Modeling Irrigated Cropping systems with Special Attention to Rice Wheat Sequences and Rice Bed Planting

The rice-wheat cropping systems of the Indo-Gangetic Plains (IGP) are of immense importance for food security for south Asia. Over the past 40 years the increase in rice and wheat production has kept pace with population growth due to improved varieties, increased inputs, especially fertilisers, and the expansion of irrigation. However yield stagnation, and possibly yield decline, water scarcity, and water and air pollution are major threats to the sustainability of rice-wheat systems and food security. Therefore the design and implementation of alternative production systems with increased resource use efficiency (especially water) and productivity and reduced adverse environmental impact are urgently required. Bed farming, practised for several decades for crops other than rice in Australia, Mexico and elsewhere, was introduced to the rice-wheat regions of the IGP in the mid 1990s. Farmer experience and research have shown that bed farming offers significant advantages for productivity and resource use efficiency for wheat and other non-rice crops. More recently, attention has focused on the possibility of also growing rice on beds in the IGP and Australia, with the associated potential benefits of permanent bed systems including reduced land preparation costs and turn around times, increased cropping flexibility, and increased productivity of “upland” crops grown in rotation with rice due to improved drainage and soil structure and improved rotations. The radical shift from ponded rice culture on the flat (with or without puddling and transplanting) to intermittently flooded bed layouts affects a host of interacting factors influencing productivity and resource use efficiency of both rice and crops grown in rotation with rice. These factors range from weeds to nutrient availability to pests and diseases to water dynamics to stubble management options. The potential benefits and disadvantages of permanent bed systems need to be quantified under a range of agroecological conditions, and optimum layouts and management systems need to be identified to maximise potential gains. The Australian Centre for International Agricultural Research (ACIAR) is funding a major new project LWR2/2000/89 Permanent beds for rice-wheat and alternative cropping systems in north west India and south east Australia. This is a collaborative project between Punjab Agricultural University, CSIRO Land and Water and NSW Agriculture, with additional support from the International Atomic Energy Agency (IAEA/FAO) for the work in India, and additional support for the work in Australia from the Rural Industries Research and Development Corporation (RIRDC) Rice program, the Grains Research and Development Corporation (GRDC) and Coleambally Irrigation Cooperative Ltd and Murray Irrigation Ltd. The major part of the project comprises field comparison of permanent bed and traditional layouts for rice-based cropping systems in Punjab, India and NSW, Australia, with detailed monitoring, in particular focusing on crop growth and development, water and nitrogen dynamics and balances, and options for stubble management. The project also seeks to further develop and refine models for rice-wheat and alternative systems, and apply them to evaluate permanent bed and traditional layouts for a range of agroecological environments, and to identify options for maximizing resource use efficiency and productivity of rice-wheat cropping systems in India, and rice-based cropping systems in Australia. Therefore an early activity in the project vi was a workshop bringing together a small group of international scientists leading in the development and application of crop models including the modelling of crop sequences and twodimensional approaches. The objectives of the workshop were: 1. to review the state of the art in the modelling irrigated cropping systems (crop sequences as opposed to single crops) and bed geometries (as opposed to “flat” layouts) 2. to workshop conceptualizations of the ways forward in modelling crop sequences and bed layouts, and with particular attention to rice-wheat systems 3. to establish a network of contacts working in these areas to share progress and problems in the future

Modeling Irrigated Cropping systems with Special Attention to Rice Wheat Sequences and Rice Bed Planting

