Plant Biology Commons^™

Assessment Of Rangeland Condition In A Dryland System Using Uav-Based Multispectral Imagery, V. Amputu, K. Tielbörger, N. Knox

IGC Proceedings (1977-2023)

Dry savannahs are water-limited and under increasing anthropogenic pressure. Thus, considering climate change and the unprecedented pace and scale of rangeland deterioration, we need methods for assessing the status of such rangelands that are easy to apply, yield reliable and repeatable results that can be applied over large spatial scales. Global and local scale monitoring of rangelands through satellite data and labour-intensive field measurements respectively, are limited in accurately assessing the spatiotemporal heterogeneity of vegetation dynamics to provide crucial information that detects degradation in its early stages. Fortunately, newly emerging techniques such as unmanned aerial vehicles (UAVs), associated miniaturized sensors …

An Integrated Framework To Study Ecological Tipping Points In Social-Ecological Systems, F. A. Männer, L.-M. Schwarz, D. A. Menestrey-Schwieger, V. Amputu, M. C. Bilton, K. Brinkmann, G. Dressler, N. Hamunyela, H. Heita, S. Heshmati, S. Liehr, M. Mbidzo, F. Munyebvu-Chambara, W. C. Nesongano, M. Rauchecker, A. Sandhage-Hofmann, K. Tielbörger, K. Zimmer, A. Linstädter

IGC Proceedings (1977-2023)

Sudden regime shifts or tipping points pose a major threat to various ecosystems and people's livelihoods worldwide. However, tipping points are still hard to predict and often occur without warning. To avoid dramatic social-ecological consequences, it is crucial to understand tipping point behaviour and to identify early warning indicators. Previous studies have hardly implemented an integrated social-ecological approach, which has led to a fragmented understanding and oversimplification of tipping point phenomena. Against this background, we present a systemic research framework that harmonizes ecological and social perspectives to gain a mechanistic understanding of tipping point behaviour. We utilize a social-ecological systems …

An Integrated Assessment And Management Optimization System For Grazinglands, D. Toledo, J. E. Herrick, S. Goslee, M. Sanderson

IGC Proceedings (1977-2023)

Rangelands and pasturelands are often assessed using different methodologies. The Interpreting Indicators of Rangeland Health and Pasture Condition Scoring methodologies, two techniques used widely across the USA, were developed for rangelands and pasturelands respectively. These two grazingland assessment techniques were determined to be complementary and if integrated could provide an optimized approach to measure grazinglands without regards to specific use (i.e. range or pasture). We present an improved grazingland assessment protocol that merges indicators and attributes from Interpreting Indicators of Rangeland Health and Pasture Condition Scoring methodologies. This Integrated Grazingland Assessment (IGA) approach allows evaluators to assess site conditions and …

Transforming Science Into Practice, Janice Jiggins

IGC Proceedings (1977-2023)

The space for action that might move agricultural systems toward sustainability is narrowing. In so far as increasing dis-order in agroecosystems and food systems is caused by human agency, then remedial action must take account of cognition. This article argues that an understanding of cognitive processes is essential, as the foundation for participatory R, D & E that builds platforms of cooperation, binding actors into communities of learning that are trasnforming both science and practice.

Technology Transfer And Education Training And Extension In Grassland Farming, K. G. Rickert

IGC Proceedings (1977-2023)

Stakeholders in grassland farming, including farmers, rural communities, urban consumers, politicians, educators, and service agencies, widely agree that the goal for grassland farming is the triple bottom line: farming systems that are ecologically sustainable, profitable and socially acceptable. This paper considers how extension and training might contribute to that worthy goal by encouraging practitioners to better manage their management environment. The notion of a management environment refers to a holistic consideration of those factors that impact on farmers, farm advisors or educators, that subset of grassland farming ‘practitioners’ within the wider range of stakeholders.

