H. Pilosella had the highest coveer at relatively high P levels and at low elevation. The presence of H. praealtum was predicted by moisture index, while that of H. caespitosum was predicted by tussock height and C:N ratio in the soil. However, none of the measured site variables significantly predicted the cover of H. praealtum and H. caespitosum. The present cover distributions of H. pilosella and H. praealtum were compared with a 1960s survey in the area. The distribution of H. pilosella cover frequency had changed from being skewed with the species absent or in low cover in 1960s, to becoming common and the coer frequency for H. pilosella showing a normal distribution with the highest frequency at cover class 2 (5-25% cover). H. praealtum was absent or in relatively low cover in both surveys. The P response curve for H. Pilosella contradicts other studies, and shows the need for specificity about what environment and vegetation are studied. the differences in spatial and temporal variation among the three Hieracium species also emphasise the need to consider them separately when discussing their ecology and management.

Further investigations of the black currant reversion disease in New Zealand

An evaluation of several black currant (Ribes nigrum L.) cultivars recommended or suggested as indicators for the reversion disease, showed ‘Baldwin’ to be the most sensitive. ‘Kentish Hero’ and ‘Silvergieters Schwarze’ were almost as sensitive as ‘Baldwin’, but ‘Ojebyn’ did not express definitive symptoms. A virulent strain of reversion found in the cultivar ‘Kentish Hero’ appears similar to the V1 strain reported in England. Moderate, and possibly mild, strains occurred in several other cultivars. However, the severe “R” form of the disease causing the split sepal symptom of black currants in Scandinavia and Eastern Europe does not appear to be present in New Zealand. Surveys in 1990, 1991, and 1996 of commercial properties growing black currants in the South Island showed that reversion was present in several plantings in South Canterbury and Otago, and was widespread in Southland plantings. A low incidence of reversion in Nelson is thought to have been eliminated by the removal of infected plants. North Canterbury plantings remain free from infection, but infection has appeared at two locations in mid Canterbury. Spread of infection between properties was initially caused through the inadvertent use of infected propagation material, and further spread within properties by the gall mite (Cecidophyopis ribis Westw.) vector. The use of gall mite resistant cultivars appears to be the only effective means for the control of reversion.

Nationwide survey of pests and diseases of cereal and grass seed crops in New Zealand. 1. Arthropods and molluscs.

A national survey of four cereal and two grass seed crops was conducted by the New Zealand Plant Protection Centre (NZPPC) from October 1995 to February 1996. Approximately 85,000 plants were inspected at 332 sites in the main cereal growing areas of New Zealand. In addition to the previously known invertebrate species associated with cereal and grass seed crops, 93 new organism-host associations were recorded for wheat (21 primary pests), 85 new associations for barley (22 primary pests), 40 new associations for oats (8 primary pests), 25 new associations for ryecorn (3 primary pests), 57 new associations for ryegrass (15 primary pests) and 29 new associations for brome grass (5 primary pests). Cereal thrips (Limothrips cerealium), wheat sheath miner (Cerodontha australis) and Argentine stem weevil (Listronotus bonariensis) were the most common pests found in this survey. Chamaemyia polystigma, a predatory fly new to New Zealand, was recorded on barley, brome grass and ryegrass. One undescribed species of Thysanoptera was found on wheat from Mid Canterbury.

Soil nutrient distribution in pastures flood‐irrigated by the border strip method

Two studies of the distribution of the levels of the nutrients phosphate, sulphate, potassium, magnesium, sodium, calcium, and of pH levels, were carried out in sheep pastures that were flood‐irrigated by the border strip method in mid Canterbury, New Zealand. The border strips had been formed by grading the land to a gently sloping plane surface, then creating c. 12 m‐wide, 200–300 m long strips by raising “borders” c. 1.8 m wide and c. 12 m apart, with strips aligned with the direction of maximum fall. The first study involved four 30‐year‐old border‐strip pastures at Winch‐more Research Station, whereas the second study involved 20 border‐strip pastures of varying age on nine commercial farms in Ashburton County. In both instances 75 nun‐deep soil samples were taken from the tops of the irrigation borders and from the border crutches and strips, at varying positions up and down the length of the border‐strip systems. In both studies nutrient levels were in general lowest in the strips, highest in the crutches, and intermediate on the borders. These differences are presumed to have been caused by stock camping on the borders and in the crutches, and the movement of faeces by irrigation water. A practical outcome of the study is the conclusion that fertiliser and lime applications can be restricted to the strips.

Stratigraphic and petrological variation of the Mount Somers Volcanics Group, mid Canterbury, New Zealand

Abstract Mt Somers, mid Canterbury, New Zealand, consists of seven temporally distinct Upper Cretaceous volcanic formations which together form the Mount Somers Volcanics Group. These formations are the Surrey Hills Tuff, Barrosa Andesite, Woolshed Creek Ignimbrite (new name), Somers Rhyolite, Somers Ignimbrite (new name), volcanic conglomerates and tuffs, and Hinds River Dacite. Surrey Hills Tuff comprises both massive and bedded rhyolitic tuff and records the first explosive silicic volcanism at Mt Somers. Barrosa Andesite occurs as porphyritic pyroxene andesite flows, breccias, and shallow intrusives in the north and northwest of the area and is considered to represent an eroded stratocone. The main period of silicic volcanism began with the formation of Woolshed Creek Ignimbrite, a black, glassy, porphyritic vitrophyre containing up to 15% lithic fragments. Its massive, glassy nature is due to fusion by the overlying Somers Rhyolite, which comprises nearly 1000 m thickness of coalesced rhyolite lava d...