The rice-wheat cropping systems of the Indo-Gangetic Plains (IGP) are of immense importance for food security for south Asia. Over the past 40 years the increase in rice and wheat production has kept pace with population growth due to improved varieties, increased inputs, especially fertilisers, and the expansion of irrigation. However yield stagnation, and possibly yield decline, water scarcity, and water and air pollution are major threats to the sustainability of rice-wheat systems and food security. Therefore the design and implementation of alternative production systems with increased resource use efficiency (especially water) and productivity and reduced adverse environmental impact are urgently required. Bed farming, practised for several decades for crops other than rice in Australia, Mexico and elsewhere, was introduced to the rice-wheat regions of the IGP in the mid 1990s. Farmer experience and research have shown that bed farming offers significant advantages for productivity and resource use efficiency for wheat and other non-rice crops. More recently, attention has focused on the possibility of also growing rice on beds in the IGP and Australia, with the associated potential benefits of permanent bed systems including reduced land preparation costs and turn around times, increased cropping flexibility, and increased productivity of “upland” crops grown in rotation with rice due to improved drainage and soil structure and improved rotations. The radical shift from ponded rice culture on the flat (with or without puddling and transplanting) to intermittently flooded bed layouts affects a host of interacting factors influencing productivity and resource use efficiency of both rice and crops grown in rotation with rice. These factors range from weeds to nutrient availability to pests and diseases to water dynamics to stubble management options. The potential benefits and disadvantages of permanent bed systems need to be quantified under a range of agroecological conditions, and optimum layouts and management systems need to be identified to maximise potential gains. The Australian Centre for International Agricultural Research (ACIAR) is funding a major new project LWR2/2000/89 Permanent beds for rice-wheat and alternative cropping systems in north west India and south east Australia. This is a collaborative project between Punjab Agricultural University, CSIRO Land and Water and NSW Agriculture, with additional support from the International Atomic Energy Agency (IAEA/FAO) for the work in India, and additional support for the work in Australia from the Rural Industries Research and Development Corporation (RIRDC) Rice program, the Grains Research and Development Corporation (GRDC) and Coleambally Irrigation Cooperative Ltd and Murray Irrigation Ltd. The major part of the project comprises field comparison of permanent bed and traditional layouts for rice-based cropping systems in Punjab, India and NSW, Australia, with detailed monitoring, in particular focusing on crop growth and development, water and nitrogen dynamics and balances, and options for stubble management. The project also seeks to further develop and refine models for rice-wheat and alternative systems, and apply them to evaluate permanent bed and traditional layouts for a range of agroecological environments, and to identify options for maximizing resource use efficiency and productivity of rice-wheat cropping systems in India, and rice-based cropping systems in Australia. Therefore an early activity in the project vi was a workshop bringing together a small group of international scientists leading in the development and application of crop models including the modelling of crop sequences and twodimensional approaches. The objectives of the workshop were: 1. to review the state of the art in the modelling irrigated cropping systems (crop sequences as opposed to single crops) and bed geometries (as opposed to “flat” layouts) 2. to workshop conceptualizations of the ways forward in modelling crop sequences and bed layouts, and with particular attention to rice-wheat systems 3. to establish a network of contacts working in these areas to share progress and problems in the future

Remotely sensed and modelled pasture biomass, land condition and the potential to improve grazing-management decision tools across the Australian rangelands

This report assesses the potential for expanding on current capacity to monitor land condition using remotely sensed fractional cover products to improve biomass estimation, animal productivity, pasture growth models and grazing decision tools (e.g. safe carrying capacity) across the Australian rangelands. We focus on northern Australia and include relevant research and implementation from southern Australia where appropriate

Potential synergies between existing multilateral environmental agreements in the implementation of Land Use, Land Use Change and Forestry activities

There is potential for synergy between the global environmental conventions on climate change, biodiversity and desertification: changes in land management and land use undertaken to reduce net greenhouse gas emissions can simultaneously deliver positive outcomes for conservation of biodiversity, and mitigation of desertification and land degradation. However, while there can be complementarities between the three environmental goals, there are often tradeoffs. Thus, the challenge lies in developing land use policies that promote optimal environmental outcomes, and in implementing these locally to promote sustainable development. The paper considers synergies and tradeoffs in implementing land use measures to address the objectives of the three global environmental conventions, both from an environmental and economic perspective. The intention is to provide environmental scientists and policy makers with a broad overview of these considerations, and the benefits of addressing the conventions simultaneously.Climate change, LULUCF, Biodiversity, Desertification, Sustainable development.

Climate Change in Queensland's Grazing Lands: II. An Assessment of the Impact on Animal Production From Native Pastures

The 160 million ha of grazing land in Queensland support approximately 10 million beef equivalents (9.8 million cattle and 10.7 million sheep) with treed and cleared native pastures as the major forage source. The complexity of these biophysical systems and their interaction with pasture and stock management, economic and social forces limits our ability to easily calculate the impact of climate change scenarios. We report the application of a systems approach in simulating the flow of plant dry matter and utilisation of forage by animals. Our review of available models highlighted the lack of suitable mechanistic models and the potential role of simple empirical relationships of utilisation and animal production derived from climatic and soil indices. Plausible climate change scenarios were evaluated by using a factorial of rainfall (f 10%) * 3260C temperature increase * doubling CO, in sensitivity studies at property, regional and State scales. Simulation of beef cattle liveweight gain at three locations in the Queensland black speargrass zone showed that a *lo% change in rainfall was magnified to be a f 15% change in animal production (liveweight gain per ha) depending on location, temperature and CO, change. Models of 'safe' carrying capacity were developed from property data and expert opinion. Climate change impacts on 'safe' carrying capacity varied considerably across the State depending on whether moisture, temperature or nutrients were the limiting factors. Without the effect of doubling CO,, warmer temperatures and +lo% changes in rainfall resulted in -35 to +70% changes in 'safe' carrying capacity depending on location. With the effect of doubling CO, included, the changes in 'safe' carrying capacity ranged from -12 to +115% across scenarios and locations. When aggregated to a whole-of-State carrying capacity, the combined effects of warmer temperature, doubling CO, and +lo% changes in rainfall resulted in 'safe' carrying capacity changes of +3 to +45% depending on rainfall scenario and location. A major finding of the sensitivity study was the potential importance of doubling CO, in mitigating or amplifying the effects of warmer temperatures and changes in rainfall. Field studies on the impact of CO, are therefore a high research priority. Keywords: climate change, Queensland, simulation, rangelands, beef production, cattle, carrying capacity, CO,, utilisatio

