Agricultural Science Commons^™

Assessing Resilience Of Pasture Production To Climatic Changes, Brendan R. Cullen, Richard P. Rawnsley, Richard J. Eckard

IGC Proceedings (1977-2023)

Increasing temperatures and atmospheric carbon dioxide (CO₂) concentrations, together with changes to rainfall patterns, will influence seasonal pasture production; however climate change projections for south eastern Australia are uncertain (CSIRO and BoM 2007). Despite this, climate change impact assessments generally rely on specific climate projections, but in this study an alternative approach was developed to test the resilience of production to incremental changes in climate.

Impacts Of Projected Climate Change On Pasture Growth And Safe Carrying Capacities For Three Extensive Grazing Land Regions In Northern Australia, Giselle L. Whish, Robyn A. Cowley, Lester I. Pahl, Joe C. Scanlan, Neil D. Macleod

IGC Proceedings (1977-2023)

The northern beef industry is a major component of the regional economies of Queensland, Northern Territory and northern Western Australia, and has contributed an estimated $5 billion to Australia’s economy in 2009-10. Projected climate change will have an adverse impact on Australia’s agricultural production (McKeon et al. 2008) with an expected 3.5% decline in beef production in northern Australia by 2030 (Heyhoe et al. 2008). The GRASP pasture production model (McKeon et al. 2000) has been used to evaluate impacts of climate change in Australia’s rangelands (Crimp et al. 2002, McKeon et al. 2008), with …

Impact On Grassland Biomass From Climate Warming And Drying, Suying Li, Li Yang

IGC Proceedings (1977-2023)

It is becoming increasingly urgent to assess the impact of climate change on grassland biomass due to the important role these grasslands play in animal production. The typical steppe in Xilinhot of Inner Mongolia is the most representative vegetation types in the temperate grasslands of the northern China. One means to determine climate change is using the Aridity index (AI, also referred to as the dry degree of climate in this article) that is based on both temperature and precipitation (Arora 2002; Bannayan et al.. 2010; Nastos et al. 2012). The objective of this paper was to indicate how …

Impacts Of Future Climate Change On Net Primary Productivity Of Grassland In Inner Mongolia, China, Qiuyue Li, Xuebiao Pan, Jiaguo Qi, Lizhen Zhang, Xiaoyu Wei, Zhihua Pan, Yinlong Xu

IGC Proceedings (1977-2023)

Net Primary Productivity (NPP) of grassland is a key variable of terrestrial ecosystems and is an important parameter for characterizing carbon cycles in grassland ecosystems. In this research, the Inner Mongolia grassland NPP was calculated using the Miami Model and the impact of climate change on grassland NPP was subsequently analyzed under the Special Report on Emissions Scenarios (SRES) A2, B2, and A1B scenarios, which are inferred from Providing Regional Climates for Impacts Studies (PRECIS) climate model system. The results showed that: (1) the NPP associated with these three scenarios had a similar distribution in Inner Mongolia: the grassland NPP …

Future Climate Change Impacts On Pasture Biomass In Mongolia, Erdenetsetseg Baasandai, Erdenetuya Magsar

IGC Proceedings (1977-2023)

The main objective of this study is to estimate pasture biomass changes in Mongolia using the simulation model CENTURY. For the study framework we used the fenced pasture biomass data from 1960’s to 2008, over 60 meteorological stations and simulation data of the carbon, nitrogen, aboveground and belowground biomass, potential evapotranspiration, evaporation, transpiration and precipitation data across these grasslands. The simulated climatic and other parameters were estimated meteorological station based and their differences between 2 time periods were calculated. With purpose to make comparison of the present situation to the future situation used Climate Change Scenarios under A2, A1B and …

Comparative Analysis Of Climate Change Adaptation Options Across The Southern Australian Livestock Industry, Afshin Ghahramani, Andrew D. Moore

IGC Proceedings (1977-2023)