The difficulty faced by these practitioners …

Gis-Based Forage Species Adaptation Mapping, David B. Hannaway, C. Daly, W. Gibson, G. Taylor, J. P. Bolte, I. Sriprisan, T. Griggs

IGC Proceedings (1977-2023)

Selecting forage crops adapted to the climatic and edaphic conditions of specific locations is essential for economic sustainability and environmental protection. Yet, currently, proper selection is difficult due to the absence of advanced selection tools. Significant improvements are being made in the process through Geographic Information System (GIS)-based mapping. Climate and soil GIS layers are being matched with forage characteristics through rules describing species tolerances. Better matching will reduce economic risks and environmental hazards associated with sub-optimal crop selection and subsequent performance. Once developed, these forage crop selection strategies and tools can be adapted for use with other crops. A …

On Farm Riparian Grazing Demonstration, J. T. Green Jr., M. H. Poore, S. P. Morgan

IGC Proceedings (1977-2023)

Two farm demonstrations were designed to show effects of periodic grazing of riparian areas. Sites were monitored for vegetative cover, degree of treading or hoof prints and dung deposition within three m of stream edge following grazing by beef cattle. A fenced enclosure was established along a 350 m stream reach on Farm-1, and eleven permanent stations were monitored following six graze periods over 12-months. Farm-2 involved grazing of two 0.13 ha paddocks, each of which contained a 22 m stream reach. On Farm-1 the cover improved following riparian exclusion, and evidence of treading in the 11 stations declined following …

Water Use Characteristics Of Weeds: A Global Review, Best Practices, And Future Directions, Mandeep Singh, Meetpal Singh Kukal, Suat Irmak, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Weeds usually penalize crop yields by competing for resources, such as water, light, nutrients, and space. Most of the studies on the crop-weed competition domain are limited to assessing crop-yield losses due to weed pressure and other crop-weed interactions, overlooking the significant uptake of soil-water by weeds that exacerbates global water constraints and threatens the productivity and profitability. The objective of this review was to synthesize globally available quantitative data on weed water use (WU) sourced from 23 peer-reviewed publications (filtered from 233 publications via a multi-step protocol of inclusion criteria) with experimental investigations across space (3 continents), time (1927–2018), …

Grassland Landscape Design: Working With Land-Managers, C. J. Pearson, R. K. Mann, I. G. Mann

IGC Proceedings (1977-2023)

We are entering an era of landscape design in order to simultaneously tackle largescale issues such as salinity and rising water tables, whole-farm profitability and the maintenance or enhancement of rural communities. In Australia, an important element of landscape design will be the reintroduction or broadening of the base of perennial grasses within farm systems. The goal of this project was to accelerate awareness and adoption of perennial grasses in a large but ecologically-specific area, namely the already-cleared steep uplands in the high rainfall recharge areas of the Murray-Darling Basin. We used a participatory model, in which land-managers made monthly …

Results With Methods For Measuring Herbage Mass In Situ, G. Nagy, I. Vinczeffy, K. Petõ

IGC Proceedings (1977-2023)

Two indirect methods for estimating herbage mass in situ were investigated in a research programme. Electric capacitance and spectral reflectance measurements were made and estimated values were compared with cut herbage mass results. Vegetation indexes (VI) measured by spectroradiometer showed a high correlation with fresh herbage mass, but there was no correlation observed between VI and dry matter results. Equations installed in electric capacitance meter were not feasible for Hungarian conditions. The change of electric capacitance in the sward (CMR) gave no correlation with cut DM yields. The investigated indirect methods are not suitable for research or production use yet.

Application Of Municipal Biosolids To Bahiagrass Pasture: Trace Metals In Harvested Forage, R. M. Muchovej, J. E. Rechcigl

IGC Proceedings (1977-2023)

Municipal biosolids (sewage sludge) are the by-products of wastewater treatment plants and their production, worldwide, has steadily increased over the past years. Florida is one of the fastest growing states in the USA. Biosolids are readily and increasingly available throughout the state. Pasture fertilization has been shown to increase biomass and quality of bahiagrass (Paspalum notatum Flugge) dramatically in Florida sandy soils. Nevertheless, with low cattle prices, ranchers are forced to reduce fertilizers inputs. Biosolids contain considerable amounts of nutrients, especially nitrogen (N), phosphorus (P), sulphur (S), calcium (Ca), and micronutrients, and are inexpensive when compared with commercial fertilizers. …

Rangelands Vegetation Mapping At Species Composition Level Using The Spicla Method: SDm Based PiXel ClaSsification And Fuzzy Accuracy. A New Approach Of Map Making, A. G. Toxopeus, C. A. J. M. De Bie, E. H. Kloosterman, J. K. Mbaluka, P. K. Mwangi, L. G. J. Boerboom

IGC Proceedings (1977-2023)

Vegetation maps have been made since centuries. The vegetation cover was represented as homogeneous mapping units (polygons), representing different vegetation types, where each type consists a combination of different plant species (floristic composition). More recent, with the use of satellite imagery, the polygons have been replaced by pixels with similar content as the polygon maps. In both approaches, field-observations were linked to the mapping units (polygons or pixels) often resulting in a complex of different vegetation types per mapping unit. In our new approach field data (sample points) on presence and abundance of individual grass species are spatially extrapolated based …

