Dealing with salinity in Wheatbelt Valleys - Department of Water

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PROFITABLE, SUSTAINABLE SALTLAND PASTURES? GET REAL! INTRODUCTION Saltland has received negative publicity over the last decade, mainly for two reasons. Firstly, research results of feeding trials in the early 1990s indicated that saltbush alone had little feed value. As a result, the media trumpeted that “saltbush is useless!” Secondly, doubt had been cast on the ability of saltbush and other halophytic perennials to use significant quantities of groundwater. In 1997, a group of farmers and researchers formed the Saltland Pastures Association (Inc.) to demonstrate that, in a practical whole farm situation, saltland is a profitable sustainable resource which can be developed. This paper details the experiences on one farm, “Bundilla”, which is typical of the broad valley floors in the Wheatbelt of Western Australia. It discusses the options available in the late 1980s and gives reasons for a revegetation approach being taken. Information is provided on the types of revegetation, the production obtained and the environmental and other benefits achieved, to show the profitability and sustainability of saltland pastures. As well, it will briefly discuss further opportunities available for animal production from saltland, in both extensive and intensive production systems, and explore other productive uses of saltland and saline water. “BUNDILLA” – AN EXAMPLE “Bundilla” was originally selected in the early 1920s when the district was opened for settlement, but only a small area was cleared at that time. By the late 1950s, most of this had regrown. From 1960 to 1968, “Bundilla” was progressively cleared of most of the native perennial vegetation, with only non-arable areas Michael Lloyd 1 1 Chairman, Saltland Pastures Association (Inc.), “Bundilla”, Private Mail Bag, Lake Grace WA 6353 – 1 – Lloyd (such as granite outcrops and a few small lakes) and shelter areas left uncleared. Typical of the broad valley floors in inland Western Australia, “Bundilla” has large areas of low-lying duplex soils. By the mid 1970s, salt began to appear in areas that, 15 years earlier, had grown above average wheat crops. Over the next 15 years, increasing salinisation reduced the arable area on “Bundilla” from 1,800 Ha to fewer than 1,000 Ha. It was clear that something had to be done. The traditional solution was to either sell to a neighbour or buy more land. For a variety of reasons (not the least of which was my stubborn nature), it was decided to stay and attempt to solve the problem, to try and get some production from the saltland. OPTIONS Three options were considered: a) Drain or Pump The drainage/pumping option was considered too expensive for the potential benefit. Together with the high cost was the fact that the very tight, water-holding clays may not transmit significant quantities of groundwater laterally. As one farmer put it: “If water will not flow laterally out of a dam into the surrounding soil, why would it flow out of the surrounding soil into a drain?” Difficulty in property management, increased fencing costs and aesthetics also played a part in the decision not to proceed with this option. Was it solving the problem, or just transferring it downstream for someone else to deal with? Legal implications also existed with the disposal of the saline groundwater. When enquiries were made in the late 1980s, it was discovered that there were a
Lloyd number of legal cases pending regarding the disposal of the groundwater from drains and pumps. b) Plant Trees Trees seemed to be an alternative, though advice received suggested that most would eventually die. An area of Eucalyptus sargentii was planted in 1989, and to date most have survived. Certainly they have lowered the water tables in the area and do provide shelter for stock. However, as these trees seem to have significant surface roots, there is nothing growing within 2 m of the base of the trees, although there is some extra production in the alleys away from the trees. Furthermore, there is no commercial production opportunity from these trees themselves; even though they look “nice”. For “Bundilla” to remain a viable farming operation, this saltland had to become more productive. c) Plant Saltbush Saltbush seemed to be the answer. At the time it was considered to be good fodder with increased value for its “out of season” production and it would use groundwater. Reports from research at the University of Western Australia suggested that feed produced in autumn had up to 14 times the value of feed produced in the spring. Saltbush would provide shelter and be aesthetically pleasing. The WA Department of Agriculture had done significant work in developing saltbush. Researchers had scoured the world for different species to introduce into Western Australia. It seemed to be the perfect solution! THE WAY FORWARD After attending a field day in 1989 and seeing what could be done with saltbush, a machine was hired and a small area (17 Ha) was seeded. This area grew well. A direct seeding niche machine was purchased in 1990, and so the saga began. Now “Bundilla” has nearly 600 Ha of revegetated saltland upon which sheep are happily grazing. In fact, if it weren’t for the saltbush, “Bundilla” would only be able to carry half the current number of sheep. The dry season in 2001 has demonstrated the value of saltbush, with normal sheep numbers being carried through the autumn/winter period. Apart from small areas of seedlings planted in 