Economic Trade-Offs of Novel Forage Use in Livestock Production Systems: Insights from Australia

Globally, livestock are a major component of agricultural systems and natural resource management, as well as an important contributor to nutrition and livelihoods, but are often undervalued (Herrero et al., 2009). In Australia, livestock production systems occupy half of the available land and contribute to ~50% of gross agricultural production. The main livestock systems are beef cattle grazing at low intensity in the arid and semi-arid regions of northern and central Australia; and sheep flocks integrated in crop-livestock systems in the temperate zone of southern Australia (Bell et al., 2014). Despite increased physical productivity (changes in outputs relative to inputs) in both sectors, real incomes have declined due to adverse terms of trade (Ash et al., 2015). Pressures are compounded by increasing public scrutiny on environmental performance and need to develop sustainable production practices. This situation has renewed the focus on improving the efficiency of current livestock systems, and coupling improvements in profitability to improvements in the natural resources. Diversifying feeding systems to overcome deficiencies in energy or nutrient supply can increase productivity and profitability, along with resource-use efficiency (Ash et al., 2015). In the north, irrigated forage crops have been identified as an avenue for promoting productivity through faster finishing of cattle, increased beef quality and reduced pressure on rangelands. In the south, plantings of forage shrubs have the potential to improve animal performance, economic returns and environmental management. With better understanding of the economic trade-offs and riskiness involved in the use of novel forages in livestock production systems, there is the opportunity to better design and deliver diversification options

Sixty years of irrigated wheat yield increase in the Yaqui Valley of Mexico: Past drivers, prospects and sustainability

Continued global wheat yield increase (about 1.3% p.a. for 2000–2019) remains an essential condition for greater world food security. Relevant to this challenge is the rise in average farm yield (FY) of irrigated spring wheat in the Yaqui Valley of northwest Mexico from 2 to 7 t/ha between 1960 and 2019. Since the early 1950s the region has been the prime target of wheat research by the International Maize and Wheat Improvement Centre (CIMMYT) and its predecessors, research still having significant impact on wheat in the developing world, a grouping that today delivers more than half the world's wheat. FY increase was investigated in detail by dividing the interval into three 20-year periods, correcting FY for the strong influence of inter-annual variation in January to March minimum temperature (Tmin J-M, warming lowering yield around 7%/°C) and measuring the remaining linear increase in FY (Fischer et al., 2022). Total yield increase, corrected for Tmin J-M and CO2 rise, relative to average yield in each period, was 4.17%, 0.47%, and 1.59% p.a. for 1960–79, 1980–99, and 2000–19, respectively. The breeding component, estimated by the increase in the Varietal Yield Index in farmers’ fields, rose at 0.97%, 0.49%, and 0.71% p.a., respectively. The remaining yield change (3.16, −0.02% and 0.87% p.a., respectively) comprised the net effect of improved crop management (agronomic progress) plus that of off-farm changes, together here called agronomy+. Major changes in agronomy included: a large increase in fertiliser N use, benefitting early on from a large positive variety × N interaction; in the second period a switch to planting on raised beds and a decline in rotational diversity; and in the final period, consolidation of operational crop units and probably more skilful and timely management. Off-farm developments saw strong government financial support in the first period, but in the second period breakdown of the traditional small holder land system and withdrawal of government support. The last period saw better prices and improved access to technical advice. Breeding progress is expected to continue in the Yaqui Valley but at a slowly diminishing rate (currently 0.66% p.a.), while progress from new agronomy appears limited. Although FY gaps are small, some gap closing remains possible, and 1.2% p.a. FY progress is estimated for the next 20 years in the absence of new technologies. World wheat food security without area increase will increasingly depend on developing countries where yield gaps are generally wider and gap closing prospects better. Biophysical sustainability of the Yaqui Valley wheat system is moderately good but N management and diversity can be improved