Adoption And Influence: Industry Evaluation Of The GrassgroTm Decision Support Tool, E. M. Salmon, A. D. Moore

IGC Proceedings (1977-2023)

The GrassGro Decision Support tool (DS tool) (Donnelly and Moore, 1999) was released for commercial use in Australia with a training package in late 1997. An assessment of its adoption was made by a survey of 53 registered users in March 1999. An evaluation of the software and training package was made at training workshops by 92 users between 1997 and December 1999. The response rates to the survey and the evaluation were 62% and 82% respectively. Seventy six percent of survey respondents had analysed at least one problem with GrassGro and 27% had applied GrassGro to five or more …

Digestibility Estimates Based On A Grass Growth Model Are Distributed Via Internet To Finnish Farmers, Marketta Rinne, J. Nousiainen, I. Mattila, H. Nikander, P. Huhtanen

IGC Proceedings (1977-2023)

Optimising the harvesting time of grass in primary growth is difficult under Finnish climatic conditions, because the digestibility of grass decreases on average by 0.5 percentage units daily. We constructed a model based on cumulative temperature and geographical location which estimates the digestibility of grass. This model is used to produce estimates utilising real time weather information. The estimates are presented as a map, which is revised daily. Farmers have free access to the maps via Internet.

Kentucky Alfalfa Conference: A Team Approach To Alfalfa Education And Technology Transfer, Garry D. Lacefield, Monroe Rasnake, Christi L. Forsythe, Jimmy C. Henning, Bill Talley

IGC Proceedings (1977-2023)

Alfalfa has played an important role in providing farmers of Kentucky with a high yielding, high quality, persistent forage legume for many years. In 1980, a group of individuals under the leadership of University of Kentucky Forage Extension Specialists organized and implemented the first statewide educational event on alfalfa. This initial meeting gave rise to the Kentucky Alfalfa Conference that celebrated it’s twentieth anniversary in February 2000. This annual event has been co-sponsored by the University of Kentucky, Kentucky Forage and Grassland Council, along with other state and national groups including Certified Alfalfa Seed Council, Kentucky Department of Agriculture, Kentucky …

Developing A National Alfalfa Information System, David B. Hannaway, K. J. Hannaway, P. Sohn, S. Griffith, B. E. Avery, E. Nowick, W. F. Wedin, L. R. Vough, S. C. Bosworth, Garry D. Lacefield, Gary E. Bates, D. Undersander, N. P. Martin, J. Caddel, G. L. Kilgore, S. B. Orloff, A. M. Gray, R. Ditterline, T. Griggs, D. H. Putnam, M. J. Ottman

IGC Proceedings (1977-2023)

Using state-of-the-art telecommunication technologies, this project is developing a comprehensive knowledge resource for alfalfa (Medicago sativa L.); the National Alfalfa Information System (NAIS). This project will serve as an improved model for Extension educational programs. Alfalfa is the most important forage crop in the USA and grown worldwide for feeding millions of livestock and in many cropping systems. As a legume, it is important in sustaining the environment and the productivity of agriculture. Information needs are present in every state and internationally. The NAIS is being developed through national and international cooperation, putting the best science-based alfalfa information and …

Map Based Www Tool For Recommending Forage Species, M. H. Hall, D. A. Miller, J. H. Cherney

IGC Proceedings (1977-2023)

Selecting the “best” forage species or species mixture requires a knowledge and understanding of the consuming animal, soil characteristics, and forage species. The multivariate nature of the problem presents challenges to those interested in solving the practical problem of maximizing available resources. Earlier work at Cornell University resulted in a WWW-based interface that allowed the user to provide a soil type or zip code and additional management factors to initiate the species selection. This approach relies on either user knowledge of soil series or an implied relationship between zip code and soil series that may often be wrong. To improve …

Remote Sensing Application To Grassland Monitoring, Z. B. Nan

IGC Proceedings (1977-2023)

Application of remote sensing to the management of grassland resources, the role this plays in developing sustainable grassland farming systems and opportunities for further development are outlined. Use of remote sensing technologies in grassland monitoring has a history of more than 30 years. Both fine- and coarse-grained remote sensing techniques are used to monitor and study grasslands. Fine-grained techniques are used to study landscape scale processes through the use of sensors providing spatial resolution of a few meters, whereas coarse-grained techniques are used to study catchment scale areas, and even entire biomes, using satellite-based sensors with a spatial resolution of …

Modelling Grassland Ecosystems, J. H. M. Thornley

IGC Proceedings (1977-2023)

In this contribution a view of the promise and difficulties of modelling grassland is given. This is largely centred around work with a grassland ecosystem simulator known as the Hurley Pasture Model.