Climate change is predicted to have a substantial negative effect on the productivity of grasslands across southern Australia (Moore and Ghahramani 2013). We used the GRAZPLAN biophysical simulation models to assess several possible grassland management and animal genetic improvement adaptations under SRES A2 climate change scenario. Simulations spanned the five dimensions of geography, time, global circulation models, enterprise, and adaptations. Impact of climate change was predicted to reduce profitability of livestock industry by 46%, 58%, and 72% at 2030, 2050 and 2070, respectively. Increasing soil fertility could return the average profitability of five livestock enterprises to its historical level at …

Eco-Efficiency Of Forage Production In Northern Germany, Antje Herrmann, Sandra Claus, Christof Kluß, Friedhelm Taube

IGC Proceedings (1977-2023)

A 2-year field experiment was conducted at two sites in Schleswig-Holstein, northern Germany, to quantify and evaluate the carbon footprint of arable forage cropping systems (continuous silage maize, maize-wheat-grass rotation, perennial ryegrass ley) as affected by N fertilizer type and N amount. Total greenhouse gas emission showed a linear increase with N application, with mineral N supply resulting in a higher slope. Product carbon footprint ranged between -66 and 119 kg CO2eq/(GJ NEL) and revealed a quadratic or linear response to fertilizer N input, depending on the cropping system. At N input required for achieving maximum energy yield, perennial ryegrass …

Elevated Co2 Impacts On Grazed Pasture: Long-Term Lessons From The New Zealand Face, Michael B. Dodd

IGC Proceedings (1977-2023)

A grazed pasture Free Air CO₂ Enrichment (FACE) experiment has been operating for almost 15 years in the Rangitikei Region of New Zealand, following earlier work studying CO₂, temperature and moisture effects on pasture in growth chambers. The longer-term results are reviewed with a focus on primary productivity, pasture compositional dynamics, nutrient cycling feedbacks and soil carbon supply. In terms of the direct effects of CO₂ elevated to 475 ppm, increases in primary production were reflected in belowground allocation and legume stimulation, with the latter diminishing in the longer term and annual aboveground net herbage accumulation …

Assessing Climate Change Impacts On Managed Grassland Production Using A Bio-Economic Modelling Approach, Robert Finger, Pierluigi Calanca, Simon Briner

IGC Proceedings (1977-2023)

We develop a bio-economic model that combines the process based grassland simulation model PROGRASS with an economic decision model, which accounts for income risks and yield quality, to derive optimal nitrogen application rates in a grass-clover system in Switzerland. The model is applied to current as well as to future climate conditions. Though nitrogen increases yields, it also leads to a higher variance and more negative skewness of yields, i.e. is risk increasing. Accounting for farmers’ risk aversion thus reduces optimal nitrogen use. We find climate change, ceteris paribus, to lead to higher grassland yields but also to increase the …

Tithonia Diversifolia For Ruminant Nutrition, Rogerio M. Mauricio, Rafael S. Ribeiro, Sylvia R. Silveira, Person L. Silva, Leonardo Calsavara, Luiz G. R. Pereira, Domingos S. C. Paciullo

IGC Proceedings (1977-2023)

India and Brazil lead the world ranking of livestock enteric methane emissions (FAO 2006). According to FAO (2006), Brazil (9.6 Tg of CH4/year) is the highest emitter of methane from cattle, followed by India (8.6 Tg of CH4/year) and the USA (5.1 Tg of CH4/year). In livestock, methane (CH4) formed from enteric fermentation of carbohydrates is primarily responsible for the emissions in the sector. Regarding livestock methane emission, Delgado et al. (2012) evaluated 20 tree and shrub species using in vitro technique and demonstrated a reducing effect on the amount of methane when Tithonia diversifolia was compared with, for …

Herbage Intake, Methane Emissions And Animal Performance Of Steers Grazing Dwarf Elephant Grass With Or Without Access To Arachis Pintoi Pastures, Ederson A. De Andrade, Henrique M. N. Ribeiro-Filho, Diego M. De Liz, João G. R. Almeida, Marcolino F. Miguel, Gutierri T. Raupp, Fabiana R. Ramos, Edison X. Almeida

