bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing environmental monitoring tools from sustainability indicators in the southern Riverina
Authors: Ridley A. M. , Paramore T. R. , Beverly C. R. , Dunin F. X. , Froelich V. M. C.
Published: August 2003

This paper outlines work being undertaken with farmers in the Riverina of New South Wales to develop practical tools to help assess and monitor on-farm environmental performance. A Participatory Learning and Action Research approach was used which combined farmers' knowledge and interest in the environment with previous research undertaken on water losses in cropping systems. The hypothesis tested was 'that current water sustainability indicators developed by scientists were of limited use for on-farm application'. Using the participatory approach, 2 monitoring tools were produced and the approach was illustrated using a 'learning cycle'. The first tool assessed so-called 'perenniality' on a whole farm basis. The second tool allowed farmers to assess the 'leakiness' (losses of water below the root zone of farming systems) of a paddock in a particular year using farmers' rainfall records, assessment of soil type and assumptions about the ability of plant species grown to dry out the soil. Water related sustainability indicators developed by scientists were not particularly useful in helping farmers assess their environmental performance. Using a participatory approach was a valuable way to develop environmental monitoring tools with participants learning much in the process.
The application of sustainability concepts to Australian agriculture: an overview
Authors: Stoneham G. , Eigenraam M. , Ridley A. , Barr N.
Published: August 2003

This paper reviews the concepts of sustainable development in an economic, environmental and social context. Weak and strong versions of sustainable development are reviewed and applied to the agricultural sector. The paper demonstrates that despite any degradation of the natural resource base, the agricultural sector is more productive now than in the past. This has occurred because the rate of investment in research and development (resulting in increased reproducible capital) has more than offset the rate of degradation in the natural capital stock. Science, it is argued, is part of the economic system that allocates productive capacity between current and future generations. Increases in expenditure on agricultural R&D since the 1950s have ensured that past generations have transferred productive capacity to future generations. With respect to the environment, the authors argue that a strong version of sustainable development may be appropriate, particularly where there are uncertain and irreversible outcomes. Finally, it has been observed that a hybrid version of social sustainability has been adopted in Australia. While resource mobility in the agricultural sector has been generally encouraged (weak sustainability) this has been underpinned by a welfare system that ensures basic standards of well-being and opportunity (strong sustainability).
Characterisation of farmers' soil sense and the implications for on-farm monitoring of soil health
Authors: Bruyn L. A. Lobry de , Abbey J. A.
Published: August 2003

If farmers are to determine whether their farm goals for resource condition are being met, and whether changes in farm management are leading towards a more sustainable farming system, then they need to be able to monitor these areas. Yet to date, an easy to use, practical and reliable method to be used by farmers to monitor trends in soil health has not been developed. This has been a consequence mainly of developing soil monitoring packages in isolation from the end user, and relying on 'expert' advice to guide farmers' management of the soil rather than empowering them to be more self-reliant in this area. This study sought to collaborate with farmers in the development of a soil health checklist. The research process acknowledged the importance of local conditions, farmers' existing knowledge on soils and their preferences for delivery and presentation of the final product. The study focused on farmers located in the north-west cropping region of New South Wales, Australia. This article reports on a prototype for a farmer's soil health checklist — the features they use, how they recognise those features, especially the language they use to describe a healthy and unhealthy soil, and finally the techniques they use to determine those features.
Where, and how, do monitoring and sustainability indicators fit into environmental management systems?
Authors: Carruthers G. , Tinning G.
Published: August 2003

Despite the availability of numerous 'sustainability indicators' (as defined by researchers and resource-management agency staff), many farmers do not routinely use these indicators for monitoring and measurement of their everyday farm management. Farmers' past experiences with such indicators have often been through their use by researchers (trying to evaluate effects of management or quantify resource condition changes) or other external bodies (usually regulatory agencies endeavouring to regulate environmental impacts). Such experiences have added little or nothing to on-farm management. Rather, farmers often rely on a diverse range of personally relevant indicators to assess the performance of their farm business. Such indicators may not be recognised by others as indicative of sustainability. The process used in environmental management systems (EMS) implementation is predicated on the need for information to flow back to the manager to assist their management choices. In this way, the indicators of most use are those that the manager can determine and utilise. This paper describes the connection between environmental management systems, monitoring and indicators, and the importance of these linkages to the efficient and sustainable management of natural resources. It discusses a collaborative project between in New South Wales and Queensland grain farmers, and NSW Agriculture, to develop generic EMS guidelines based on the international standard for EMS, ISO 14001. While there are numerous recommended sustainability indicators, research with these farmers has found that it is more critical to determine which issues are of importance to the farmers and identify potential indicators they will utilise, rather than to recommend a prescribed suite of indicators. In some cases, these indicators may be of a larger-scale than just their property.Different users of resource-management information will require different indicators. The use of the EMS process provides structure and guidance in determining which of the plethora of indicators might be applicable, while allowing farmers to maximise benefits in the market place or the community. Resource-management agencies and customers may require a different suite of indicators. The use of EMS assists in streamlining all these demands, while keeping the focus on the management approaches required to achieve the greatest benefit for the manager.
Application of sustainability indicators, soil organic matter and electrical conductivity, to resource management in the northern grains region
Authors: Dalal R. C. , Eberhard R. , Grantham T. , Mayer D. G.
Published: August 2003

