Agricultural Science Commons^™

The Effect Of Early And Delayed Spring Grazing On The Milk Production, Grazing Management And Grass Intake Of Dairy Cows, E. Kennedy, M. O'Donovan, J. P. Murphy, L. Delaby, F. P. O'Mara

IGC Proceedings (1977-2023)

Earlier access to pasture can increase the overall proportion of grazed grass in the diet of the spring calving dairy cow. Further benefits can also be achieved from early turnout, including improved animal production, increased sward utilisation and enhanced sward quality (O’Donovan et al., 2004). The objective of this study was to compare the effect of initial spring grazing date and stocking rate on the performance of spring calving dairy cows.

Intake Characteristics Of Diploid And Tetraploid Perennial Ryegrass Varieties When Grazed By Simmental X Holstein Yearling Heifers Under Rotational Stocking Management, R. J. Orr, J. E. Cook, K. L. Young, R. A. Champion, A. J. Rook

IGC Proceedings (1977-2023)

Orr et al. (2003) measured large differences in dry matter (DM) intake rate between 15 intermediate-heading perennial ryegrass varieties when they were continuously stocked with sheep and subsequently explored the extent to which, for 5 of these varieties, these differences could be explained by chemical and morphological traits (Orr et al., 2004a) which could be targeted in grass breeding programmes. Here, four of the 15 varieties, which within ploidy had low or high intake characteristics when grazed by sheep, were rotationally stocked with cattle and intake and sward factors were measured.

Optimising Financial Return From Grazing In Temperate Pastures, P. Dillon, J. R. Roche, L. Shalloo, B. Horan

IGC Proceedings (1977-2023)

Key Points

1. The increased interest in pasture-based systems of milk production in recent years has been largely generated through lower product prices and rising costs of production.

2. Pasture based systems of milk production decrease unit production costs, through lower feed and labour expenses, and reduced capital investment.

3. Systems utilising grazed pasture will be optimised in regions where pasture production potential is high, variability in seasonal pasture supply and quality is low, manufacturing milk accounts for a large proportion of total production, and where large areas of land are available at relatively low cost.

4. Pasture based systems may allow greater global …

   ---

   Go to article

Challenges And Opportunities For Animal Production From Temperate Pastures, D. A. Clark

IGC Proceedings (1977-2023)

Key points

1. Temperate pastures offer a major opportunity to reduce the feed costs associated with ruminant production.

2. Pastures offer unique opportunities for producing high value components in feedstuffs that are beneficial to human health.

3. The increased use of pasture will not automatically lead to improved environmental outcomes – difficult challenges exist in reducing nitrogen and greenhouse gas pollution.

4. Grazed pasture systems offer advantages in animal welfare, provided management avoids the problems associated with climatic extremes, and the toxins associated with some pastures.

5. To remain competitive with total mixed ration systems, and environmentally acceptable, pastures with higher intake characteristics that allow …

   ---

   Go to article

Decision Support For Temperate Grasslands: Challenges And Pitfalls, J. R. Donnelly, L. Salmon, R. D. H. Cohen, Zl. Liu, Xp. Xin

IGC Proceedings (1977-2023)

Key points

1. Successful adoption of decision support tools (DS tools) to address grassland management issues requires careful attention in design to ensure ease-of-use, accuracy in prediction and the flexibility to simulate actual practices.

2. DS tools must handle spatial variability and where possible include facilities for automatic sourcing of essential information for initialisation.

3. Advances in the development of DS tools will depend on resolution of scientific issues in grassland biology including investment in dedicated experiments to determine parameter values for model equations.

4. The use of mechanistic models, the integration of remote sensing technology and cooperation between research groups to develop modular …

   ---

   Go to article

Modelling Of Herbage Intake And Milk Production By Grazing Dairy Cows, Rémy Delagarde, M. O'Donovan

IGC Proceedings (1977-2023)

Key-points

1. Models predicting intake and performance of grazing ruminants from animal, sward, grazing and supplements characteristics are rare, but they are now included in several decision support systems (DSS).

2. An evaluation of the performance and accuracy of published models are rarely undertaken by their authors, but this is proposed in this paper.

3. There is still a need for experimental research but also for the development of generic and dynamic models to predict intake and performance over a wide range of grazing conditions.