Adaptive management of Ramsar wetlands

Abstract The Macquarie Marshes are one of Australia’s iconic wetlands, recognised for their international importance, providing habitat for some of the continent’s more important waterbird breeding sites as well as complex and extensive flood-dependent vegetation communities. Part of the area is recognised as a wetland of international importance, under the Ramsar Convention. River regulation has affected their resilience, which may increase with climate change. Counteracting these impacts, the increased amount of environmental flow provided to the wetland through the buy-back and increased wildlife allocation have redressed some of the impacts of river regulation. This project assists in the development of an adaptive management framework for this Ramsar-listed wetland. It brings together current management and available science to provide an informed hierarchy of objectives that incorporates climate change adaptation and assists transparent management. The project adopts a generic approach allowing the framework to be transferred to other wetlands, including Ramsar-listed wetlands, supplied by rivers ranging from highly regulated to free flowing. The integration of management with science allows key indicators to be monitored that will inform management and promote increasingly informed decisions. The project involved a multi-disciplinary team of scientists and managers working on one of the more difficult challenges for Australia, exacerbated by increasing impacts of climate change on flows and inundation patterns

Integrating Knowledge for River Basin Management: Progress in Thailand

Resource /Energy Economics and Policy,

Predicting water quality and ecological responses

Abstract Changes to climate are predicted to have effects on freshwater streams. Stream flows are likely to change, with implications for freshwater ecosystems and water quality. Other stressors such as population growth, community preferences and management policies can be expected to interact in various ways with climate change and stream flows, and outcomes for freshwater ecosystems and water quality are uncertain. Managers of freshwater ecosystems and water supplies could benefit from being able to predict the scales of likely changes. This project has developed and applied a linked modelling framework to assess climate change impacts on water quality regimes and ecological responses. The framework is designed to inform water planning and climate adaptation activities. It integrates quantitative tools, and predicts relationships between future climate, human activities, water quality and ecology, thereby filling a gap left by the considerable research effort so far invested in predicting stream flows. The modelling framework allows managers to explore potential changes in the water quality and ecology of freshwater systems in response to plausible scenarios for climate change and management adaptations. Although set up for the Upper Murrumbidgee River catchment in southern NSW and ACT, the framework was planned to be transferable to other regions where suitable data are available. The approach and learning from the project appear to have the potential to be broadly applicable. We selected six climate scenarios representing minor, moderate and major changes in flow characteristics for 1oC and 2oC temperature increases. These were combined with four plausible alternative management adaptations that might be used to modify water supply, urban water demand and stream flow regimes in the Upper Murrumbidgee catchment. The Bayesian Network (BN) model structure we used was developed using both a ‘top down’ and ‘bottom up’ approach. From analyses combined with expert advice, we identified the causal structure linking climate variables to stream flow, water quality attributes, land management and ecological responses (top down). The ‘bottom up’ approach focused on key ecological outcomes and key drivers, and helped produce efficient models. The result was six models for macroinvertebrates, and one for fish. In the macroinvertebrate BN models, nodes were discretised using statistical/empirical derived thresholds using new techniques. The framework made it possible to explore how ecological communities respond to changes in climate and management activities. Particularly, we focused on the effects of water quality and quantity on ecological responses. The models showed a strong regional response reflecting differences across 18 regions in the catchment. In two regions the management alternatives were predicted to have stronger effects than climate change. In three other regions the predicted response to climate change was stronger. Analyses of water quality suggested minor changes in the probability of water quality exceeding thresholds designed to protect aquatic ecosystems. The ‘bottom up’ approach limited the framework’s transferability by being specific to the Upper Murrumbidgee catchment data. Indeed, to meet stakeholder questions models need to be specifically tailored. Therefore the report proposes a general model-building framework for transferring the approach, rather than the models, to other regions.  