Sustainability is a multifaceted concept. It is expressed here as 'to ensure that the past and current management and use of natural resources does not diminish their capacity to meet economic, environmental, social and aesthetic needs and opportunities of the present and future generations'. Sustainability indicators can be used to monitor responses in condition and trend as a result of natural resource management. We report here 2 case studies that demonstrate the significance of sustainability indicators in discerning trends in land and water resources in the southern Brigalow (Acacia harpophylla) Belt, a major region of the Queensland Murray–Darling Basin. First, soil organic matter was used as a sustainability indicator of soil productivity, soil aggregation, and its association with soil sodicity since these soil attributes affect infiltration rates, runoff and drainage. The second study involved comparing the trends in stream salinity (electrical conductivity) over 35 years and sustainability indicators for a dominant Vertosol in a region used for cereal cropping. Groundwater level and electrical conductivity of a long-term monitoring bore in the Dalby–Chinchilla region, were also analysed to discern trends in salinity and association of the groundwater with soil and stream salinity. Soil organic matter declined exponentially as the cultivation period for cereal cropping increased. This resulted in a reduction in soil nitrogen supply, and lower grain protein and cereal grain yields. The associated effects were reduced soil aggregation and increased soil sodicity. Electrical conductivity of the soil as well as stream water showed weak but declining trends with time. Groundwater level from the long-term monitoring bore near the stream and groundwater salinity showed significantly declining trends over the 35 years sampling period. Groundwater salinity was similar to the Vertosol electrical conductivity at 240–300 cm depths, suggesting groundwater connectivity to the overlaying soil. Thus, use of sustainability indicators provided a strong association among the various attributes of the landscape. However, it is still a challenge to integrate the various sustainability indicators in a landscape context, integrated over space (spatial and geographical distribution), attributes (quality characteristics) and time (trend).
Reflections on collectively working toward sustainability: indicators for indicators!
Authors: Freebairn D. M. , King C. A.
Published: August 2003

A variety of indicators have been developed and applied by farmers and scientists for the northern cereal belt. A general overview is presented of 'What are we trying to monitor?' followed by some example concepts; erosion hazard, salinity hazard, nutrient balance, production efficiency and participatory learning. These examples illustrate the complexity of indicator application and their dependence on context, purpose and scale. Emphasis is given to providing a rationale for developing indicators that focus on 'soft' system status (e.g. behaviour) as well as 'hard' system status. The propositions put forward are that indicators need to be integrated with the development of improved management systems, and that land managers (and community) as a collective, are key to this process. Some frequently asked questions about indicator development and application are responded to. Some 'Indicators for Indicators' that we have found useful in aiding indicator development, particularly in participatory fora are presented.
Development of soil-landscape and vegetation indicators for managing waterlogged and saline catchments
Authors: Fitzpatrick R. W. , Cox J. W. , Munday B. , Bourne J. F.
Published: August 2003

The objectives of this study were to develop a systematic approach to identify important soil morphological and vegetation field indicators to better target land management in degraded landscapes in a specific region. The authors were able to link the soil-landscape features to the main soil and water processes operating within the landscape. This information was used to develop a set of field indicators (e.g. soil colour) within a user-friendly soil classification key that is linked to land use options to form the basis of a manual. It was shown that information written in this format helped farmers and regional advisers to identify options for remediation of waterlogged and saline areas and to improve planning at property and catchment scales. The authors identified a series of steps to be taken in producing the manual. Steps 1–5 describe the soil layers and construct them in toposequences, which are then used to map soil types in key surrounding areas. Steps 6–9 involve the local community in developing the manual.The paper provides an account of how manuals have been produced for 2 badly degraded areas in southern Australia (Mount Lofty Ranges, South Australia; and western Victoria) and promotes the methodologies for other regions. Descriptive soil information is pictorially integrated along toposequences and applied to identify key soil features. Complex scientific processes and terminology are more simply communicated to local groups using coloured cross-sectional diagrams and photographs of soil and vegetation to overcome some of the perceived barriers to adoption of best management practices. We consider the approach should have generic application.
Soil and catchment health indicators of sustainability: case studies from southern Australia and possibilities for the northern grains region of Australia
Authors: Schwenke G. D. , Reuter D. J. , Fitzpatrick R. W. , Walker J. , O'Callaghan P.
Published: August 2003