Grass Growth Modelling: To Increase Understanding And Aid Decision Making On-Farm, P. D. Barrett, A. S. Laidlaw

IGC Proceedings (1977-2023)

Key points

1. Crop and grass growth models have been developed over the last 50 years, or so, but general appreciation of their benefits and potential has been recognised only relatively recently. The most popular application of grass growth models has traditionally been for knowledge understanding.

2. There is growing awareness of the potential of models in decision support systems (DSS) applications to aid pasture management and grassland budgeting on dairy farms.

3. Although some models have been developed for DSS, their widespread uptake in industry has been slow; challenges still exist which need to be addressed in order to improve their precision …

   ---

   Go to article

Genetic Characteristics Required In Dairy And Beef Cattle For Temperate Grazing Systems, F. Buckley, C. Holmes, M. G. Keane

IGC Proceedings (1977-2023)

Key points

1. Only about 10% of the world’s milk is produced from grazing systems. Consequently the majority of dairy cattle have not been selected under grazing, nor on seasonal systems. This is not true for beef cattle, for which the majority, especially the dams, are managed under seasonal grazing systems.

2. In grazing systems daily feed intake is limited to lower levels than are achievable on concentrate plus conserved forage rations. Consequently, cows most suited to grazing environments are likely to have a lower genetic potential for milk production than cows selected in high concentrate systems, to minimise their relative energy …

   ---

   Go to article

New Insights Into The Nutritional Value Of Grass, D. H. Rearte

IGC Proceedings (1977-2023)

Key points

1. The rumen environment in cattle grazing high quality forage is different to that reported for cattle fed indoors with diets based on processed feedstuffs.
2. Temperate pasture is an excellent source of nutrients for ruminants but a high energy:protein imbalance can occur when it is offered at the stage of optimal digestion.
3. Beef and milk produced on grass in temperate regions have a composition with nutritional advantages over beef or milk produced in indoor systems based on concentrate.
4. Increasing water soluble carbohydrate content of grasses would diminish environmental contamination by reducing the excretion of urea through the urine.
5. Increasing …

Plant And Sward Characteristics To Achieve High Intake In Ruminants, W. J. Wales, C. R. Stockdale, P. T. Doyle

IGC Proceedings (1977-2023)

Key points

1. Intake is affected by complex interactions between signals from the digestive tract, intermediary metabolism and energy supply, and behavioural signals associated with learned behaviours or sensory signals.
2. The ideal sward needs to have characteristics that are similar to total mixed rations to achieve high intake and animal performance.
3. Genetic manipulation of plants may offer an accelerated rate of plant improvement, but benefits need to be demonstrated in a systems context.

Overview Of Animal Production From Pastures In Ireland, M. J. Drennan, A. F. Carson, S. Crosse

IGC Proceedings (1977-2023)

Key points

The importance of grassland to agriculture in Ireland is indicated by the fact that:

1. Sixty percent of agricultural output is from grassland as cattle, milk and sheep products.
2. Over 90% of the total farmed area is in grass.
3. Livestock are almost entirely dependent on grazed grass for 200 to 235 days of the year.
4. Grass conserved as silage is the main source of fodder in winter.
5. To improve competitiveness changes are continuously taking place, which include:

• increased suckler herd size and a movement to late maturing continental cattle breeds;
• movement in the dairy herd towards Holstein with increased …

A Diagnostic Framework For Reengineering Soil: Potential Strategies To Manage Combinations Of Soil Constraints For Sands And Texture Contrast Soils, Gaus Azam, Stephen Davies

Natural resources published reports

This report is an output of project DAW1902-003RTX ‘Reengineering soils to improve the access of crop root systems to water and nutrients stored in the subsoil’, supported by a co-investment between the Department of Primary Industries and Regional Development (DPIRD) and the Grains Research and Development Corporation (GRDC).

Key messages:

• Existing soil amelioration options can generate substantial yield responses. However, further yield gain is possible with further improvement in soil amelioration strategies.