Decision Support Systems for Weed Management

Editors: Guillermo R. Chantre, José L. González-Andújar.Weed management Decision Support Systems (DSS) are increasingly important computer-based tools for modern agriculture. Nowadays, extensive agriculture has become highly dependent on external inputs and both economic costs, as well the negative environmental impact of agricultural activities, demands knowledge-based technology for the optimization and protection of non-renewable resources. In this context, weed management strategies should aim to maximize economic profit by preserving and enhancing agricultural systems. Although previous contributions focusing on weed biology and weed management provide valuable insight on many aspects of weed species ecology and practical guides for weed control, no attempts have been made to highlight the forthcoming importance of DSS in weed management. This book is a first attempt to integrate 'concepts and practice' providing a novel guide to the state-of-art of DSS and the future prospects which hopefully would be of interest to higher-level students, academics and professionals in related areas

Crop Updates 2001 - Weeds

This session covers forty six papers from different authors: 1. INTRODUCTION, Vanessa Stewart, Agriculture Western Australia PLENARY 2. Wild radish – the implications for our rotations, David Bowran, Centre for Cropping Systems INTEGRATED WEED MANAGEMENT IWM system studies/demonstration sites 3. Integrated weed management: Cadoux, Alexandra Wallace, Agriculture Western Australia 4. A system approach to managing resistant ryegrass, Bill Roy, Agricultural Consulting and Research Services Pty Ltd, York 5. Long term herbicide resistance demonstration, Peter Newman, Agriculture Western Australia, Cameron Weeks, Tony Blake and Dave Nicholson 6. Integrated weed management: Katanning, Alexandra Wallace, Agriculture Western Australia 7. Integrated weed management: Merredin, Vanessa Stewart, Agriculture Western Australia 8. Short term pasture phases for weed control, Clinton Revell and Candy Hudson, Agriculture Western Australia Weed biology – implications for IWM 9. Competitivness of wild radish in a wheat-lupin rotation , Abul Hashem, Nerys Wilkins, and Terry Piper, Agriculture Western Australia 10. Population explosion and persistence of wild radish in a wheat-lupin rotation, Abul Hashem, Nerys Wilkins, Aik Cheam and Terry Piper , Agriculture Western Australia 11. Variation is seed dormancy and management of annual ryegrass, Amanda Ellery and Ross Chapman, CSIRO 12. Can we eradicate barley grass, Sally Peltzer, Agriculture Western Australia Adoption and modelling 13. Where to with RIM? Vanessa Stewart1 and Robert Barrett-Lennard2, 1Agriculture Western Australia, 2Western Australian Herbicide Resistance Initiative (WAHRI) 14. Multi-species RIM model, Marta Monjardino1,2, David Pannell2 and Stephen Powles1 1Western Australian Herbicide Resistance Initiative (WAHRI), 2ARE, University of Western Australia 15. What causes WA grain growers to adopt IWM practices? Rick Llewellyn, WAHRI/ARE, Faculty of Agriculture, University of WA New options for IWM? 16. Fuzzy tramlines for more yield and less weeds, Paul Blackwell Agriculture Western Australia, and Maurice Black, Harbour Lights Estate, Geraldton 17. Inter-row knockdowns for profitable lupins, Paul Blackwell, Agriculture Western Australia and Miles Obst, Farmer Mingenew 18. Row cropping and weed control in lupins, Mike Collins and Julie Roche, Agriculture Western Australia 19. Cross seedimg suppresses annual ryegrass and increases wheat yield, Abul Hashem, Dave Nicholson and Nerys Wilkins Agriculture Western Australia 20. Weed control by chaff burial, Mike Collins, Agriculture Western Australia HERBICIDE RESISTANCE 21. Resistance in wild oats to Fop and Dim herbicides in Western