During the last decade, a range of indicators has been advocated for assessing soil, farm and catchment health. This paper assembles some recent experiences of the authors in developing and using indicators from paddock to national scales. Indicators are merely a subset of the attributes that are used to quantify aspects of catchment or farm health. Their selection and use in the past has led to criticism of indicators, but, given an explicit approach, most of the criticisms can be overcome. Reliable indicators provide positive and negative signals about the current status of natural resources and how these properties have changed over time. They are used both to identify potential risks and to confirm that current farming practices and systems of land use are effective in maintaining the resource base or economic status. They should be precursors for change and future on-ground investments when problems are observed or identified.A structured approach is needed to ensure indicators are selected and used efficiently. This approach involves: deciding local issues and selecting the most appropriate indicators to reflect those issues; interpreting both positive and negative signals from the monitoring process; taking appropriate action to resolve problems; and, using indicators to monitor the outcomes from the action taken.Finally, we have drawn on these and other experiences to compile a list of indicators that may be used to address sustainability issues associated with farm productivity, soil health and catchment health identified in recent strategic plans developed for the northern grains region of Australia, the focus of this special journal issue.
What is the value of a sustainability indicator? Economic issues in monitoring and management for sustainability
Authors: Pannell D. J.
Published: August 2003

Many factors influence the value to a farmer of monitoring a sustainability indicator. Based on an economic model, a survey of farmers and data on actual farmer monitoring of piezometers, a number of important insights are obtained, including the ones listed below. The value of monitoring indicators will vary by issue, by indicator, by region and by farm. In many cases, the value of continuing to monitor would fall over time as knowledge and understanding increase. For this reason, even successful programs to promote monitoring by farmers may have a limited life expectancy. If monitoring an indicator is to be valuable to a farmer, the indicator must be related to management options which make a difference in achieving the farmer's objectives. However, if the achievement of objectives is very sensitive to management choices, the optimal choice may be so obvious that there is little value in collecting further information about it. The greater the current level of uncertainty about a variable, the greater is the value of monitoring that variable, provided that monitoring does lead to reductions in uncertainty. The greater the degree of uncertainty about the consequences of different management strategies, the lower will be the value of a related indicator. It is not possible to conclude that monitoring indicators is, in general, a good thing.
Evaluation of calcium and canola oil in the diet of feedlot steers
Authors: Oddy V. H. , Bird S. H. , Walker L. G.
Published: August 2003

An experiment was conducted to determine whether the addition of 5.6% canola oil to a barley-based feedlot ration would improve the efficiency of conversion of feed into weight gain and increase the deposition of intramuscular fat. A second aim was to determine what further benefits might accrue from the addition of calcium ions to the rumen.Five groups of 30 steers representing 4 breed crosses were fed in a feedlot for 122 days. The control diet was a standard barley-based ration containing 1.6% calcium carbonate. In a second diet (calcium), calcium carbonate was replaced with 1.2% calcium hydroxide to increase the availability of calcium ions in the rumen. In a third diet (oil), 5.3% canola oil replaced a corresponding weight of barley. The fourth diet comprised oil + calcium and in the fifth, the same weight of oil protected against rumen fermentation was given as Rumentek, replacing 19.5% barley.There was no significant benefit in feed conversion or carcass composition to the substitution of oil for barley in the ration. Supplementary calcium hydroxide reduced the intake of the control diet with little reduction in growth rate. No benefits were observed from the provision of calcium ions in the rumen with either the control or oil diets. The Rumentek diet conferred no benefits in growth rate or feed conversion efficiency, but substantially increased the proportion of unsaturated to saturated long-chain fatty acids in subcutaneous fat, chiefly as polyunsaturates.
The effects of ploidy and seed mass on the emergence and early vigour of perennial ryegrass (Lolium perenne L.) cultivars
Authors: Smith K. F. , McFarlane N. M. , Croft V. M. , Trigg P. J. , Kearney G. A.
Published: August 2003

Genetic variation for seed mass and components of early vigour were measured on 120 seedlings of each of 18 diploid and 27 tetraploid perennial ryegrass (Lolium perenne L.) cultivars. Seeds of tetraploid cultivars were on average heavier (3.8 mg) than seed of diploid cultivars (2.4 mg). However, there was variation for mean seed mass both within and between ploidy classes and within cultivars. The components of early vigour measured on each of the seedlings were: date of emergence, leaf appearance rate, seedling height (10 days after germination), leaf length and width and dry matter at 33 days after emergence. Mean seed mass of a cultivar was significantly (P<0.05) positively correlated with seedling height, leaf length, leaf width, shoot length and shoot mass. Individual seed mass within a cultivar was significantly associated with all components of early vigour, except the date of emergence of the second true leaf. There was no difference in the rate of emergence of tetraploid and diploid cultivars, although tetraploid cultivars tended to have longer and wider leaves, greater seedling lengths and fewer leaves and tillers than diploid cultivars. There was also evidence of genetic variation for seedling vigour components in perennial ryegrass after seed mass and ploidy effects had been removed during analysis. These data suggest that seed mass has a large positive effect on early vigour of both diploid and tetraploid cultivars of perennial ryegrass and that, in the absence of any specific knowledge of the early vigour characteristics of a given cultivar, seed mass could be used as a surrogate when choosing between cultivars with similar adaptation and performance.
Nitrogen fertiliser use on rain-fed pasture in the Mt Lofty Ranges, SouthAustralia. 2. Responses of perennial grasses, Tama ryegrass, andsod-sown oats to nitrogen fertiliser and cutting frequency
Authors: Elliott D. E. , Abbott R. J.
Published: August 2003