• Mapping of soil constraints and potential yield gaps using the water use efficiency achieved from a pilot reengineering experiment has identified a significant yield gap attributed …

Comparisons Of Small Unmanned Aircraft Systems And Agro-Terrestrial Surveys: Techniques To Determine Field Elevation Surfaces For Improved Crop And Water Management., Richard A. Pickett Jr

Student Theses and Dissertations

Row crop agriculture in Arkansas relies predominantly on groundwater resources for irrigation. This places great demand on the Mississippi River Valley Alluvial Aquifer (MRVAA), which is in a current state of decline. The Eastern Arkansas region produces commodity crops including soybeans, rice, corn, cotton, and peanuts, all of which utilize irrigation for optimal productivity. Conservation practices that reduce groundwater use include precision land leveling, multiple inlet rice irrigation, and computerized hole size selection for furrow irrigation. To collect elevation data to irrigate efficiently, these practices require precision agriculture technology, more specifically Real-Time Kinematic–Global Navigation Satellite Systems (RTK-GNSS). As RTK-GNSS technologies …

Automation Of Irrigation To Improve Outcomes Of Agronomic Crops: On-Farm And Modeling Demonstrations, Thais Murias Jardim

Student Theses and Dissertations

Automated irrigation systems and new management practices may help address aquifer depletion, labor shortages, and irrigation management challenges. This study evaluated the impact of various automated irrigation systems on commercial farms that produce maize, rice, and soybean. It also modeled how Early Cascade Rice Irrigation Shutoff (ECIS) performs under a range of field conditions. Growers observed various benefits of using automated systems other than irrigation savings or yield increase. Timers and remote shutoff are the most practical and beneficial options for growers willing to adopt some level of automation. ECIS modeling estimates showed that applied irrigation and runoff decreased as …

Pearl Millet Response To Drought: A Review, Nikee Shrestha, Hao Hu, Kumar Shrestha, Andrew N. Doust

Department of Agronomy and Horticulture: Faculty Publications

The C4 grass pearl millet is one of the most drought tolerant cereals and is primarily grown in marginal areas where annual rainfall is low and intermittent. It was domesticated in sub-Saharan Africa, and several studies have found that it uses a combination of morphological and physiological traits to successfully resist drought. This review explores the short term and long-term responses of pearl millet that enables it to either tolerate, avoid, escape, or recover from drought stress. The response to short term drought reveals fine tuning of osmotic adjustment, stomatal conductance, and ROS scavenging ability, along with ABA and ethylene …

Improving Phosphorus Acquisition Efficiency Through Modification Of Root Growth Responses To Phosphate Starvation In Legumes, Zhijian Chen, Linjie Wang, Juan Andres Cardoso, Shengnan Zhu, Guodao Liu, Idupulapati M. Rao, Yan Lin

All Peer-Reviewed Publications

Phosphorus (P) is one of the essential macronutrients for plant growth and development, and it is an integral part of the major organic components, including nucleic acids, proteins and phospholipids. Although total P is abundant in most soils, a large amount of P is not easily absorbed by plants. Inorganic phosphate (Pi) is the plant-available P, which is generally immobile and of low availability in soils. Hence, Pi starvation is a major constraint limiting plant growth and productivity. Enhancing plant P efficiency can be achieved by improving P acquisition efficiency (PAE) through modification of morpho-physiological and biochemical alteration in root …

Assessment Of Variable Rate Nitrogen Application On Rice Cultivars Using Remote Sensing, Rush Matthew Evans

Student Theses and Dissertations

Application of the right time and amount of fertilizer N is challenging in rice fertilization because crop N supply is highly variable in the field. Research plots were established at four research plot fields and one commercial field in Arkansas. Independent variables included six nitrogen (N) application rates (0, 67, 101, 134.5, 168, and 202 kg N ha-1), multiple rice cultivars, and five locations. The response variable was 24 vegetative indices values using high spatio-temporal multispectral and thermal imagery obtained from an Unmanned Aerial Vehicle (UAV). The 134 and 168 kg N ha-1 rates were identified as the control group …

Evaluation Of Polyacrylamide (Pam) Effects On Irrigation Efficiency, Soil Conservation, And Water Quality In Midsouth Cotton Production, Brittany D. Barnes

Student Theses and Dissertations

The polymer, polyacrylamide (PAM), is a high molecular weight, chemical anionic polymer that is prescribed and used for irrigation improvement in row crops primarily in the United States. A field research study was conducted in 2014, 2015 and 2016 in Northeast Arkansas to evaluate how addition of PAM in furrow irrigation affected soil erosion, water infiltration, movement of nutrients and sediments, and crop yields in cotton (Gossypium hirsutum). Overall results from the study were mixed. Sediment loss was similar among treatments. Irrigation advancement rates were not significantly different. No differences in crop yield were observed associated with PAM. Differences in …