A brief introduction sets forth possible reasons for building a large ecosystem model, and stresses the importance of modelling objectives. It is suggested that a model is de rigeur for any research programme which aims to take a firm grasp of the complex responses of grassland. Mechanistic models are required to provide the understanding needed for intelligent and flexible management of grassland, whatever the prevailing environmental or economic …

Estimating Herbage Mass In Stargrass (Cynodon Nlenfuensis Var Nlenfuensis) Using Sward Surface Height And The Rising Plate Meter, D. E. Oliveira, S. R. Medeiros, L. J. M. Aroeira, L. G. Barioni, D. P. D. Lanna

IGC Proceedings (1977-2023)

Estimation of herbage mass is necessary both in research and farm management. Methods for such estimations should be inexpensive, rapid and reliable. Since estimations through hand clipping are time consuming, a range of indirect methods have been developed and tested in the literature. This study had the aim of comparing precision of two indirect methods, sward surface height (SSH) and the rising plate meter (RPM), to estimate herbage mass in stargrass pastures (Cynodon nlenfuensis var. nlenfuensis). Pre-grazing measurements of SSH and RPM readings were taken and compared with the paddock herbage mass. RPM readings were converted into centimeters. Average …

Management-Intensive Grazing Impacts On Total Escherichia Coli, E. Coli O157: H7, And Antibiotic Resistance Genes In A Riparian Stream, Laura M. Rubeck, James E. Wells, Kathy Hanford, Lisa M. Durso, Walter H. Schacht, Elaine D. Berry

Department of Agronomy and Horticulture: Faculty Publications

The impacts of management-intensive grazing (MIG) of cattle on concentrations of total Escherichia coli, total suspended solids (TSS), and nitrate-nitrite nitrogen (NO₃+NO₂-N), and occurrence of E. coli O157:H7 and selected antibiotic resistance genes (ARGs) in stream water and/or sediments were evaluated. Cattle were grazed for twoweek periods in May in each of three years. Overall, grazing increased total E. coli in downstream water by 0.89 log10 MPN/100 mL (p < 0.0001), and downstream total E. coli concentrations were higher than upstream over all sampling intervals. Downstream TSS levels also increased (p ≤ 0.0294) during grazing. In contrast, there was …

The Analysis Of Results From Paired Paddock Comparisons, David R. Kemp, P. M. Dowling, D. L. Michalk, G. Millar

IGC Proceedings (1977-2023)

Paired-paddock comparisons are a common way of evaluating new grassland practices at a scale more relevant to farmers. They are also being used to replace or augment designed experiments and can be the only source of information available on a practice. However, it is often uncertain if the differences between paddocks are significant. Importantly, a current trend among funding organisations is to support paddock comparisons. The need for valid procedures to compare unreplicated treatments is increasingly urgent. It is suggested that a range of tools be used to infer statistical significance from using typical error values from related studies or …

Length And Width To Estimate Dry Mass Of Panicum Maximum Cv. Tanzânia Leaves, L. G. Barioni, P. M. Santos, A. Coldebella, M. Corsi

IGC Proceedings (1977-2023)

An analysis of the relationship of leaf length (LL) and leaf width (LW) with leaf dry weight (LDW) in Panicum maximum was carried out with the objective of improving estimations of tissue flow in that plant. Data was collected in a mob grazing experiment with 28 days grazing interval sampled the day before grazing in 9 grazing cycles. Regression analysis revealed highly significant effect (P < 0.001) of both LL and LW on LDW. A lack of fit test gave strong evidence of non-linear relationship of LDW with LL (p < 0.05), fitting the model 1 0 LDW = β₀LL^β₁ , while LW presented a linear relation with LDW. LL was a better predictor of LDW than LW. LL solely or in combination with LW produced equations with …

Bioeconomic Model For Decision-Making On Fattening Beef-Cattle, G. Ferreira, O. Cardozo, J. M. Soares De Lima

IGC Proceedings (1977-2023)