Two series of experiments were conducted in the Mt Lofty Ranges, South Australia, to examine, in a grass–subterranean clover pasture, the contribution of the companion grass to herbage mass and the responsiveness to the application of nitrogen (N) fertiliser. The first study examined the responsiveness, to a single rate of N, of grass–clover pastures containing either Tama ryegrass, sod-sown oats or 1 of 4 perennial grasses, viz. Victorian perennial ryegrass, Demeter fescue, Currie cocksfoot or Australian phalaris. These were compared in 2 experiments, under 3��different cutting frequencies at 3 periods during the growing season. In the other study, consisting of 12�experiments, the response to increasing rate of N fertiliser application of sod-sown oats or the existing pasture were compared over a 3-month period following N fertiliser application in autumn.In autumn and winter, all pastures responded significantly to N fertiliser, whereas in spring, the proportion of clover in each pasture and its growth determined whether or not there was a response to N fertiliser. Clover composition of pastures declined with N application, but clover was not eliminated from swards by application of 210 kg N/ha a year. In both series of experiments, pastures that established well with a high density of sod-sown oats out-yielded all other pastures in autumn and winter, whether the swards were unfertilised or received regular N fertiliser applications. In late winter, pastures sod-sown with Tama ryegrass yielded as well as the pasture sod-sown with oats, and enhanced spring growth significantly compared with perennial ryegrass. However, spring production of Tama ryegrass was poorer than that of perennial ryegrass, and overall no increase in annual production occurred. Of the perennial grasses, the highest yielding when N fertiliser was applied were Currie cocksfoot and perennial ryegrass (yielding in autumn), phalaris (winter), and perennial ryegrass and Demeter fescue (spring). Increased cutting frequency depressed the herbage mass response to N fertiliser following the initial application, but increased herbage N concentration of all pastures and also increased the final clover composition of N-fertilised pasture of 4�pasture types.
A single recessive gene confers effective resistance to powdery mildew of field pea grown in northern New South Wales
Authors: Liu S. M. , O'Brien L. , Moore S. G.
Published: August 2003

Reactions to powdery mildew (Erysiphe pisi Syd.) of a range of varieties, advanced lines and pea germplasm from the Australian Temperate Field Crops Collection (ATFCC) were evaluated under field conditions at Narrabri, New South Wales. Thirteen resistant genotypes, including 3 M257 sister lines [M257-2-1 (Mukta), M257-3-6 and M257-5-1], Glenroy, Kiley and PSI 11 from Australian breeding programs, and LE 25 (ATC 1275), ATC 649, ATC 767, ATC 823, ATC 1036, ATC 1121 and ATC 1181 from the ATFCC, along with 8 susceptible lines Dinkum, Bohatyr, Jupiter, Greenfeast, Solara, P441-6, Trapper and Cressy Blue, were used to make resistant × resistant, resistant × susceptible and susceptible × susceptible combinations to examine the inheritance of resistance. Parental lines and F1 and F2 populations were evaluated in the field under natural disease epiphytotics at the Plant Breeding Institute, Narrabri, during the winters of 1996 and 1997. In 1996, resistant and susceptible F2 plants were selected from 5 crosses, and further examined as F3 families in 1997. No fully resistant line was identified among the parents. F1 reactions indicated that resistance was governed by recessive genes and there were no maternal effects. Segregation patterns in the F2 and F3 generations supported the hypothesis of resistance in the genotypes M257-5-1, Glenroy, Kiley, ATC 649 and ATC 1121 being conferred by the same single recessive gene.
Further development of a low-cost release method for sterile Queensland fruit fly Bactrocera tryoni (Froggatt) in rural New South Wales
Authors: Dominiak B. C. , McLeod L. J. , Landon R.
Published: August 2003