Expression Of Malic Enzyme Reveals Subcellular Carbon Partitioning For Storage Reserve Production In Soybeans, Usda Agricultural Research Service, Donald Danforth Plant Science Center, Donald Danforth Plant Science Center, Thomas E. Clemente, Hanh T. Nguyen

Department of Agronomy and Horticulture: Faculty Publications

• Central metabolism produces amino and fatty acids for protein and lipids that establish seed value. Biosynthesis of storage reserves occurs in multiple organelles that exchange central intermediates including two essential metabolites, malate, and pyruvate that are linked by malic enzyme. Malic enzyme can be active in multiple subcellular compartments, partitioning carbon and reducing equivalents for anabolic and catabolic requirements. Prior studies based on isotopic labeling and steady-state metabolic flux analyses indicated malic enzyme provides carbon for fatty acid biosynthesis in plants, though genetic evidence confirming this role is lacking. We hypothesized that increasing malic enzyme flux would alter carbon partitioning …

  ---

  Go to article

Protecting Wa Crops Issue 27 - February 2023, Department Of Primary Industries And Regional Development, Western Australia

Protecting WA Crops

Protecting WA Crops Issue 27 - February 2023 contents:

• Glyphosate alternatives for summer and pre-seeding knockdown weed control
• Meet Crop Protection team member – Cindy Webster

Development And Testing Of An Iot Spectroscopic Nutrient Monitoring System For Use In Micro Indoor Smart Hydroponics, Joseph D. Stevens, David Murray, Dean A. Diepeveen, Danny Toohey

Horticulture Research Articles

Nutrient monitoring in Micro Indoor Smart Hydroponics (MISH) relies on measuring electrical conductivity or total dissolved solids to determine the amount of nutrients in a hydroponic solution. Neither method can distinguish concentrations of individual nutrients. This study presents the development and testing of a novel spectroscopic sensor system to monitor nitrogen changes in nutrient solutions for MISH systems. The design phase determined that using an inexpensive AS7265x Internet of Thing (IoT) sensor in a transflective spectroscopic application could effectively detect small fluctuations in nitrogen concentraation. Next, a novel transflective sensor apparatus was designed and constructed for use in a MISH …

Access And Use Of Consortium For E-Resources In Agriculture (Cera) By The Research Scholars And Post Graduate Students Of The Krc College Of Horticulture, Arabhavi, Uhs Bagalkot, Manjunath B. Hadimani Mr., Vinayaka M. Bankapur Dr.

Library Philosophy and Practice (e-journal)

In the electronic information age, consortiums are gaining more importance. The consortia movement has entered libraries and has received attention from the information-producing community. CeRA consortium is a tremendously great effort on the part of the Indian Council of Agricultural Research (ICAR) to propose single-window access to e-resources to State Agricultural Universities (SAU)/ICAR institutes all over India. CeRA subscribed to e-Resources and create/facilitate an e-environment and e-access culture for faculty, scientists, research scholars, and students in the National Agricultural Research and Education System. The current study attempts to understand the access and use of CeRA among the researchers and PG …

Grassland Productivity And Water Quality: A 21st Century Issue, David M. Nash, P. M. Haygarth

IGC Proceedings (1977-2023)

1. Irrigation and other changes to the hydrological cycle can increase soil and water salinity.
2. Primary salinisation is a natural process that affects much of Europe, Asia, Africa, the Americas and Australia. Secondary salinisation is caused by human activities such as irrigation and land clearing that mobilise salt stored in the soil.
3. The critical water contaminants exported from grasslands are nitrogen, phosphorus, potential pathogens and sediment.
4. The mechanisms responsible for diffuse pollution from grasslands and mitigation strategies are most effectively investigated using a ‘source-mobilisation-transport’ framework.
5. There is a lack of coherent interaction across discipline boundaries that links pollutant sources to impact. …

Water Resources, Agriculture And Pasture: Implications Of Growing Demand And Increasing Scarcity, M. W. Rosegrant, R. A. Valmonte-Santos, S. A. Cline, C. Ringler, W. Li

IGC Proceedings (1977-2023)