IGC Proceedings (1977-2023)

The inclusion of legumes in diets based on grass has nutritional benefits due to ingestive and digestive interactions (Niderkorn and Baumont 2009). Moreover, it is speculated that tropical legumes can contribute to reducing the emission of greenhouse gases (GHG) compared to diets exclusively composed of grasses (Archimède et al. 2011). However, under grazing conditions, these advantages are not always possible to obtain. This occurs when the spatial distribution of sward grasses impose limitations on access to legumes by grazing animals (Solomon et al. 2011). This can be the case, for example, when legumes are overlapped by the leaves …

Modelling Adaptation And Mitigation Strategies For Southern Livestock Industries Of Australia, Richard J. Eckard, Richard P. Rawnsley, Brendan R. Cullen, Matthew Bell, Karen Christie

IGC Proceedings (1977-2023)

Climate change will impact on the Australian grazing industries both through mitigation policies and the impact of warmer temperatures, increased atmospheric CO₂ and changed rainfall patterns (Cullen et al. 2009; Eckard et al. 2010). Mechanistic models are useful tools to inform our understanding of the complex interactions between future climates and the soil, plant, animal and management in livestock production systems.

This paper summarises the results of a number of whole farm systems modelling studies investigating likely impacts of climate change, adaptation options and emissions implications for livestock production in southern Australia.

Effect Of Soil Moisture Status And Animal Treading On N2O Emissions And The Effectiveness Of A Nitrification Inhibitor Mitigation Technology, H. J. Di, K. C. Cameron, B. Ball, A. Podolyan, Jizheng He

IGC Proceedings (1977-2023)

Nitrous oxide (N₂O) is a potent greenhouse gas with a long-term global warming potential about 298 times that of carbon dioxide (CO₂). In grazed grassland, most of the N₂O is emitted from nitrogen (N) excreted by the grazing animal, particularly in the animal urine. When the soil is wet, such as that in winter grazing conditions, animal grazing can cause soil structural damage, leading to soil compaction. The combination of a wet soil plus soil compaction is particularly conducive for N₂O production. A nitrification inhibitor technology using dicyandiamide (DCD) has been developed …

The Potential Of Carbon Sequestration And N2O Emissions Due To Different Sward Ages After Grassland Re-Sowing, Thorsten Biegemann, Ralf Loges, Friedhelm Taube

IGC Proceedings (1977-2023)

In order to quantify carbon (C) sequestration and nitrous oxide (N₂O) emission rates from grassland of different sward ages (2, 5 and 18 years) after grassland re-establishment, a 2-year field experiment was conducted on a sandy loam in 2010/2011 (2011/2012). The trial was set up in a randomized plot experiment with three replicates including a control (no N-fertilizer) and a fertilized treatment (240 kg N/ha/year as cattle slurry). N₂O emissions were measured on a weekly basis using the closed chamber method. The soil carbon content was measured twice a year from soil cores. Results showed a …

Challenges And Opportunities For Improving Eco-Efficiency Of Tropical Forage-Based Systems To Mitigate Greenhouse Gas Emissions, Michael Peters, Mario Herrero, Myles Fish, Karl-Heinz Erb, Idupulapati M. Rao, Guntur V. Subbarao, Aracely Castro, Jacobo Arango, Julian Chará, Enrique Murgueitio, Rein Van Der Hoek, Peter Läderach, Glenn Hyman, Jeimar Tapasco, Bernardo Strassburg, Birthe K. Paul, Alvaro Rincón, Rainer Schultze-Kraft, Steve Fonte, Timothy Searchinger

IGC Proceedings (1977-2023)