Sterile Queensland fruit fly (QFF) Bactrocera tryoni (Froggatt) were released using a pupal-release technique in part of Wagga Wagga. Between August 1997 and May 1998, sterile flies were released using initially sand and later vermiculite mediums in the bed technique. A total of 234.16 million pupae were delivered, with an overall emergence rate of 41.4% and male recapture rate of 0.0365% based on emerged flies. A male recapture rate of 0.0141% was calculated from the male pupae deployed, not corrected for emergence. Released sterile flies were recaptured up to 74 days after release. Of the 16 563 males recaptured, 99.3% of sterile flies were trapped within 1�km of release sites. The CLIMEX model was used to rank the climate at Wagga Wagga to better understand emergence and recapture rates during this and earlier programs. CLIMEX indicated that the 1997–98 year was hotter and drier than both the 2 previous years and the long-term average. The Meats daily survival rate decrement formula was also used to compare quality of sterile flies. Results from previous suppression programs were compared using these parameters. In winter 1998 at Junee, pupae were deployed in foam eskies where emergence varied from 0 to 29%, with CLIMEX Cold Stress at an average of 481. Emergence occurred over a 4-week period. In the 1998–99 summer at Lake Cargelligo, sterile flies were deployed using the pupal-release technique. Foam containers replaced the metal trays from the previous season to afford better insulation from the heat. The average emergence rate was 64% for the program. A male recapture rate of 0.071% was calculated from the 9.12 million pupae deployed or 0.11% from the estimated emerged males. An overflooding ratio of 3.2 was achieved for the season, with some apparent suppression of wild fly populations. The last recaptured sterile fly was trapped 77 days after the final release. CLIMEX, with and without irrigation, was used to assess the suitability of Lake Cargelligo and surrounding rural areas for QFF survival.
Release of sterile Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), at Sydney, Australia
Authors: Dominiak B. C. , Westcott A. E. , Barchia I. M.
Published: August 2003

Four releases of sterile Queensland fruit flies were used in Sydney to assess their flight and distribution characteristics. Flies were detected within 400 m of the release site but did not reach the 5 km trapping array. The distribution was more pronounced towards the north-east and it may have been linked with strong wind prevailing in that direction. CLIMEX was used to indicate that the distribution was not limited by adverse weather. The distribution tended to agree with the formula predicted by Meats (1998). Flies marked with orange dye resulted in the highest recapture rate compared with pink, green and blue dyes. The possible reduction in quarantine radius, following a declared outbreak, is discussed.
Phytotoxicity of aluminium to wheat plants in high-pH solutions
Authors: Ma G. , Rengasamy P. , Rathjen A. J.
Published: August 2003

Phytotoxicity of aluminium in acid soils is well known. At pH ≥6.3, aluminate [Al(OH)4–] is the principal hydroxo-aluminium species in soil solutions; however, its phytotoxicity has not received much attention. Sodic subsoils in Australia are generally alkaline and have pH above 9. During our survey of 8 subsoils in South Australia, we found aluminate ions at concentrations greater than 0.8 mg/L (29.7 μmol/L of aluminium) in soil solutions when pH was greater than 9, with corresponding high uptake of aluminium by wheat plants. We studied the phytotoxicity of aluminium to wheat plants in solution culture by maintaining the pH of alkaline solutions at 9.2.Relative root lengths of wheat plants, compared with those in reverse-osmosis deionised water, were significantly reduced in alkaline solutions and CO2-free air indicated toxicity of hydroxy, carbonate and bicarbonate ions. Further reduction of root lengths due to aluminate toxicity was also evident. Relative root lengths of wheat plants, when comparing between +aluminium and –aluminium treatments, were reduced up to 50% in alkaline solutions containing as low as 1 mg/L of aluminium. Aluminium accumulated mainly in the roots, thereby reducing their growth. In bicarbonate solutions, aluminium toxicity under alkaline pH was highly significant (P<0.001). However, at the same level of added aluminium in carbonate solutions, relative root length was not reduced. This study concludes that when aluminium species are present at a concentration of about 1 mg/L in soil solutions with pH greater than 9, the growth of wheat plants could be significantly affected.
Legume groundcovers have mixed effects on growth and yield ofMacadamia integrifolia
Authors: Firth D. J. , Whalley R. D. B. , Johns G. G.
Published: August 2003

The effects of Lotus pedunculatus (cv. Grasslands Maku) and Arachis pintoi (cv. Amarillo) groundcovers on growth and yield of 1-, 4- and 14-year-old macadamia orchards were investigated over 5 years near Lismore in northern New South Wales. Bare control plots were used at all sites, along with an unmown groundcover in the oldest orchard. Vegetative growth was assessed in terms of shoot extension, trunk diameter and canopy volume. The groundcovers had the greatest effect on vegetative growth of the trees when they were established into an existing sward, followed by the 4-year-old trees, and then the 14-year-old trees. Yields were collected from the 4- and 14-year-old trees and were generally similar under bare soil or groundcovers, with smaller or similar canopy volumes. Nut quality was not consistently affected by the groundcovers, whereas nut-drop was delayed. Acceptable yields can be obtained in macadamias with groundcovers, with potential benefits in terms of soil structure, fertility and stability. Mown and unmown plots have similar productivity.
A survey of dairy farmers' practices and attitudes towards some aspects of arable-land management in the Darling Downs and South Burnett regions of Queensland
Authors: Chataway R. G. , Doogan V. J. , Strong W. M.
Published: August 2003