1989 and 1998, all saltbush has been direct seeded, using the niche-seeding machine. This machine – 2 – rips, mounds and places a seed/mulch mixture every two metres in a niche formed on top of the mound. We normally expect well in excess of a 100% strike rate (i.e. more than one plant for every seed placement). There would be in excess of one million saltbush shrubs on “Bundilla". Original species included Atriplex amnicola, A. nummularia, A. lentiformis, A. undulata, A. semibaccata and Acacia saligna. In the latter years, generally Atriplex amnicola (a low success rate when direct seeding) and A. lentiformis (short life span) have been eliminated. A. semibaccata is native to the region, and along with Maireana brevifolia, grows naturally and so is not included in the seed mix. While the direct seeding/niche method of planting has not changed over the ensuing period, row spacings have varied. Originally, we planted the rows as close together as we could (remember that we thought it was good fodder!). We tried leaving gaps every 5 rows to correspond with boomspray widths, then extended the non-seeded areas and reduced the number of rows progressively until we have the present arrangement of two rows of saltbush with 9 metres between the double rows. There are plans in 2001 to establish a trial to determine the optimum alley width. From 1991, Paradana balansa, tall wheat grass, and puccinellia were sown with the saltbush in each spring. However, these plants rely on a long wet season the following year to establish. Unfortunately, production was generally less than satisfactory and this has now been discontinued. CHANGES But how things have changed! Following press reports of the Warren-Casson work in 1994 (Warren & Casson 1994), the role of saltbush had to be re-evaluated. If there was little fodder value in saltbush, why was it that we were grazing more sheep on the saline areas? Why did we have more wool? Why had the quality improved? The answer appears to be twofold: 1) There was an increase in the understory fodder plants – sub clover, rye grass and capeweed returned to supplement the barley grass and native clover.
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Foreword Dealing with Salinity in W
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1Day one: Monday 30th July. Field t
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Papers Dealing with Salinity in Whe
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Ali and Coles biggest challenges fa
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Ali and Coles erosion, maintenance
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Ali and Coles expected under these
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Ali and Coles Coles, N.A. & Ali, M.
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Commander, Schoknecht, Verboom and
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APPRECIATING AND CREATING OUR HISTO
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services. The Government responded
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Page 51 and 52: REFERENCES Agstats (1997). Agricult
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Page 73 and 74: Hatton and Ruprecht WATCHING THE RI
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Page 105 and 106: INTRODUCTION The Lake Chinocup Catc
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Page 131 and 132: Pannell Pannell, D.J. (2001). Dryla
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Porter, Bartle and Cooper that is a
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CASE STUDY - TOOLIBIN LAKE AND CATC
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• The distribution, storage and m
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Secondly, there is a set of practic
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within three categories: relationsh
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CONCLUSIONS Actions to protect and
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FIELD TOUR LOCATIONS FIELD TOUR NOT
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COLES FARM “Avon River Basin Over
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Conference Outcomes Dealing with Sa
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with Salinity in Wheatbelt Valleys:
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with Salinity in Wheatbelt Valleys
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Photo Gallery 2 Dealing with Salini
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APPENDIX 1 BACKGROUND HYDROLOGY AND
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WHEATBELT HYDROLOGY Flow in the Yil
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Flow (ML) STREAM SALINITY Salt Rive
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APPENDIX 2 WATER MANAGEMENT OPTIONS
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APPENDIX 3 MANAGING WATER AND SALIN
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SUMMARY- TIMELINE OF RECENT SIGNIFI
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RECENT HISTORY OF WATER AND SALINIT
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Figure 1. Hydrological cross-sectio
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Depth (m) 316 315 314 313 312 311 M
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FURTHER INVESTIGATIONS AND MANAGEME
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Dealing with salinity in Wheatbelt Valleys - Department of Water

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