Panicum maximum cv. Tanzânia: climate trends and regional pasture production in Brazil

Projected change in forage production under a range of climate scenarios is important for the evaluation of the impacts of global climate change on pasture‐based livestock production systems in Brazil. We evaluated the effects of regional climate trends on Panicum maximum cv. Tanzânia production, predicted by an agro‐meteorological model considering the sum of degree days and corrected by a water availability index. Data from Brazilian weather stations (1963–2009) were considered as the current climate (baseline), and future scenarios, based on contrasting scenarios in terms of increased temperature and atmospheric CO₂ concentrations (high and low increases), were determined for 2013–2040 (2025 scenario) and for 2043–2070 (2055 scenario). Predicted baseline scenarios indicated that there are regional and seasonal variations in P. maximum production related to variation in temperature and water availability during the year. Production was lower in the Northeast region and higher in the rainforest area. Total annual production under future climate scenarios was predicted to increase by up to 20% for most of the Brazilian area, mainly due to temperature increase, according to each climate model and scenario evaluated. The highest increase in forage production is expected to be in the South, Southeast and Central‐west areas of Brazil. In these regions, future climate scenarios will not lead to changes in the seasonal production, with larger increases in productivity during the summer. Climate risk is expected to decrease, as the probability of occurrence of low forage productions will be lower. Due to the predicted increase in temperature and decrease in rainfall in the Northeast area, P. maximum production is expected to decrease, mainly when considering scenarios based on the PRECIS model for the 2055 scenario.     

Life Cycle Assessment and sustainability methodologies for assessing industrial crops, processes and end products

Providing food, energy and materials for the rising global population is a challenge which is compounded by increased pressure on natural resources such as land, water and fossil sources of raw materials. Greenhouse gas (GHG) emissions from human activities have increased with industrial development and population expansion, and it is anticipated that resulting climate change might further limit agricultural productivity, through changes to weather patterns and global availability/distribution of agriculturally productive land. Growing crops as feedstocks for industrial uses is seen as one way of reducing GHG emissions and dependency on fossil resources. However, determining the extent to which the development of crops for industrial use will effect GHG balances and provide for a more energy efficient manufacturing system requires the development and use of appropriate calculation methodologies.Research at the Porter Institute has identified over 250 different scenarios for bioenergy production systems using commodity crops. In order to rationalise this complexity and diversity, a modular approach to Life Cycle Assessment (LCA) and sustainability analysis has been taken. This allows characterisation of discrete sections of supply chains and enables comparisons to be made between different crop production systems, different process systems and different end product uses. The purposes of this paper are to introduce the concepts of biofuel GHG and sustainability metrics, to introduce the approach taken by our organization and to use the example of UK grown willow in a lignocellulosic ethanol production system to demonstrate how GHG emission outcomes can be reviewed for “new” crops and technologies.The results show a range of variation, in both growing and process systems and how outcomes such as energy and GHG balances can be affected by various activities.LCA methodologies provide data to inform governments and industry of the potential specific supply chains may have for energy and GHG saving. However, methodological approaches can also affect assessment outcomes. Unresolved issues in LCA methodology must also be evaluated e.g. impacts resulting from land use change. Sustainability assessments of crop growing systems, irrespective of the end use, also assist in the assessment of environmental impacts of supply chains. However, it is critical that data continue to be collected, analysed and reviewed, to ensure that the most appropriate crops are grown and processed for the most appropriate end use.     