The Darling Downs and Southern Inland Burnett are important geographical subregions of the Queensland dairy industry. The system of dairy farming in these subregions is unique in Australia in that it is based on grazed annual forage crops rather than pastures. When these soils were first cultivated up to 110 years ago they were inherently fertile. However, erosion and fertility decline has reduced their productive capacity and there is a need for the adoption of farming practices that are less exploitative. In February 1997, a survey was conducted to determine dairy farmers' practices and attitudes toward management strategies that were being recommended to grain farmers in the subtropical cereal belt for sustaining the soil resource base. These strategies included greater use of ley pastures, opportunistic double-cropping, zero-till planting and higher fertiliser inputs. We found that dairy farmers were generally familiar with and understanding of the potential benefits of these approaches to their farming enterprises. However, farmers raised a number of issues that need consideration in the transfer of these practices to dairy forage production. These included concerns that an increased emphasis on pastures would result in lower and less-reliable forage production; that double-cropping is practiced more out of necessity than in the belief it is a better way to farm; that zero tillage may not be suitable on clay soils that have been trampled by cattle and that farmers rely primarily on their own observations of crop performance to determine fertiliser use. These findings have particular implications for research and extension activities conducted with dairy farmers and are also relevant to work conducted with other cropping enterprises that incorporate grazing animals in their farming program.
Alternative crop production strategies for rice-wheat cropping systems in the Indo-Gangetic plains of India
Authors: Pal M. S.
Published: August 2003

Field experiments were carried out in the Indo-Gangetic plains of India during 1997–98, 1998–99 and 1999–2000 with the objective to identify alternative crop sequences that are more productive as well as remunerative than the rice–wheat cropping system. The results indicated that the highest mean sunflower seed yield was obtained in the soybean–sunflower rotation followed by the rice–sunflower rotation and the lowest in the maize–mustard–sunflower crop rotation. Similarly, the sesbania–toria–sunflower rotation had the highest biological yield followed by the soybean–sunflower and urd–toria–sunflower rotations. The mean highest harvest index was found in the cowpea–toria–sunflower rotation (35.1%) followed by the urd–toria–sunflower (33.2%) and rice–sunflower (32.7%) rotations. A significantly high oil content in sunflower seeds was observed in both the soybean–sunflower and sesbania–toria–sunflower rotations that was similar to that in the urd–toria–sunflower and cowpea–toria–sunflower rotations. The maize–potato–sunflower, maize–mustard–sunflower, cowpea–toria– sunflower and rice–sunflower rotations had significantly higher sunflower seed yield equivalents (201, 17, 15 and 4% higher, respectively) than the rice–wheat rotation. Similarly, the maize–potato–sunflower rotation produced the highest net income followed by cowpea–toria–sunflower, rice–sunflower and maize–mustard–sunflower, that was 351, 37, 14 and 4%, respectively, higher than the net income of the rice–wheat rotation. The benefit : cost ratio was also observed to be significantly highest in the maize–potato–sunflower rotation (1.60). After 3 years of field experimentation, soil organic carbon, available nitrogen, phosphorus and potassium were observed to be highest in the urd–toria–sunflower, soybean–sunflower, cowpea–toria–sunflower and soybean–sunflower rotations, respectively. The mean value of total available nutrients was greater in soybean–sunflower than rice–wheat rotation.It can be concluded that the cowpea–toria–sunflower, soybean–sunflower and rice–sunflower crop rotations may be preferred for greater sustainability over the rice–wheat system not only in the Indo-Gangetic plains of India but also in the whole of Asia, and these findings may be a very useful reference for future research on Australian crop diversification.
The effect of plantation age on the yield of some mint (Mentha spp.) varieties
Authors: Ozel A.
Published: August 2003

This study was conducted to determine the productivity of aging plantation of some mint varieties (Mentha spp.) in Sanliurfa in the south-east of Turkey. The trial was carried out between 1994 and 1998 (5 years) and was designed as a split-plot study, with 3 replications. The M. piperita L. (Mitcham), M. piperita L. (Prilubskaja) and M. spicata (Urfa Local) varieties were used as plant material. Results obtained showed that the fresh herb yield (t/ha), dry herb yield (t/ha), dry leaf yield (t/ha), essential oil yield (L/ha) and essential oil content (%) were significantly affected by the plantation age in all varieties investigated. The yields of fresh herbs, dry herbs, dry leaves and essential oils decreased dramatically in the fourth and fifth years of harvest from the plantation as only 1 harvest could be achieved during these years.
Effect of legume-managed fallow on weeds and soil nitrogen in following maize (Zea mays L.) and wheat (Triticum aestivum L.) crops in the Rift Valley highlands of Kenya
Authors: Cheruiyot E. K. , Mumera L. M. , Nakhone L. N. , Mwonga S. M.
Published: August 2003

