Developments in adaptation to salinity at the crop level

The domestication of halophytic species and their use in agriculture has been tested by several authors to replace or supplement the vegetation of saline rangelands. In adopting plants that were originally gathered in nature for controlled cultivation under farmers’ care, the selection favored plant species that were fast-growing, performed well in the absence of other competition and disturbed soil, did not have extensive defense traits, such as thorns or toxins, and produced many seeds. Most of the saline agriculture crops have only recently been entered into breeding and selection programs, although several studies have been done on what people can consider landraces, many of the traits associated with elite varieties have not been systematically studied yet

Application of Distributed Wireless Chloride Sensors to Environmental Monitoring: Initial Results

Over the next 30 years, it is anticipated that the world will need to source 70% more food to provide for the growing population, and it is likely that a significant amount of this will have to come from irrigated land. However, the quality of irrigation water is also important, and measuring the quality of this water will allow management decisions to be made. Soil salinity is an important parameter in crop yield, and in this paper, we describe a chloride sensor system based on a low-cost robust screen-printed chloride ion sensor, suitable for use in distributed sensor networks. Previously, this sensor has been used in controlled laboratory-based experiments, but here we provide evidence that the sensor will find application outside of the laboratory in field deployments. We report on three experiments using this sensor; one with a soil column, one using a fluvarium, and finally on an experiment in a greenhouse. All these give an insight into the movement of chloride over small distances with high temporal resolution. These initial experiments illustrate that the new sensors are viable and usable with relatively simple electronics, and although subject to ongoing development, they are currently capable of providing new scientific data at high spatial and temporal resolutions. Therefore, we conclude that such chloride sensors, coupled with a distributed wireless network, offer a new paradigm in hydrological monitoring and will enable new applications, such as irrigation using mixtures of potable and brackish water, with significant cost and resource saving

Salt-Tolerant Forages for Irrigated Saline Land in Central Iraq

Salinity is a major problem in the irrigated zones of central and southern Iraq. We investigated biomass production from five salt-tolerant forage species, represented by 15 introduced accessions and 3 local accessions, during two successive summer growing seasons. Species included pearl millet (Pennisetum glaucum), sorghum (Sorghum bicolour), guar (Cluster bean; Cyamopsis tetragonoloba), cowpea (Vigna unguiculata) and sesbania (Sesbania aculeata and S. sesban). The research site was located in the Al-Dujaila irrigation project area in Wasit. The soil had a silty clay texture with moderate salinity (ECe 10-20 dS/m). The site was irrigated with water (ECw 1.1 dS/m) from the Tigris River on a 3 to 8 day basis. We hypothesised that there would be variation in biomass production, salt accumulation and crude protein both between and within species. In addition, we thought that the legumes would be less productive than grasses as they tend to be more sensitive to salinity. Over 2 experimental seasons, the plants produced an average shoot dry mass of 12.1 t/ha with a range for accessions of 3 to 35 t/ha. There was significant variation both within and between species, supporting the first hypothesis. None of the plants accumulated excessive salt (ash \u3c 12% DM); crude protein was variable (6 to 12%), but higher in two legumes – cowpea and sesbania. Furthermore, there was no evidence that grasses were more productive than legumes, with sesbania and cowpea achieving the highest mean biomass production across the years. We conclude that moderately saline irrigated areas of Iraq can sustain high levels of biomass production for livestock although protein may be limited

Profitable and Sustainable Grazing Systems for Livestock Producers with Saline Land in Southern Australia