A multi-field bio-economic model of irrigated grain-cotton farming systems

We present a participatory modelling framework that integrates information from interviews and discussions with farmers and consultants, with dynamic bio-economic models to answer complex questions on the allocation of limited resources at the farm business level. Interviews and discussions with farmers were used to: describe the farm business; identify relevant research questions; identify potential solutions; and discuss and learn from the whole-farm simulations. The simulations are done using a whole-farm, multi-field configuration of APSIM (APSFarm). APSFarm results were validated against farmers’ experience. Once the model was accepted by the participating farmers as a fair representation of their farm business, the model was used to explore changes in the tactical or strategic management of the farm and results were then discussed to identify feasible options for improvement.Here we describe the modelling framework and present an example of the application of integrative whole farm system tools to answer relevant questions from an irrigated farm business case study near Dalby (151.27E - 27.17S), Queensland, Australia. Results indicated that even though cotton crops generates more farm income per hectare a more diversified rotation with less cotton would be relatively more profitable, with no increase in risk, as a more cotton dominated traditional rotation. Results are discussed in terms of the benefits and constraints from developing and applying more integrative approaches to represent farm businesses and their management in participatory research projects with the aim of designing more profitable and sustainable irrigated farming systems.     

Impact of climate change on paddy field irrigation in southern Taiwan

Climate change can have a serious impact on water resources. The main agricultural product in southern Taiwan is rice, the planting of which consumes far more water than other crops. This makes agriculture in Taiwan especially vulnerable to climate change. In this study, we used the generalized watershed loading functions (GWLF) hydrological model to simulate the discharge of the Kaoping River under climate change scenarios A2 and B2 as released by the Intergovernmental Panel on Climate Change. We discussed the potential impact of climate change on water resources based on the results of GWLF simulations carried out using rainfall and temperature data from five general circulation models (GCMs). The simulation results indicate that river discharge in the wet season increases significantly, and decreases in the dry season. The discharge variations from using the various GCMs as inputs fall within the range of ?26 to +15 % for the dry season and ?10 to +82 % for the wet season. The variation in available water will seriously impact the first period rice farming (the period between the beginning of January and the end of May) in southern Taiwan. Consequently, effective reduction in conveyance loss in the irrigation canal systems and proper fallowing of paddy fields will be the main challenges to Taiwan’s agricultural sector for alleviating the impact of climate change. For further decision making, we show the effects of adapting to climate change by various degrees of the following two methods: fallowing paddy fields to various degrees and reducing conveyance loss in irrigation canal systems.     

Methodologies for simulating impacts of climate change on crop production

Ecophysiological models are widely used to forecast potential impacts of climate change on future agricultural productivity and to examine options for adaptation by local stakeholders and policy makers. However, protocols followed in such assessments vary to such an extent that they constrain cross-study syntheses and increase the potential for bias in projected impacts. We reviewed 221 peer-reviewed papers that used crop simulation models to examine diverse aspects of how climate change might affect agricultural systems. Six subject areas were examined: target crops and regions; the crop model(s) used and their characteristics; sources and application of data on [CO₂] and climate; impact parameters evaluated; assessment of variability or risk; and adaptation strategies. Wheat, maize, soybean and rice were considered in approximately 170 papers. The USA (55 papers) and Europe (64 papers) were the dominant regions studied. The most frequent approach used to simulate response to CO₂ involved adjusting daily radiation use efficiency (RUE) and transpiration, precluding consideration of the interacting effects of CO₂, stomatal conductance and canopy temperature, which are expected to exacerbate effects of global warming. The assumed baseline [CO₂] typically corresponded to conditions 10-30 years earlier than the date the paper was accepted, exaggerating the relative impacts of increased [CO₂]. Due in part to the diverse scenarios for increases in greenhouse gas emissions, assumed future [CO₂] also varied greatly, further complicating comparisons among studies. Papers considering adaptation predominantly examined changes in planting dates and cultivars; only 20 papers tested different tillage practices or crop rotations. Risk was quantified in over half the papers, mainly in relation to variability in yield or effects of water deficits, but the limited consideration of other factors affecting risk beside climate change per se suggests that impacts of climate change were overestimated relative to background variability. A coordinated crop, climate and soil data resource would allow researchers to focus on underlying science. More extensive model intercomparison, facilitated by modular software, should strengthen the biological realism of predictions and clarify the limits of our ability to forecast agricultural impacts of climate change on crop production and associated food security as well as to evaluate potential for adaptation.     