Forage-based livestock production plays a key role in national and regional economies, for food security and poverty alleviation. Livestock production is also considered as a major contributor to agricultural GHG emissions, however. While demand for livestock products is predicted to continue to increase, there is political and societal pressure both to reduce environmental impacts and to convert some of the pasture area to alternative uses such as crop production and environmental conservation. Thus it is essential to develop approaches for sustainable intensification of livestock systems to mitigate GHG emissions, addressing biophysical, socioeconomic and policy challenges. This paper highlights the potential …

Effects Of Rain Events On Carbon Fluxes From Biological Soil Crusts, Chunping Zhang, Xudong Li, Decao Niu, Hongrong Zhang, Hua Fu

IGC Proceedings (1977-2023)

In dry ecosystems, biological soil crusts (BSCs) have been suggested as one of the factors responsible for the large rate of annual CO₂ net uptake (Xie et al. 2009). However, most studies carried out on carbon (C) fluxes in arid and semi-arid ecosystems, such as soil respiration, have neglected the carbon fluxes from BSCs. Although BSCs are a vital component of the dry-land soil C cycle, few studies have parameterized the conditions required for photosynthesis in BSCs or determined BSCs respiration (Elbert et al. 2009, Castillo-Monroy et al. 2011). Precipitation in dry land is dominated by …

Carbon Density Distribution And Carbon Storage Estimation Under Different Grazing Degradation In The Typical Steppe, Sarula Wu, Xiangyang Hou, Yong Ding, Weibo Ren

IGC Proceedings (1977-2023)

Carbon (C) is a crucial component of living organisms on planet earth, and C cycling is an important symbol of healthy development of the biosphere (Han et al. 1999). Human activity has adversely affected the global C cycle, and contributed to an alteration of climate that will generate discernible feedbacks to all organisms and ecosystems on earth (He et al. 2008). Grasslands are one of the most widely distributed terrestrial ecosystems on the earth and it is estimated that C storage of global grassland ecosystem was 761Gt (1Gt = 09t), which accounts for about 15.2% C storage in …

Effect Of Grazing On Soil Carbon And Nitrogen In Alpine Madow, Eastern Of Tibetan Plateau, Shiqing Li, Zhenggang Guo, Xue Ran, Yuying Shen

IGC Proceedings (1977-2023)

As the grassland ecosystem in the Tibetan Plateau is very fragile, overgrazing likely leads to more serious damages to it than other ecosystems. In the past 30 years, 37% of the alpine meadows have been heavily damaged by grazing causing degradation of native vegetation, a decline in species richness and feed value, and more seriously soil erosion (Six et al. 2004). The impact of grazing on alpine grasslands appears to be hysteresis, as the soil needs more time to recover than the vegetation. So analysing the effect of grazing intensity on soil characteristics is an important way to reveal how …

Carbon Sequestration In Relation To Shrub Size In The Desert Ecosystem, Decao Niu, Hongyang Chen, Shigao Jiang, Li Liu, Hongrong Zhang, Hua Fu

IGC Proceedings (1977-2023)

Desert ecosystems have been reported as the location of the long-sought ‘missing sink’ for atmospheric carbon dioxide and as a potentially important area for carbon sequestering from fossil fuel combustion in the future (Stone 2008). Researchers have found that net uptake of carbon in the Mojave Desert ranged from 102 to 127 g C m2/yr during a 3-year period, which is equivalent to the net ecosystem production of many forest ecosystems with a much higher biomass (Luyssaert et al. 2007; Wohlfahrt et al. 2008). Shrub is the dominant plant of desert ecosystems (Gratani et al. 2011); hence, it …

Distribution Of Soil Organic Carbon Fractions As Related To Land Use And Management In The Loess Plateau, Northern China, Huige Han, Xudong Li, Decao Niu, Hua Fu

IGC Proceedings (1977-2023)

Organic C in the soil is not a uniform material but rather a complex mixture of plant, animal and microbial residues at different stages of decomposition (Post and Kwon 2000). So the dynamics of soil organic carbon (SOC) is usually described by dividing total SOC into different fractions (Six et al. 2002). Of all the different fractions, density defined fractions (light- and heavy fractions) may relate better to specific functions or processes (O’Hara et al. 2006), and the changes in SOC due to land use and management may be partly explained by the way C is allocated in …