Dryland salinity affects over 2.5 M ha in Australia, mostly in southern states and is expanding at 3-5% per year (NLWRA, 2001). The prognosis is for considerable expansion of the area affected by salinity and waterlogging (1217 M ha at equilibrium), because groundwater levels continue to rise and only small-scale land management programmes have been implemented. In addition, many waterways are increasingly saline, especially in the Murray Darling Basin and in Western Australia (WA). Sustainable Grazing on Saline Land (SGSL) addresses the need to make productive use of saline land and water resources. Its research component operates at 12 sites across WA, South Australia (SA), Victoria and New South Wales (NSW) and consists of coordinated activities that have regional relevance and contribute nationally. The programme seeks to develop and demonstrate profitable and sustainable grazing systems on saline land that have positive environmental and social impacts. Whilst there are different priority research issues at each site, data collection is governed by common measurement protocols for salt and water movement, biodiversity, and pasture and animal performance in order to make comparisons and data sharing across sites practical

Profitable and Sustainable Grazing Systems for Livestock Producers with Saline Land in Southern Australia

Dryland salinity affects over 2.5 M ha in Australia, mostly in southern states and is expanding at 3-5% per year (NLWRA, 2001). The prognosis is for considerable expansion of the area affected by salinity and waterlogging (12–17 M ha at equilibrium), because groundwater levels continue to rise and only small-scale land management programmes have been implemented. In addition, many waterways are increasingly saline, especially in the Murray Darling Basin and in Western Australia (WA). Sustainable Grazing on Saline Land (SGSL) addresses the need to make productive use of saline land and water resources. Its research component operates at 12 sites across WA, South Australia (SA), Victoria and New South Wales (NSW) and consists of coordinated activities that have regional relevance and contribute nationally. The programme seeks to develop and demonstrate profitable and sustainable grazing systems on saline land that have positive environmental and social impacts. Whilst there are different priority research issues at each site, data collection is governed by common measurement protocols for salt and water movement, biodiversity, and pasture and animal performance in order to make comparisons and data sharing across sites practical

Subsoil contraints and their management: Overview from five years of R&D

Subsoil constraints cost the grains industry more than $1.6b in lost production each year. Diagnosing and mapping subsoil constraints (SSC) was achieved at a shire scale using the DPIRD soils database and historic surveys

Inland dry season saline intrusion in the Vietnamese Mekong River Delta is driving the identification and implementation of alternative crops to rice

CONTEXT: Inland saline intrusion is occurring during the dry season in the Mekong River Delta (MRD), Vietnam. Rising sea levels, tidal fluctuations, drought, and changes to upstream flow contribute to extensive salinisation of rice producing areas of the MRD, leading to substantial rice crop losses. OBJECTIVE: The identification, evaluation and implementation of alternative crop and soil management solutions are required to complement on-going rice production in the region. METHODS: A review of scientific and grey literature was conducted regarding the nature and extent of salinisation in the MRD and the adoption and management of alternative crops to rice. RESULTS: Familiar crops in Vietnam (e.g., maize, soybean), as well as novel crops to the MRD (e.g., quinoa, cowpea) were explored as potential options to replace dry season rice. Management options including surface soil mulches and plastic coverings help maintain soil moisture and reduce salinity damage to plants, and the use of drainage and seed preparation techniques can improve plant establishment and yield. Factors contributing to the success of alternative crops include salt tolerance, timing and efficiency of water use, ability to grow in the dry growing season, tolerance to pests and diseases, labour intensiveness and the crops' marketability. SIGNIFICANCE: The identification of suitable alternative crops to replace dry season rice in saline affected areas of the MRD, combined with management practices like mulching and soil moisture monitoring, could provide farmers with income opportunities to offset rice losses. Documenting the factors contributing to successful crop diversification can assist with decision-making and support initiatives among farmers, agribusiness, and government agencies