The Potential Effect of Climate Change and Elevated Air Carbon Dioxide on Agricultural Crop Production in Central and Southeastern Europe

SUMMARY

The vulnerability and adaptation of major agricultural crops to different soils in Austria and Bulgaria under a changing climate and elevated air CO₂ were investigated. Several incremental and transient GCM climate change scenarios were created and applied. Warming will decrease the crop-growing duration of the selected crops in the regions of interest. All GCM scenarios, including the climate change effect only, projected reductions in grain yield of winter wheat and spring barley, caused by a shorter crop-growing period. However, when the direct effect of an increased CO₂ level was assumed, most GCM climate change scenarios projected an increase in wheat and barley yield and especially in soybean yield. An increased level of CO₂ alone had no significant impact on the simulated maize yield reductions under climate change.     

The impact of climate change on global food supply and demand, food prices, and land use

Climate change induced crop yield change affects food production of countries to varying degrees, depending on the location of the farming activities. Differentiated yield changes of crops may lead to reallocation of agricultural land among uses. Key food exporters may reshuffle due to diverse climate change impact on crop farming among countries. We use a multi-region, multi-sector computable general equilibrium (CGE) model, which considers crop suitability of land in the optimal reallocation decision of land between uses, to simulate the impact on global food production, prices, and land use of crop yield change due to climate change as projected under the IPCC SRES scenario A2. Our findings show that developing countries are more adversely affected by climate change than developed countries. Developed countries are mostly located in higher latitudes, and climate change benefits the crop yield of these areas. In contrast, developing countries of the lower latitudes suffer from the reduction in crop yield being induced by climate change. Considering the fast growing population in the developing world, developed countries are expected to serve as the world’s key food exporters by 2020 should the climate change occurs as scenario A2 indicates.     

Sustainable intensification in the production of grass and forage crops in the Low Countries of north‐west Europe

Production of grass and fodder crops in areas under intensive production systems in the Low Countries of north‐west Europe faces a number of threats related to increased regulations, scarcity of land and restricted freedom of use of the land, and from climate change. Grassland‐based farmers are pushed to do more with less, i.e., to improve eco‐efficiency, and this requires “more knowledge per ha.” This article argues that progress in variety breeding, the application of crop rotation instead of monocultures, a proper use of catch crops, ley‐arable farming and overall good management offer realistic opportunities to cope with current threats. A large capacity for mechanization also allows improvement of net yields per ha. This article highlights that progress in plant breeding has compensated for yield declines caused by nutrient‐input restrictions in forage maize (Zea mays L.). Both forage maize and grass–clover can take advantages of ley‐arable farming, and crop rotation provides an insurance against the effects of low‐yielding years and a buffer for reduced nutrient inputs.     

Assessing the impact of climate change on basin-average annual typhoon rainfalls with consideration of multisite correlation

The effects of climate change on synoptic scale storms like typhoons can have profound impacts on practices of water resources management. A stochastic multisite simulation approach is proposed for assessing the impact of climate changes on basin-average annual typhoon rainfalls (BATRs) under certain synthesized climate change scenarios. Number of typhoon events and event-total rainfalls are considered as random variables characterized by the Poisson and gamma distributions, respectively. The correlation structure of event-total rainfalls at different rainfall stations is found to be significant (higher than 0.80) and plays a crucial role in the proposed stochastic simulation approach. Basin-average annual typhoon rainfalls were simulated for the Shihmen Reservoir watershed in northern Taiwan by considering changes in the mean values of annual number of typhoon events and event-total rainfalls, while assuming the correlation structure of multisite typhoon rainfalls to remain unchanged. The simulation results indicate that changes in expected values of BATR can be easily projected with simpler models; however, changes in extreme properties of BATR are more complicated. Comparing to changes in expected values of BATRs, lesser changes in more extreme events can be observed. This is due to the reduction in coefficient of skewness of gamma distribution BATR under different climate change scenarios. With consideration of the multisite correlation structure, changes in BATRs become more significant. Thus, in assessing the impacts of climate change on many hydrological and environmental variables which exhibit significant spatial correlation pattern, the multisite correlation structure needs to be taken into consideration.     