The use of legume crops as alternatives to a fallow in wheat–maize rotations in the Rift Valley of Kenya may suppress weeds and add nitrogen to the system. A field study was set up in the Njoro and Rongai regions to evaluate the effect of managing the traditional fallow with chickpea (Cicer arietinum L.), field bean (Phaseolus vulgaris L.), soybean [Glycine max (L.) Merril], field pea (Pisum sativum L.) and dolichos [Lablab purpureus (L) Sweet] on the following wheat and maize crops. The objectives of this study were to assess the impact of improved fallow on weed control, soil nitrogen and performance of the following cereals in a bid to improve their yields. The legumes, along with wheat and maize, were grown as fallow-management treatments during the short-rains season, and their residues were incorporated into the soil before sowing the test cereal in the long-rains season. Weed biomass and species diversity reduced by 35–92% and 25–58% at Njoro, and 10–100% and 83–100% at Rongai, respectively, in the succeeding cereal against preceding traditional fallow. The perennial weeds, which included Digitaria scalarum, Pennisetum clandestinum and Conyza sp., were substantially reduced in the managed fallow. Legume-managed fallow significantly improved soil nitrogen status and the yield of the following cereals. Grain yield in managed fallow increased on average by about 39 and 17% over locations in maize and wheat, respectively. Despite yielding less soil-incorporated residue, the impact of legumes was greater than that of the traditional fallow yielding large amount of organic material. Among the legume species, dolichos showed outstanding positive effect on succeeding cereal crop, probably due to increased soil nitrate levels. Field bean and chickpea have a potential seed advantage, although the latter is susceptible to 100% loss by Helicoverpa armigera. Hence, managing the traditional short-rains fallow with legumes could reduce weed infestation, in addition to improving soil nitrogen for subsequent crops.
Abscisic acid analogue effects on the vase life and leaf crisping of cut Baccara roses
Authors: Pompodakis N. E. , Joyce D. C.
Published: August 2003

The plant growth regulator abscisic acid induces stomatal closure, which can reduce transpiration rate and extend vase life of cut flowers by maintaining a positive water balance. Analytical-reagent grade abscisic acid is, however, expensive. In this work, the effects of 2 potentially inexpensive synthetic analogues of abscisic acid were studied as to their effects on cut Baccara roses. Abscisic acid and its analogues PBI-365 and PBI-429 reduced transpiration and helped to increase fresh weight during the first few days of vase life. However, the reduction in transpiration rate brought about by abscisic acid and the analogues did not alter vase life. Sucrose in the vase solution at concentrations of 2 and 4% increased vase life of cut Baccara roses. However, the highest sucrose concentration (4%) caused leaf crisping, thereby reducing the quality of the flower stems. Abscisic acid and the analogue PBI-365 reduced this phytotoxicity by induction of stomatal closure and reduction of vase solution sucrose flux into the leaves.
Identifying potential approaches to improve the reliability of terminating a lucerne pasture before cropping: a review
Authors: Davies S. L. , Peoples M. B.
Published: August 2003

In the mixed cropping regions of Australia, the perennial fodder legume lucerne (Medicago sativa L.) is being utilised to improve the sustainability of farming systems through improving soil fertility and reducing groundwater recharge. However, the full rotational benefits of lucerne cannot be realised without a reliable approach to terminate the lucerne phase before cropping. Farmer surveys have identified difficulties in successfully removing lucerne before cropping as a significant problem with lucerne-based phase-farming systems. In 1 survey up to 40% of the respondents were not satisfied with the level of lucerne control they were achieving, while in another survey 49% indicated that lucerne removal issues were a constraint to further adoption of lucerne on their farms. Most growers used herbicides to kill lucerne, usually in conjunction with cultivation or grazing. Respondents estimated that herbicides were capable of killing 80% of the lucerne, but most regarded this level of control unsatisfactory. Lucerne removal using herbicides is ineffective when lucerne is able to regenerate from buds in the crown that have not received a lethal herbicide dose. Systemic herbicides such as glyphosate and the auxinic herbicides are predominantly translocated to those parts of the plant with a high demand for photosynthate, often the apical meristems. Hence, effective control of lucerne can only be achieved through targeted application of systemic herbicides to lucerne plants that are actively translocating photosynthate to the crown and taproots. Evidence presented in this review suggests that this is most likely to occur when the storage reserves in the crown and taproot are being replenished several weeks after defoliation. The importance of timing of removal and the potential for intercropping are also discussed.
Water extraction by sugarcane on soils of the Ord Irrigation Area
Authors: Plunkett G. M. , Muchow R. C.
Published: August 2003