Sheep Updates 2007 - part 3

This session covers seven papers from different authors: PROFITABILITY 1. Benchmarking demonstrates both the potential and realised productivity gains in the sheep and wool industry, Andrew Ritchie, Edward Riggall and James Hall, ICON Agriculture, Darkan 2. Improving sheep genetics will increase farm profitability, Gus Rose, Johan Greeff Department of Agriculture and Food Western Australia, John Young Farming Systems Analysis Service, WA 3. Meat, Merinos and making money in WA Pastoral Zone, M. Alchin, M. Young and T. Johnson, Department of Agriculture and Food Western Australia, GRAZING 4. Nitrogen - farmers\u27 friend or foe? John Lucy and Martin Staines, Department of Agriculture and Food Western Australia 5. Drought proofing grazing systems - a case study from Binnu 2006/7, Tim Wiley & Rob Grima, Department of Agriculture & Food Western Australia 6. Minimising \u27Esperance Storm\u27 livestock losses, Sandra Prosser and Matt Ryan, Department of Agriculture and Food Western Australia 7. Sub-tropical grasses in WA - what is their potential? Geoff Moore, Tony Albertsen, Department of Agriculture & Food Western Australia, Phil Barrett-Lennard, Evergreen Farming, George Woolston, John Titterington, Department of Agriculture and Food Western Australia, Sarah Knight, Irwin-Mingenew Group, Brianna Peake, Liebe Group, Buntine, W

Saltland Capability Assessment: Targeting Plants to Landscapes to Increase Profitability

Saltland varies in its capacity for productive and profitable use. For example, in the Central Wheatbelt of Western Australia it ranges from being highly productive and profitable ($40-80/ha/yr) to being of negligible productivity and profitability. To reduce the spread and impact of salinity, perennial plants need to be planted on saltland to lower the watertable, but annual under-storey plants are essential to increase productivity and profitability through increased grazing opportunities. Clear guidelines are required so that interventions on saltland match the optimal combinations of plant species to the landscapes of different capability. Research conducted at four trial sites in the medium rainfall (350-550 mm/yr) zone of Western Australia, with river saltbush, small-leaf bluebush, samphire, Rhodes grass, saltwater couch, puccinellia, tall wheat grass and lucerne, led to the development of a saltland capability assessment tool based on the following assessments; 1) level of salinity in the subsoil (25–50 cm depth), 2) depth to the watertable, and 3) presence of plant “indicator species.” Results from the field trials combined with economic analysis suggested that profitability of the grazing system will be highest if plantings are confined to land with average ECe values less than 8 dS/m and watertables in summer deeper than ~1 m. The featured saltland capability assessment tool is a first step. However, the decision support tool needs to be validated across a wider range of saline sites and expanded to incorporate a wider range of plants. Farmer participation and validation is an essential component of this process; this participation will be continued through the Future Farm Industries CRC “Saltland Knowledge Exchange” and “SALTCAP” Projects

Mechanism of Short Term Fe(III) Reduction by Roots : Evidence against the Role of Secreted Reductants

The hypothesized role of secreted reducing compounds in Fe(III) reduction has been examined with Fe-deficient peanuts (Arachis hypogaea L. cv A124B). Experiments involved the exposure of roots to (a) different gas mixtures, (b) carbonyl cyanide m-chlorophenylhydrazone (CCCP), and (c) agents which impair membrane integrity. Removing roots from solution and exposing them to air or N(2) for 10 minutes did not result in any accumulation in the free space of compounds capable of increasing rates of Fe(III) reduction when roots were returned to solutions. On the contrary, exposing roots to N(2) decreased rates of Fe(III) reduction. CCCP also decreased rates of Fe(III) reduction. Acetic acid and ethylenediaminetetraacetic acid (disodium salt) (EDTA) impaired the integrity and function of the plasma membranes of roots of Fe-deficient peanuts. That is, in the presence of acetic acid or EDTA, there was an efflux of K(+) from the roots; K(+) ((86)Rb) uptake was also impaired. Acetic acid increased the efflux from the roots of compounds capable of reducing Fe(III). However, both acetic acid and EDTA caused rapid decreases in rates of Fe(III) reduction by the roots. In addition to peanuts, acetic acid also decreased rates of Fe(III) reduction by roots of Fe-deficient sunflowers (Helianthus annuus L. cv Sobrid) but not maize (Zea mays L. cv Garbo). These results suggest that, at least in the short term, the enhanced Fe(III) reduction by roots of Fe-deficient plants is not due to the secretion of reducing compounds