Changing global risk of invading greenbug Schizaphis graminum under climate change

The geographical range, abundance, growth rate, survival and mortality of insects are largely influenced by abiotic factors such as temperature and humidity. When suitable, these factors can positively influence the abundance of insect pests. It is in this light that the influence of climate change, particularly global warming, has direct bearing to crop protection. In this study, we simulated the potential distribution of the greenbug or wheat aphid Schizaphis graminum (Rondani) (Aphididae), a major global pest of wheat, using the climate matching tool CLIMEX (CLIMatic indEX) in global warming scenarios. To predict the potential distribution of the insect on CLIMEX at time periods 2030, 2070 and 2100, we utilize two global climate models (GCMs) at two emission scenarios. The result of CLIMEX modelling shows that the favourable climatic areas for S. graminum are subtropical to temperate at the current time. With global warming, under different scenarios current suitable and highly suitable areas in the northern hemisphere are expected to expand to higher latitudes by 2030 towards 2100; while areas in the southern hemisphere, where the pest’s living areas already have high temperature ranges, the occurrence of the pest will contract by 2030 since temperatures will exceed its heat limits. This study assists in predicting the potential risk areas that may be threatened by this pest in the future, providing supportive information for agricultural management practices and aid in the preparation of strategic plans to avoid possible economic damage posed by future expansion of the pest population due to climate change.     

The Role of Cover Crops in North American Cropping Systems

SUMMARY

The benefits of cover crops in cropping systems have long been recognized. Legumes have historically been used lo provide biologically fixed nitrogen to cash crops, and it has been shown that soil erosion can be slowed significantly with even minimal amounts of soil cover during vulnerable times of year. The role of cover crops in North American farming systems is expanding to include management of weeds, disease and pests, and overall enhancement of soil quality through organic matter enrichment, improved nutrient cycling and reduction of soil compaction. While the predominant temporal niche for cover crops in North America remains the winter, other opportunities in diverse cropping systems exist for cover crop inclusion, such as summer fallow, living mulches or full-year fallow crops. To date, the use of cover crops is constrained by economic, biological, and farm operational factors, but farmer education, continued research, and government policy changes can aid in overcoming existing barriers to adoption.     

Assessing the impact of climate change on the land hydrology in Taiwan

The gradually increased temperature resulting from the enhanced greenhouse effects has been found to be an important factor of changes to the global climate which in turn might significantly affect the Earth's hydrological cycles. The possible outcomes of warming climate are changes of precipitation, surface runoff, evapotranspiration, and frequency of extreme weather events, such as floods and droughts. However, such changes at the global scale may not reflect the variations on a regional scale, and more so at the local scale. In this study, a physically based water balance model was applied to study the impact of climate change on the land hydrology, focusing on trends of surface runoff, evapotranspiration, and infiltration in Taiwan. Model forcing of composite temperatures and precipitations were generated by a weather generation model in association with nine climate change scenarios, including outputs of equilibrium experiments and special reports on emissions scenarios, from the IPCC. Although discrepancies among different climate change scenarios are significant, the trend of more extreme precipitations and surface runoffs were observed in most scenarios' runs. The increase of evapotranspiration in both wet and dry seasons is persistent among different scenarios throughout the island due to the projected consistently higher temperature. Although the trends of infiltration for wet and dry seasons are opposite in curtain scenarios, a decreased yearly infiltration was found in most cases as the result of increased precipitation intensity and more evapotranspiration. Timely adaption measures for water resources managements and natural hazard mitigations are required to face these changes of land hydrology components under changing climate.     

Predicting the water use-demand as a climate change adaptation strategy for rice planting crops in the Long Xuyen Quadrangle Delta

Paddy and Water Environment - This work evaluates the impacts of climate change on water use-demand of three rice planting crops including winter–spring (WS), summer–autumn (SA) and...     