Australia, Abul Hashem and Harmohinder Dhammu, Agriculture Western Australia 22. Triazine and diflufenican resistance in wild radish: what it means to the lupin industry, Aik Cheam, Siew Lee, David Nicholson and Peter Newman, Agriculture Western Australia 23. Comparison if in situ v seed testing for determining herbicide resistance, Bill Roy, Agricultural Consulting and Research Services Pty Ltd, York HERBICIDE TOLERANCE 24. Phenoxy herbicide tolerance of wheat, Peter Newman and Dave Nicholson, Agriculture Western Australia 25. Tolerance of wheat to phenoxy herbicides, Harmohinder S. Dhammu, Terry Piper and Mario F. D\u27Antuono, Agriculture Western Australia 26. Herbicide tolerance of new wheats, Harmohinder S. Dhammu, Terry Piper and David F. Nicholson, Agriculture Western Australia 27. Herbicide tolerance of durum wheats, Harmohinder S. Dhammu, Terry Piper and David F. Nicholson, Agriculture Western Australia 28. Herbicide tolerance of new field pea varieties, Harmohinder S. Dhammu, Terry Piper, David F. Nicholson, and Mario F. D\u27Antuono, Agriculture Western Australia 29. Herbicide tolerance of Cooke field peas on marginal soil, Harmohinder S. Dhammu, Terry Piper, David F. Nicholson, and Mario F. D\u27Antuono, Agriculture Western Australia 30. Herbicide tolerance of some annual pasture legumes adapted to coarse textured sandy soils, Clinton Revell and Ian Rose, Agriculture Western Australia 31 Herbicide tolerance of some annual pasture legumes adapted to fine textured clay soils, Clinton Revell and Ian Rose, Agriculture Western Australia WEED CONTROL IN LUCERNE 32. Management of weeds for Lucerne establishment, Diana Fedorenko, Clayton Butterly, Stuart McAlpine, Terry Piper and David Bowran, Centre for Cropping Systems, Agriculture Western Australia 33. Management of weeds in the second year of Lucerne, Diana Fedorenko, Clayton Butterly, Stuart McAlpine, Terry Piper and David Bowran, Centre for Cropping Systems, Agriculture Western Australia 34. Residual effects of weed management in the third year of Lucerne, Diana Fedorenko, Clayton Butterly, Stuart McAlpine, Terry Piper and David Bowran, Centre for Cropping Systems, Agriculture Western Australia 35. Herbicide tolerance and weed control in Lucerne, Peter Newman, Dave Nicholson and Keith Devenish Agriculture Western Australia HERBICIDES – NEW PRODUCTS/PRODUCE USES; USE New products or product use 36. New herbicide options for canola, John Moore and Paul Matson, Agriculture Western Australia 37. Chemical broadleaf weed management in Peaola, Shannon Barraclough and Lionel Martin, Muresk Institute of Agriculture, Curtin University of Technology 38. Balance® - a new broad leaf herbicide for the chickpea industry, Mike Clarke, Jonas Hodgson and Lawrence Price, Aventis CropScience 39. Marshmallow – robust herbicide strategies, Craig Brown, IAMA Agribusiness 40. Affinity DF – a prospective option for selective in-crop marshmallow control, Gordon Cumming, Technical Officer, Crop Care Australasia 41. A new formulation of Carfentrazone-ethyl for pre-seeding knockdown control of broadleaved weeds including Marshmallow, Gordon Cumming, Technical Officer, Crop Care Australasia Herbicide use 42. Autumn applied trifluralin can be effective! Bill Crabtree, Scientific Officer, Western Australian No-Tillage Farmers Association 43. Which knockdown herbicide for small ryegrass? Peter Newman and Dave Nicholson, Agriculture Western Australia 44. Poor radish control with Group D herbicides in lupins, Peter Newman and Dave Nicholson, Agriculture Western Australia WEED ISSUES 45. Distribution and incidence of aphids and barley yellow dwarf virus in over-summering grasses in the WA wheatbelt, Jenny Hawkes and Roger Jones, CLIMA and Agriculture Western Australia 46. e-weed, Vanessa Stewart, Agriculture Western Australia CONTRIBUTING AUTHOR CONTACT DETAIL