Grazing And Soil Carbon, Rooting Around For An Effect, Helen P. King

IGC Proceedings (1977-2023)

There is considerable scientific and policy interest in the effect of different grazing methods on soil organic carbon (SOC) and general acceptance that increasing SOC by changing grazing management is possible. While overgrazing is recognised as a cause of land degradation and historical loss of SOC, a review and modelling by Conant and Paustian (2002) showed that ceasing overgrazing and stocking at appropriate levels can also increase SOC. Other reviews showed no difference in animal or pasture productivity between continuous (CG) and rotational (RG) grazing (Briske et al. 2008); and increases, decreases or no change in SOC with high, …

Long-Term Impacts Of Stocking Rate On Soil Carbon Sequestration In Arid Areas Of South Africa, Deribe G. Talore, Eyob Tesfamariam, Abubeker Hassen, Jean-François Soussana

IGC Proceedings (1977-2023)

Overstocking is one of the most important factors which results in changes of carbon stocks (Reeder and Schuman, 2002) and soil degradation, particularly in sandy soil, vulnerable to degradation through physical erosion. South African (RSA) topsoil is characterized by the low level of organic matter (Du Preez et al. 2011). Like most other African countries, little is known about the level of C sequestration under various grazing strategies in the vast dry grassland areas of RSA. It is well known that long-term studies with various stocking rate would be able to shed light on the level of C sequestration …

Soil Organic Carbon Stocks In A Brazilian Oxisol Under Different Pasture Systems, José C. Pinto, Róberson M. Pimentel, Yuri L. Zinn, Fernanda H. M. Chizzotti

IGC Proceedings (1977-2023)

Pastures are the main land use systems in the world and in Brazil they occupy 115 M ha. A major part of Brazil´s greenhouse gas emissions are due to land use change and agriculture. Livestock production comprises > 90% of methane and about 55% of CO2-equivalent emissions due to agriculture (Cerri et al. 2009). However, productive, well-managed pastures can improve degraded soils and increase soil organic carbon (SOC) stocks through humification of grass and root residues. In order to enhance pasture yields and SOC sequestration, nutrient availability in soils must also be improved, especially for N and P. This work …

Bayesian Modeling For Estimating Cattle’S Dung Position In Pasture, Rena Yoshitoshi, Nariyasu Watanabe, Kensuke Kawamura, Seiichi Sakanoue, Jihyun Lim, Taisuke Yasuda

IGC Proceedings (1977-2023)

Livestock excrement is one of the major sources of greenhouse gas (GHG) emission in pasture. As a first step in evaluating its contribution to overall GHG emissions, an understanding of excretion distribution patterns in pastures is required. Betteridge et al. (2010) describe a urine sensor that detects and logs each urination event of female sheep and cattle. The urine sensor records time and ambient temperature at one-second intervals however, patters of dung distribution are not specified. The objective of this study was to predict spatial distribution of cattle dung. The knowledge of livestock excrement position may be useful for …

Influence Of Grassland Management On Carbon Allocation In A Semiarid Temperate Steppe, Nan Liu, Y. Jun Zhang, H. Ming Kan, W. Jie Lu

IGC Proceedings (1977-2023)

Grazing lands in North China are often excessively grazed and widely degraded, while hay-making lands appear to be in relatively good condition due to grazing exclusion, but they are facing a continuous loss of nutrients in the harvested biomass. In semiarid grasslands, plant productivity and community composition are significantly altered by grazing and haying. Grazing mostly leads to negative effects on aboveground productivity, however root biomass seems to increase with moderate grazing (Gao et al. 2009; Derner et al. 2006), although responses can vary. Aboveground biomass removal can increase C3 grass dominance and productivity (Hofer and Bragg 1981). …