Grasslands in ‘Old World’ and ‘New World’ Mediterranean‐climate zones: past trends,current status and future research priorities

Despite their ecological, economic and social importance, grasslands in areas with Mediterranean climates continue to receive limited scientific, political and media attention. The main objectives of this review are to compare and contrast dryland grasslands in the ‘Old World’ regions of the Mediterranean basin (southern Europe, western Asia and North Africa) with those of ‘New World’ regions with Mediterranean climates (Australia and Chile) and to identify common research priorities. The common characteristics and differences in climate, soils, native vegetation, importance of the livestock sector and the socio‐economic background for the different Mediterranean environments are examined. Past trends and the current status of temporary and permanent Mediterranean grasslands are also described. Some common issues between these regions are as follows: (i) adaptation to climate change; (ii) increasing persistence and drought survival of both annual and perennial species; (iii) the important role of forage legumes; (iv) maintaining grassland plant diversity; and (v) improved ecosystem services, such as carbon sequestration, control of soil erosion and wildfires, and preservation of both wild and domestic biodiversity. The favourable climate in these regions, which allows year‐round grazing and the growth of legumes, should be exploited to improve the sustainability of grassland‐based, extensive farming systems and the quality of their animal products, while at the same time improving ecosystem services. The decreasing support for grassland research and development programmes requires increased international scientific and technical cooperation among the few institutions operating in the different Mediterranean‐climate areas of the World to provide innovative and sustainable solutions to farmers.     

Converting rice paddy to dry land farming in the Tai Lake Basin,China: toward an understanding of environmental and economic impacts

Water pollution is a well-known major problem in the Tai Lake Basin, China. Compared to industries and domestic sewage, non-point pollution from agriculture is more difficult to detect, measure, and control. Therefore, a range of policies has been formulated, among which is that of ‘adjustment of the planting structure.’ However, this policy during implementation has been used to simply convert paddy fields to dry land and food crops to cash crops. More surprisingly, to date, no research has provided evidence that such an agricultural land-use change contributes to the reduction of agricultural nutrient pollution. Based on an extensive farm survey, this research finds that conversion of rice paddy to dry land farming has not generated a positive effect on nutrient pollution control. It is estimated that nitrogen runoff from agricultural land has increased by 11 %, while phosphorus runoff has increased more than two times since land-use patterns changed, as farmers are inclined to apply more fertilizer on dry land than in paddy fields. However, this agricultural land-use change is economically effective as land-use conversion increases the net profits of farming in a significant way. It is demonstrated that, compared to environmental concerns, economic considerations are seen to have greater benefits after such an adjustment in the planting structure. These findings have important implications for policy making by local authorities in their efforts to improve environmental management and pollution control in their territories.     

我国油菜生产区域布局演变和成因分析

本文对我国油菜生产区域布局的演变和成因进行了分析。结果表明,目前我国以长江流域冬油菜区、北方春油菜区为优势发展区域布局格局的形成,除了气候、耕作制度、种植习惯和与粮食作物的关系等原因外,科技创新和国家优势区域布局的双重推动起到了至关重要的作用。根据优势区的发展特点和趋势,提出了相关政策建议。     

Current status,opportunities, and challenges of cover cropping for sustainable dryland farming in the Southern Great Plains

Cropping systems that integrate cover crops into crop rotations, reduce tillage intensity and frequency, and maintain residue cover have the potential to improve agricultural sustainability in drylands. However, there is much yet to learn about the benefits of cover crops in sustainable dryland farming in the southern Great Plains (SGP). We reviewed the literature on the effects of cover crops on soil organic carbon (SOC), nitrogen, soil water conservation, and crop yields in dryland cropping systems of the US Great Plains (GP), and analyzed the opportunities and challenges for integrating cover crops into dryland crop-fallow systems of the SGP. Majority of the studies in the central Great Plains (CGP) and the northern Great Plains (NGP) of the United States suggest that cover cropping improves sustainability of cropping systems through their positive effects on SOC accumulation, nutrient cycling, soil erosion control, weed suppression, and soil health improvement. However, integrating cover crops into dryland cropping systems of the SGP faces challenges because of low quantity of soil-water availability. More research on the tradeoff between water use and other agroecosystem benefits of cover cropping is required to successfully integrate cover crops into dryland cropping systems in the SGP.     