Sugarcane is a new commercial crop in the Ord River Irrigation Area and irrigation management strategies are required for profitable production with minimal environmental consequences such as rising ground water. Knowledge of soil water properties and sugarcane water requirements is a necessary prerequisite for best-practice irrigation. Accordingly, soil water measurements were taken to quantify the amount and depth pattern of water extraction by sugarcane on the Ivanhoe Plain in the Ord River Irrigation Area.The drained upper limit and crop lower limit of extraction were measured on 4 soil types. The amount of soil water available to the sugarcane plant varied between soil types, ranging from 226 to 167 mm in a 2.0 m profile. Sugarcane extracted water down to 1.8 m at the Central and Northern Ivanhoe sites, down to 1.6 m at the Southern Ivanhoe site, but only down to 1.0 m at the Aquitaine site. The pattern of water use over time was determined at 2�sites and showed higher crop water use before the wet season and much lower crop water use after the wet season. There was considerable reduction in the ratio of crop water use to Class A pan evaporation after the wet season. Lower irrigation frequency after the wet season on maturing crops will improve irrigation efficiency and reduce impacts on the environment.This knowledge of the different soil water properties of the 4 soil types can be used with crop growth models to develop recommendations for best-practice irrigation management of sugarcane across the Ord River Irrigation Area. These recommendations need to account for the high soil water extraction capability of sugarcane growing in this environment.
Sheep are potential vectors for the spread of canola (Brassica napus) seed
Authors: Stanton R. , Pratley J. , Hudson D.
Published: August 2003

Sheep and other livestock are capable of ingesting seeds from weeds and desirable pasture species and excreting a percentage of viable seeds. As livestock are used to graze stubble paddocks after harvest, any crop seed shed before harvest or spilt during the harvesting process could also be ingested and subsequently excreted as viable seed. Knowledge of the rate of passage and viability of crop seed ingested by livestock is critical for good farm hygiene so that seeds are not inadvertently spread from the source paddock. Merino wethers were placed on a diet containing whole canola seed (10% total dry matter), and faeces were collected while canola was in the diet and for a further 6 days after canola was removed from the diet. Seed was found to pass through the wethers in less than 1�day, and reached a constant level after 2 days. When canola seed was removed from the diet, the majority of seed was passed during the first 2 days, but seed was excreted for up to 5 days. Seed germinability was reduced after 1�day, and further still after 2 days, but did not significantly decrease after this. While sheep are capable of excreting germinable canola seeds for up to 5 days after they were last included in the diet, use of a 7–10-day holding period will ensure that canola is not inadvertently spread beyond the grazed stubble paddock.
Trials on variants of the Sterile Insect Technique (SIT) for suppression of populations of the Queensland fruit fly in small towns neighbouring a quarantine (exclusion) zone
Authors: Meats A. W. , Duthie R. , Clift A. D. , Dominiak B. C.
Published: August 2003

Seven small unquarantined towns in the central western district of New South Wales were used to compare variants of the sterile insect technique with respect to their suitability for suppression of populations of the Queensland fruit fly, Bactrocera tryoni (Froggatt). Two towns were treated with weekly releases of immature sterile flies at rates varying from 48 000 to 115 000 sterile males per km2. Evidence for suppression was poor (from comparison with 2� untreated towns) and the ratio of sterile to wild flies caught in monitoring traps never exceeded 80 : 1 in the last 4�weeks of any season or 40 : 1 during other parts of any season. However, the recapture rates of the sterile flies and estimates of their survival rates were often as good as the best that have been reported previously. Two other towns were treated with weekly releases of mature flies at rates of 5000–12 000 sterile males per km2. The recapture rates and estimates of survival rates of flies released when mature were unexpectedly low and the ratios of sterile to wild flies were often less than 1 : 1 and never exceeded 12 : 1. The results are discussed in terms of the relatively harsh climate of these towns (located in a region of average annual rainfall of 450–600 mm) and lack of quarantine.
Incipient founder populations of Mediterranean and Queensland fruitflies in Australia: the relation of trap catch to infestation radius andmodels for quarantine radius
Authors: Meats A. W. , Clift A. D. , Robson M. K.
Published: August 2003

We examined data from 75 infestations of the Mediterranean fruit fly (Medfly) and 286 of the Queensland fruit fly (Qfly) that have occurred in quarantined and normally fly-free zones in Australia from 1974 to 2000. The radius of occurrence of both adult male flies and infested fruit was almost always less than 1 km. The rare cases where there was an isolated occurrence beyond 1 km of an epicentre were most likely due to (and can be treated as) separate introductions. Our analysis shows that effective quarantine radii for suspension of fly-free status should be related to the number of flies trapped around the epicentre and the density of the trap array (if the appropriate code of practice is applied). Most detections of fruit flies involve the trapping of very few flies and 18% of Medfly infestations and 71% of Qfly infestations that are detected are not classified as outbreaks and are left to die out without any treatment. For each species, we have used 3 alternative methods to calculate confidence limits for infestation radii. The upper limits could also serve as quarantine radii. These limits increase with the rate of trapping of male flies and have a theoretical probability of 3/100 000 (i.e. probit 9) of being exceeded. The quarantine radii for most declared outbreaks, when calculated with any of our methods, would be small because the number of flies detected is usually only just above the threshold for such a declaration. If our methods were used for beneficial species or for re-introductions of endangered species, the lower confidence limits could be used to calculate the size of inoculum required for a high probability of initial establishment.