Sustainable intensification with irrigation raises farm profit despite climate emergency

Societal Impact Statement Despite comprising a small proportion of global agricultural land use, irrigated agriculture is enormously important to the global agricultural economy. Burgeoning food demand driven by population growth—together with reduced food supply caused by the climate crisis—is polarising the existing tension between water used for agricultural production versus that required for environmental conservation. We show that sustainable intensification via more diverse crop rotations, more efficient water application infrastructure and greater farm area under irrigation is conducive to greater farm business profitability under future climates. Summary • Research aimed at improving crop productivity often does not account for the complexity of real farms underpinned by land-use changes in space and time. • Here, we demonstrate how a new framework—WaterCan Profit—can be used to elicit such complexity using an irrigated case study farm with four whole-farm adaptation scenarios (Baseline, Diversified, Intensified and Simplified) with four types of irrigated infrastructure (Gravity, Pipe & Riser, Pivot and Drip). • Without adaptation, the climate crisis detrimentally impacted on farm profitability due to the combination of increased evaporative demand and increased drought frequency. Whole-farm intensification—via greater irrigated land use, incorporation of rice, cotton and maize and increased nitrogen fertiliser application—was the only adaptation capable of raising farm productivity under future climates. Diversification through incorporation of grain legumes into crop rotations significantly improved profitability under historical climates; however, profitability of this adaptation declined under future climates. Simplified systems reduced economic risk but also had lower long-term economic returns. • We conclude with four key insights: (1) When assessing whole-farm profit, metrics matter: Diversified systems generally had higher profitability than Intensified systems per unit water, but not per unit land area; (2) gravity-based irrigation infrastructure required the most water, followed by sprinkler systems, whereas Drip irrigation used the least water; (3) whole-farm agronomic adaptation through management and crop genotype had greater impact on productivity compared with changes in irrigation infrastructure; and (4) only whole-farm intensification was able to raise profitability under future climates

The potential contribution of forage shrubs to economic returns and environmental management in Australian dryland agricultural systems

In face of climate change and other environmental challenges, inclusion of perennial forage shrubs in Australian agricultural systems has the potential to deliver multiple benefits: increased whole-farm profitability and improved natural resource management. The profitability of shrubs was investigated using MIDAS (Model of an Integrated Dryland Agricultural System), a bio-economic model of a mixed crop/livestock farming system. We found that including forage shrubs could increase farm profitability by over 20% for an optimal 10% of farm area in shrubs. The impact of shrubs on whole-farm profit accrues primarily through the provision of a predictable supply of “out-of-season” feed, thereby reducing supplementary feed costs, and through the deferment of grazing of pastures, allowing a higher stocking rate and improved animal production. The benefits for natural resource management include improved water use through summer-active, deep-rooted plants, reduced risk of soil erosion through year-round ground cover and/or wind breaks, reduced soil acidification, increased habitat for biodiversity, and effective carbon storage. Forage shrubs also allow for the productive use of marginal soils. Finally, we discuss other benefits of shrubs such as the effect on lambing and on livestock gut health. The principles revealed by the MIDAS modelling have wide application beyond the region

The Value of Roundup-Ready® Canola in a Multi-Weed Farming System

The Multi-species RIM (Resistance and Integrated Management) model is used in this analysis to investigate the value of Roundup-Ready® canola in the simultaneous management of annual ryegrass (Lolium rigidum) and wild radish (Raphanus raphanistrum). It is likely that the transgenic canola variety resistant to the non-selective herbicides glyphosate will soon be introduced in Australian agriculture. The perceived advantage of growing these crops is the potential to control post-emergent weeds with excellent broad-spectrum herbicides, and without the yield penalty evident in triazine-resistant canola (grown widely in WA). This may also help prolong the life of selective herbicides, to which ryegrass and radish can be highly resistant. Therefore, the introduction of genetically modified glyphosate-resistant canola will, other factors being equal, not only increase the options for weed control, but increase the yield of the vast canola crops grown in WA. Conversely, increased usage of the herbicide to which the new crop is resistant can result in the evolution of resistance to that herbicide in weeds. These trade-offs are discussed here

The Value of Green Manuring in the Integrated Management of Herbicide-Resistant Annual Ryegrass (Lolium rigidum)

Herbicide resistance has become a major problem in Australian dryland agriculture. This situation has resulted from the repeated use of herbicides in place of the traditional weed control provided by cultivation and grazing. Farmers have addressed the problem of herbicide resistance by adopting a system of integrated weed management that allows weed control with a range of different techniques and herbicides. One of the non-chemical methods being considered by farmers is “green manuring”, which involves ploughing a healthy growing crop or pasture into the soil in order to prevent weed seed production and provide other benefits. In this study, the trade-offs between the effective weed control and biological benefits provided by green manuring and the large short-term economic losses associated with this practice are investigated for various rotations and patterns of herbicide use. This analysis is conducted using RIM, a bio-economic management model for ryegrass (Lolium rigidum)