Please cite this report as: Dyer, F, El Sawah, S, Lucena-Moya, P, Harrison, E, Croke, B, Tschierschke, A, Griffiths, R, Brawata, R, Kath, J, Reynoldson, T, Jakeman, T 2013 Predicting water quality and ecological responses, National Climate Change Adaptation Research Facility, Gold Coast, pp. 110 Changes to climate are predicted to have effects on freshwater streams. Stream flows are likely to change, with implications for freshwater ecosystems and water quality. Other stressors such as population growth, community preferences and management policies can be expected to interact in various ways with climate change and stream flows, and outcomes for freshwater ecosystems and water quality are uncertain. Managers of freshwater ecosystems and water supplies could benefit from being able to predict the scales of likely changes. This project has developed and applied a linked modelling framework to assess climate change impacts on water quality regimes and ecological responses. The framework is designed to inform water planning and climate adaptation activities. It integrates quantitative tools, and predicts relationships between future climate, human activities, water quality and ecology, thereby filling a gap left by the considerable research effort so far invested in predicting stream flows. The modelling framework allows managers to explore potential changes in the water quality and ecology of freshwater systems in response to plausible scenarios for climate change and management adaptations. Although set up for the Upper Murrumbidgee River catchment in southern NSW and ACT, the framework was planned to be transferable to other regions where suitable data are available. The approach and learning from the project appear to have the potential to be broadly applicable. We selected six climate scenarios representing minor, moderate and major changes in flow characteristics for 1oC and 2oC temperature increases. These were combined with four plausible alternative management adaptations that might be used to modify water supply, urban water demand and stream flow regimes in the Upper Murrumbidgee catchment. The Bayesian Network (BN) model structure we used was developed using both a ‘top down’ and ‘bottom up’ approach. From analyses combined with expert advice, we identified the causal structure linking climate variables to stream flow, water quality attributes, land management and ecological responses (top down). The ‘bottom up’ approach focused on key ecological outcomes and key drivers, and helped produce efficient models. The result was six models for macroinvertebrates, and one for fish. In the macroinvertebrate BN models, nodes were discretised using statistical/empirical derived thresholds using new techniques. The framework made it possible to explore how ecological communities respond to changes in climate and management activities. Particularly, we focused on the effects of water quality and quantity on ecological responses. The models showed a strong regional response reflecting differences across 18 regions in the catchment. In two regions the management alternatives were predicted to have stronger effects than climate change. In three other regions the predicted response to climate change was stronger. Analyses of water quality suggested minor changes in the probability of water quality exceeding thresholds designed to protect aquatic ecosystems. The ‘bottom up’ approach limited the framework’s transferability by being specific to the Upper Murrumbidgee catchment data. Indeed, to meet stakeholder questions models need to be specifically tailored. Therefore the report proposes a general model-building framework for transferring the approach, rather than the models, to other regions.&nbsp

The Conservation Of Arboreal Marsupials In The Montane Ash Forests Of The Central Highlands Of Victoria, South-Eastern Australia - VII. Modelling The Persistence Of Leadbeater's Possum In Response To Modified Timber Harvesting Practices

A computer model for Population Viability Analysis (PVA) was used to simulate the relationship between the persistence of populations of the endangered species, Leadbeater's possum, Gymnobelideus leadbeateri and the implementation of a range of possible modified timber harvesting practices in two wood production blocks within the montane ash forests of the central highlands of Victoria, south-eastern Australia. The results of our analyses revealed that under the existing conservation strategies there was a high probability of extinction over the next 150 years in both blocks. Given that timber production areas comprise more than 75% of the distribution of G. leadbeateri, our findings highlight a need for additional conservation measures to enhance the survival prospects of the species. The range of upgraded conservation strategies that were examined included (1) extending the rotation time between logging operations; (2) modifying silvicultural practices to increase the amount of forest retained within each harvested coupe; and (3) permanently withdrawing areas from wood production. All of each of these approaches were found significantly to reduce the probability of extinction of populations of G. leadbeateri. However, when the relative merits of the various strategies were compared, the permanent withdrawal of potential logging coupes from timber harvesting was predicted to be the most efficient approach. Importantly, this strategy would have a number of practical advantages including that it overcomes both (1) the logistic difficulties of ensuring the long-term survival of retained trees within logged areas; and (2) human safety issues arising from implementing modified silvicultural practices. This practical application of PVA to compare the merits of different potential management options has provided new information that will enhance present efforts to conserve G. leadbeateri in wood production areas