Profitability and competitiveness of agricultural systems it is closely related with the technology used. Economic and financial appraisal of investments on pasture improvements, facilities, feed and management plans, etc. are often required in order to make decisions. A bio-economic simulation model was developed in order to support decision making on beef-cattle grazing fattening. The aim of the model is to show the relationship between the technological alternative analysed in physical terms as well as financial and economic. By this way it is possible to asset and relate the bio-economic impact of the different animal and pasture management alternative technologies. Results …

Sequential Injection Analysis: A Powerful Tool For Routine Soil And Plant Laboratories, A. R. A. Nogueira, F. V. Silva, M. Y. Kamogawa, G. B. Souza, L. F. M. Ferraz

IGC Proceedings (1977-2023)

Sequential injection analysis (SIA) present attractive characteristics for analyses in large scale. In SIA the analytical determination can be performed automatically reducing the number of steps usually involved in a chemical analysis. In order to demonstrate the advantages found in the implementation of a SIA procedure in a laboratory dedicated to routine analyze, the determination of volatile nitrogen in silage and soil samples has been performed. The nitrogen content was determined after NH₃ on-line separation in alkaline conditions by using a gaseous diffusion or a pervaporation unit for liquid-liquid separation. An ammonium tubular selective electrode detector was used for …

A Chance-Constrained Linear Model For Beef Policy Analysis, Claudio F. Machado, S. T. Morris, C. Dake, A. Macdonald, I. M. Brookes, F. Di Croce, F. Gonzalez, N. J. Auza

IGC Proceedings (1977-2023)

A simple linear model to evaluate different bull beef policies (BBP) by incorporating the stochastic nature of pasture yield from a database with separate chance constraints (ChC) was developed. A 100 ha farm was used, and the model was run with five different BBP and set to different levels of pasture yield risk to maximise production.ha^-1.year^-1. Summer was the most risky season, and the optimum mix of policies changed at different levels of risk. Chance constraint represents an interesting and simple alternative to include pasture variation into a linear model.

Mapping Nitrogen Fixing Shrubs In Dry Unimproved Tussock Grassland, C. C. Boswell, W. L. Lowther, P. D. Espie

IGC Proceedings (1977-2023)

Global Positioning System (GPS) was used to both map the positions of individual nitrogen-fixing shrub plants and record individual plant height and breadth dimensions, within a small catchment of dry sub-humid unimproved short tussock grassland. The distributions of different species of shrubs varied with different landscape units within the catchment. The information will provide the base data for a first approximation of the role of the shrubs in the nitrogen balance of the ecosystem, which is pivotal to the sustainability of pastoral farming in the tussock grasslands.

Repeated Measurement Analyses Of Forages In Cropping Systems, A. R. De Freitas, O. Primavesi, L. De A. Corrêa, A. C. Primavesi, E. B. Pott, A. Dos S. Mascioli

IGC Proceedings (1977-2023)

Repeated measurements (RM) are common in forage experiments. The data used in this study were accumulated ammonia losses by volatilization (N) and dry matter production (DM) of Cynodon dactylon cv. Coastcross pasture from an experiment in blocks with five levels of urea: 0, 25, 50, 100 and 200 kg of N ha^-1, applied in five periods (cuttings). For N, RM were the averages of cuttings and nine days of observation. The F test for the hypothesis of no effect for Period and Level x Period interaction (DM) and for Days and Level x Days interaction was not affected …

Farmwi$E: A Flexible Decision Support Tool For Grazing Systems Management, A. D. Moore

IGC Proceedings (1977-2023)

CSIRO's new FarmWi$e decision support tool provides a framework that permits pasture-livestock systems and management policies of any level of complexity to be simulated. An underlying "modelling protocol" permits other simulation models to be added, further extending its domain of applicability. Management policies are specified in FarmWi$e by means of rules that govern when, whether and how management events take place. An example of the use of FarmWi$e to study lamb production is given.

Sward Height; Visual Estimate Compared With Plate Meter Height, W. B. Bryan, E. C. Prigge, E. L. Nestor, O. J. Gekara, M. A. Schettini

IGC Proceedings (1977-2023)

Sward height (SH) is widely used in pasture research and farm practice to evaluate pasture conditions. Visual estimates can take less time than actual measurements. This study compared visually estimated SH, of continuously grazed cool-season permanent pasture with plate meter height. Weekly estimates, by five people, were made on 12, 0.75 to 1 ha fields, grazed at two intensities. Paired data (visual estimate and plate meter height) were subjected to variance and covariance analyses and prediction equations were developed. Average visual height accounted for 86% of the variability in plate meter height. Inclusion of other sources of variability in the …