The key to successful second year white clover seed crops

In recent years there has been an increase in the number of white clover seed crops taken for a second harvest. Traditionally yields from second year crops are substantially lower than first year crops. A trial was established investigating techniques to increase yields in second year crops. The trial was located in a dryland crop of white clover (cv. Grasslands Demand) 4 km east of Methven, mid Canterbury. It involved 10 herbicide treatments and 8 'inter-row' treatments arranged in a split block design. Number of mature flower heads were recorded on all treatments at harvest as an indirect estimate of yield. Additionally, selected treatments were cut and collected using a rotary type mower, threshed, and machine dressed for direct estimates of seed yield. Flower number and machine dressed seed yield were significantly (P

Evaluation of dryland forage species for lowland Marlborough and 'Mid Canterbury

Grazing trials were established at Dashwood, Marlborough and at Winchmore Research Station, Mid Canterbury, to determine persistence, production patterns and changes in composition of various dryland pasture species. Plots were individually fenced and grazed to optimise individual species performance. At Dashwood (Dashwood shallow silt loam and stony loam, 600 mm rainfall), nine species were established: ryegrasses (Grasslands Supernui, Grasslands Nui, and a local ecotype), cocksfoot (Grasslands Wana), phalaris (Grasslands Maru), bromes (Grasslands Tiki and Grasslands Hakari), wheatgrass (Grasslands Luna), and a luceme/phalaris mix (Grasslands Otaio Maru). All species were sown with white clover (Grasslands Tahora) and red clover (Grasslands Pawera). Interim results of the first 3 years show ryegrass species Supernui, Nui and the local ecotype established well in the first year but are gradually being surpassed by the slower establishing species such as Mar-u, Wana and Otaio lucerne. The Winchmore project (Lismore stony silt-loam 739mm rainfall) included 11 species: lucerne (Grasslands Otaio), sheep's burnet, birdsfoot trefoil (Grasslands Goldie), red clover (Grasslands Colenso), browntop (Grasslands Muster), chicory (Grasslands Puna), wheatgrass (Grasslands Luna), ryegrass (Grasslands Pacific), smooth brome (Grasslands Tiki), upland brome (Grasslands Hakari) and grazing brome (Grasslands Gala). Over the first three years Otaio has remained as one of the best producers, but Colenso and Tiki, while producing well in the first year havedropped considerably by year three. Results demonstrate that there is potential for some species tested to enhance the production on the light east coast soils in the South Island but in the long-term persistence must be monitored. Keywords: dryland, pasture species, pasture composition, pasture yield

Nitrogen use on Canterbury dryland pastures

Results from the first two years of a farmlet trial carried out on a dryland Lismore soil near Ashburton, Mid Canterbury are reported. Farmlet treatments were 0, 25 (25 N) and 50 (50 N) kg N/ha applied as urea in mid-April of 1992 and 1993. Stocking rates for each farmlet were 9.5, 10.5 and 11.5 (Year l), and 11, 12 and 13/ha Borderdale ewes/ha (Year 2). For both years of the trial, there were small increases in mean pasture cover from N use despite the higher stocking rates on the N farmlets. Both mean clover content (14%) and N fixation rates (36 kg N/ha/year) were low but only declined slightly with N use. Average lamb carcass weight was lower on the 25 N and 50 N farmlet than the nil N farmlet (16.9 cf 18.3 kg). Despite this decrease, lamb carcass production per ha was significantly higher on the 50 N farmlet (216 kg/ha) compared with the nil N farmlet (199 kg/ha), Similar wool weights per ewe between farmlets resulted in an increase in wool production per ha from both N farmlets (25 N - 34.9 kg/ha, 50 N - 38 kg/ha) compared to nil N (30.8 kg/ha). Keywords: clover content, lamb production, nitrogen fertiliser, nitrogen fixation, stocking rate, wool production

Productivity and water use of an irrigated high country pasture

Pasture production and irrigation water-use efficiencies were measured for 3 irrigation regimes on a Mackenzie shallow, stony soil in the Mackenzie Basin near Omarama. Irrigating at 25% was the most efficient of three irrigation frequencies maintained over the 198 1-1986 period (irrigated at O%, 25%, and 50% plant-available water capacity). Less frequent irrigation resulted in lower pasture yields due to increased water stress, while more frequent watering resulted in a 55% drainage loss of irrigation water below the root zone. At 1.16 t DIvUha per irrigation, the increase in pasture yield with irrigation at 25% was higher than most increases achieved in existing irrigation schemes in Central Otago and mid Canterbury. Over 6 years, this treatment required 4-7 irrigations annually and, on average, produced 6.0 t DM/ha more than did dryland pasture. The water-use efficiencies achieved in the border-strip irrigation system used were generally greater than expected for highly permeable stony soils where large drainage losses of irrigation water below the root zone are common. This was the result of reduced soil water transmission rates after compaction by heavy machinery during border strip* preparation. That effect of compaction was persistent, and had not diminished 9 years after initial pasture and irrigation development, as structural improvement of this soil is slow, even under irrigation. Keywords: high country pasture, irrigation, Mackenzie Basin