1. Water availability for irrigation is threatened in many regions by rapidly increasing demand for nonagricultural water uses in industry, households, and the environment. The scarcity of irrigation water will not only impact crop production, but also meat production, as much of the pasture used to feed livestock is irrigated.
2. Grassland is caught between two countervailing forces: a requirement for increasing meat demand that boosts the need for additional pasture to support livestock production, and rapidly increasing water scarcity that makes pasture irrigation uneconomical.
3. The most effective means of dealing with water scarcity is likely to be conserving water in existing …

Soil Quality Assessment And Management, M. G. Kibblewhite

IGC Proceedings (1977-2023)

1. Soil quality is related to the capacity of soil to deliver ecosystem services on a sustainable basis.
2. Effective management of soil within grasslands can deliver many benefits to mankind but poor management may cause loss of soil quality from erosion, loss of organic matter, physical deterioration etc.
3. Services are delivered from soil by biological processes. Soil quality depends on the form and condition of the soil habitat. Fixed factors (e.g. texture) are useful for assigning soil to types. Variable factors (e.g. organic carbon) can then be used to assess quality within soil types, by reference to percentiles of the distribution …

Soil Microbial Community: Understanding The Belowground Network For Sustainable Grassland Management, Y. G. Zhu, W. D. Kong, B. D. Chen, Z. B. Nan, P. Christie

IGC Proceedings (1977-2023)

1. In addition to the use of conventional methodologies in soil microbial research, molecular techniques are now being applied to gain insights into the soil microbial community;
2. Plant diversity can exert impacts on soil microbial diversity (through root activities and plant litter etc.), but may in itself be significantly altered by soil properties;
3. Soil microbial diversity largely determines the stability of soil ecosystems under biotic and abiotic perturbations.
4. Management of soil microbial diversity can only be achieved through better understanding their structures and functions.

Grasslands1 For Production And The Environment, David R. Kemp, David L. Michalk

IGC Proceedings (1977-2023)

1. To manage grasslands for production and enhanced environmental values requires a redefinition of the frameworks within which management decisions are made, and a tailoring of practices to suit the ways that farmers operate.
2. Improving the perenniality and permanence of grasslands usually leads to better environmental and production outcomes.
3. There is a case for a more conservative approach to utilising grasslands in order to sustain the functioning of local ecosystems and to improve water quality, nutrient and energy cycling and biodiversity.
4. A landscape rather than paddock focus is more appropriate for meeting current grassland management objectives. Grasslands can be triaged to …

The Potential Of Grassland And Associated Forages To Produce Fibre, Biomass, Energy Or Other Feedstocks For Non-Food And Other Sectors: New Uses For A Global Resource, M. F. Askew

IGC Proceedings (1977-2023)

1. In developed countries increased areas of land will become available for non-food production. Recent reforms of the Common Agricultural Policy will further intensify this trend in Europe.
2. There is potential for grassland and associated species to contribute to large tonnage markets of energy and bulk fibres, to the supply of fermentation products and to speciality markets, but processes and approaches to the market are not as yet developed.
3. There is potential for the establishment of Graminaceous species - specifically for non- food use. For European conditions particular attention is being given to Miscanthus sinensis (Miscanthus), Arundo donax (Giant Reed), Phalaris …

Grasses As Biofactories: Scoping Out The Opportunities, Nick Roberts, K. Richardson, G. Bryan, Christine R. Voisey, W. Mcnabb, T. Conner, M. Christey, R. Johnson

IGC Proceedings (1977-2023)

1. Plant biopharming is set to dominate commercial recombinant protein expression for specific proteins.
2. The choice of plant species depends on a multitude of factors and is determined on a case- by-case basis.
3. As a leaf based expression system grasses would have to compete predominantly with tobacco and alfalfa.
4. The grass-endophyte symbiosis offers a number of unique possibilities for biopharming.

Adoption Of Tropical Legume Technology Around The World: Analysis Of Success, H. M. Shelton, Steven Franzel, M. Peters

IGC Proceedings (1977-2023)

1. Examples of successful adoption of forage legumes are reported from all continents, where they delivered profitability and often provided multipurpose benefits to farmers.
2. Factors vital to successful adoption were: meeting the needs of farmers; building relevant partnerships; understanding the socio-economic context and skills of farmers; participatory involvement with rural communities; and long-term involvement of champions.
3. Organisation of seed supply, achieving scale-up and forming partnerships to implement adoption are key features.
4. Legumes remain an important but under-exploited resource for tropical farming systems. The alternative to legumes will be greater and more costly use of N-fertilisers and purchased protein concentrates.
5. The R&D …