Land Use Intensification Effects On Soil C Dynamics In Subtropical Grazing Land Ecosystems, Maria L. Silveira, Sutie Xu, Julius Adewopo, Kanika S. Inglett

IGC Proceedings (1977-2023)

The impacts of land intensification on carbon (C) responses are important components of soil organic carbon (SOC) management. Grazing land intensification typically involves the use of highly productive plant species that can support greater grazing pressure, removal of higher proportions of site biomass and nutrients during mechanical harvest or grazing, and increased use of fertilizers, particularly N. Current improved grazing land management strategies are aimed at increasing above-ground biomass yield, with less regard for below-ground C dynamics. Because intensive management affects above- and below-ground C inputs (Schuman et al. 1999; Liu et al. 2011a,b), it can therefore have …

Research On Soil Carbon Storage Of Alpine Grassland Under Different Uses In Qinghai-Tibet Plateau, Tao Li, Youmin Gan, Lei Ji, Shujing Yang, Zhongqi Song

IGC Proceedings (1977-2023)

In recent years, with the temperature rising on the Qinghai-Tibet Plateau, studies have shown that (Shaoqing Wang et al. 1999; Yuchun Qi et al. 2003) the plateau permafrost has great potential for emissions of greenhouse gases such as carbon, nitrogen, because of the remarkable permafrost thermal sensitivity. The Qinghai-Tibet Plateau is a special geographical and ecological unit, which has an important role in global climate change. The study of soil carbon storage of grassland ecosystems in the Qinghai-Tibet Plateau and its distribution characteristics allow the evaluation of different land management. The carbon cycle response and feedback effects of …

The Effects Of Management And Vegetation On Soil Carbon Stocks In Temperate Australian Grazing Systems, Warwick B. Badgery, Helen P. King, Aaron Simmons, Brian Murphy, Andrew Rawson, Elizabeth Warden

IGC Proceedings (1977-2023)

The natural spatial variability in soil organic carbon (SOC) found under perennial pasture systems can make it difficult to determine differences between contrasting agricultural management practices. Pasture composition in large, extensively grazed paddocks can give an indication of pasture growth, utilisation and fertility that influence SOC and are a result of management over the longer-term. This paper examines SOC stocks on the central and southern tablelands of NSW, Australia (average rainfall from 615 to 915 mm and average annual temperature from 10.6 to 15.6°C) at three scales (regional, between similar sites and within site) to determine the influence of management, …

Effects Of Enclosure On Biomass, Carbon, Nutrient Storage And Allocation For Seriphidium Transiliense In A Sagebrush Desert Grassland, Zheng Wei

IGC Proceedings (1977-2023)

We hypothesized that Seriphidium transiliense in a sagebrush desert grassland could improve the storage of biomass carbon and nutrient after 3 years of enclosure. Also, we expect distinctive allocation strategies of nutrient, carbon and biomass partitioning into root (R), root crown (RC), reproductive shoot (RS) and vegetative shoot (VS) plant characteristics or modules. Therefore, the storage and allocation pattern of biomass, carbon and nutrients (N, P, K, Ca and Mg) in different modules were monitored during September and October, from 2009 to 2011. The results showed that the P content of root, the N content of reproductive shoot, the Ca …

Long-Term Field Experiment For Monitoring Soil Carbon Content In Japanese Grasslands: Initial Data From 2010 To 2012, Shoji Matsuura, Hiroshi Hibino, Reiko Kazama, Hiroyuki Sasaki, Masayuki Hojito

IGC Proceedings (1977-2023)

A long-term field experiment for monitoring soil carbon content in Japanese grasslands started in 2010 to investigate the changes in soil carbon content and the effect of composted livestock manure application. We established grassland plots with 3 levels of manure application treatment at 10 sites. Bulk density values in many sites had wide inter-replicate and inter-annual variability. It is reasonable to suppose that the variability in the bulk density reflect spatial variability of physical properties within the grasslands because the annual trends of the bulk density values were not consistent. Organic carbon concentration tended to increase yearly in the surface …