Climate‐change effects and adaptation options for temperate pasture‐based dairy farming systems: a review

Temperate pasture‐based dairy farming systems with low input of supplementary feed are vulnerable to changes in climate through alterations in feed supply and nutritive value. Although current systems in New Zealand (NZ) and southeast Australia have been successful in adapting to variable weather conditions, they will need to undergo further changes to continue to profit in the future. This review describes predicted changes in climate in NZ and southeast Australia, likely effects on the feedbase used in the pasture‐based dairy industry and the flow‐on effect on milk‐solids production and profitability. Potential adaptation options that will allow farmers to take advantage of new opportunities and minimize any negative impacts of climate change are also identified. For example, in many regions, annual pasture production is predicted to increase due to carbon dioxide fertilization and warmer temperatures during winter/spring. Production may decline, however, in regions with either reduced rainfall or severe flooding. Should this occur, farmers could strategically use supplementary feed, reduce stocking rates, irrigate or sow alternative plant species with greater drought tolerance. Pasture‐based dairy systems have high levels of adaptive capacity, and there are opportunities to continue to improve production efficiencies particularly where rainfall change is small. Further investigation into possible adaptation options is required to determine their impact on milk‐solids production and profitability, as well as to identify additional options.     

Optimizing the growth of forage and grain legumes on low pH soils through the application of superior Rhizobium leguminosarum biovar viciae strains

Climate variability and current farming practices have led to declining soil fertility and pH, with a heavy reliance on fertilizers and herbicides. The addition of forage and grain legumes to farming systems not only improves soil health but also increases farm profitability through nitrogen (N) fertilizer cost offsets. However, the formation of effective symbioses between legumes and rhizobia can be unreliable and is considered at risk when combined with dry sowing practices such as those that have been designed to obviate effects of climate change. This research was initiated to improve the robustness of the legume/rhizobia symbiosis in low pH, infertile and dry soils. Production from two cultivars of field pea (Pisum sativum) and two species of vetch (Vicia spp.), and symbiotic outcomes when inoculated with a range of experimental rhizobial strains (Rhizobium leguminosarum biovar viciae), was assessed in broad acre field trials which simulated farmer practice. New rhizobia strains increased nodulation, N fixation, produced more biomass and higher seed yield than comparator commercial strains. Strain WSM4643 also demonstrated superior survival when desiccated compared to current commercial strains in the laboratory and on seed when delivered as inoculant in peat carriers. WSM4643 is a suitable prospect for a commercial inoculant in Australia and other agricultural areas of the world where growing peas and vetch on soils generally considered problematic for this legume/rhizobia symbiosis. A particular advantage of WSM4643 may be that it potentiates sowing inoculated legumes into dry soil, which is a contemporary response by farmers to climate variation.     

基于适应性调整的豫南地区水稻生产对未来气候变化的响应

选取河南信阳市9个取样点和单季稻早、中、晚熟3个代表性品种开展气候变化影响的评价研究。根据政府间气候变化委员会(IPCC)排放情景特别报告(SRES)中的A2、B2情景并结合区域气候模式(PRECIS),生成信阳市9个取样点基准时段(1961-1990年)和未来时段(2021-2050年)的逐日气象资料。利用ORYZA-V3模型,在考虑未来CO_2的直接增益效应情况下,模拟分析了未来气候变化对水稻生产的影响。在此基础上,模拟分析了未来不同情景下水稻生产可能的适应性调整方案,最后得出研究区域的水稻生产经过适应性调整后的产量、稳产性以及豫南地区水稻总产的变化。结果显示,未来气候变化中,若不进行适应性调整,在不考虑CO_2直接增益效应情况下,信阳地区在A2情景下的模拟产量较基准阶段减产14.1%,B2情景下减产8.6%。通过品种、播期的调整,并同时考虑CO_2的肥效作用,A2和B2情景下将分别增产17.2%和15.7%。适应性调整后豫南地区的总产在A2和B2情景下较基准阶段将分别增产14.8%和13.2%。因此,在未来气候变化的评价研究中,将作物生产的适应性调整考虑在内,不仅更为科学合理,也更为乐观。