Agricultural Science Commons^™

Morphological And Moisture Availability Controls Of The Leaf Area-To-Sapwood Area Ratio: Analysis Of Measurements On Australian Trees, Henrique Furstenau Togashi, Iain Colin Prentice, Bradley John Evans, David Ian Forrester, Paul Drake, Paul Feikema, Kim Brooksbank, Derek Eamus, Daniel Taylor

Natural Resources Research Articles

1. The leaf area-to-sapwood area ratio (LA:SA) is a key plant trait that links photosynthesis to transpiration. The pipe model theory states that the sapwood cross-sectional area of a stem or branch at any point should scale isometrically with the area of leaves distal to that point. Optimization theory further suggests that LA:SA should decrease toward drier climates. Although acclimation of LA:SA to climate has been reported within species, much less is known about the scaling of this trait with climate among species.
2. We compiled LA:SA measurements from 184 species of Australian evergreen angiosperm trees. The pipe model was …

Compost Carryover: Nitrogen Phosphorous And Ft-Ir Analysis Of Soil Organic Matter, Dave J. R. Olsen, Jeffrey B. Endelman, Astrid R. Jacobson, Jennifer R. Reeve

Plants, Soils, and Climate Faculty Publications

Compost plays a central role in organic soil fertility plans but is bulky and costly to apply. Determining compost carryover is therefore important for cost-effective soil fertility planning. This study investigated two aspects of nutritive carryover [nitrogen and phosphorus (P)], and an indicator of non-nutritive carryover [soil organic matter (SOM)] to determine the residual effect of a one-time compost application applied at four rates in a corn-squash rotation. Crop yield was measured as an integrated carryover indicator of nutritive and non-nutritive effects. Functional groups of compost and SOM were investigated using FT-IR spectroscopy and soil organic carbon (SOC). While year …

Search For Host Factors Involved In Attachment Of Agrobacterium Tumefaciens To Plants, Anna Petrovicheva

Dissertations, Theses, and Capstone Projects

Agrobacterium tumefaciens is able to infect a diverse array of plants and causes crown gall disease. Typically these bacteria attach to plant roots and transform the plant cells to induce tumors. The mechanism of this attachment in the infection process is not yet fully understood. Using wild type Arabidopsis thaliana, Columbia-0, and several Arabidopsis mutant lines as a binding target, we screened for A. thaliana mutants with altered adhesion.

The A. thaliana mutant lines were selected in The Arabidopsis Information Resource (TAIR) according to possible location of the resulting protein and similarity to known transformation mutants. Of these mutants …

Systematics And Biogeography Of Orthaea Kloztsch (Ericaceae: Vaccinieae), Nelson Salinas

Dissertations, Theses, and Capstone Projects

In the first chapter a study of the distribution patterns of the neotropical Vaccinieae (Ericaceae) is presented. Five areas of endemism were recovered: Central America, northern Chocó, southern Chocó, eastern Ecuador, and Yungas. Divergence times estimations indicate that the Andean clade of Vaccinieae migrated to South America during the Late Oligocene or Early Miocene (28.9-17.84 MA), and most of the subsequent diversification took place during the Tertiary. The Yungas was the first Andean area to be colonized, and several dispersals towards the north expanded their distribution range. Both areas of endemism and dispersal events were influenced by geological processes, such …

Bacterial Wilt Of Dry-Edible Beans In The Central High Plains Of The U.S.: Past, Present, And Future, Robert M. Harveson, Howard F. Schwartz, Carlos A. Urrea, C. Dean Yonts

Panhandle Research and Extension Center

Bacterial wilt, caused by Curtobacterium flaccumfaciens pv. flaccumfaciens, was first recognized and described as a new dry bean disease near Redfield, South Dakota, after the 1921 growing season on the farm of the Office of Forage Investigations. The grower on this farm informed the federal investigators that he believed the disease to be the same one that killed 90% of his crop in 1920. For the 1921 season, he saved and planted the seed harvested from the previous year, resulting in an estimated 25% loss.

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It is likely that wilt has “reappeared” and become widely established throughout …

Testing Carbon Farming Opportunities For Salinity Management, Peter Ritson, Mike G. Clarke, Adele Killen, Sarah Jeffery

All other publications

An emerging prospect for farm revenue from revegetation of saline and other lands that are marginal or non-productive for agriculture is the sale of carbon credits. Australian Government schemes for carbon credits include the Carbon Farming Initiative (CFI) and the proposed Emissions Reduction Fund (ERF) Therefore, this study aimed to assess the potential for woody vegetation (trees and shrubs) established on and around salt-affected lands in the Northern Agricultural Region (NAR) to remove carbon dioxide from the atmosphere and store (sequester) the carbon in new growth. Revegetation plantings on six farms were selected for the study after the landowners expressed …

Potential Break Crops For Managing Root-Knot Nematode, Carla Wilkinson, Stuart Vincent, Sarah J. Collins Dr

Grain and Other Field Crops Research Articles

Western Australian growers may be unintentionally increasing root-knot nematode, Meloidogyne fallax (False Columbia root-knot nematode) populations by using susceptible break crops between cash crops.

Characterization Of Novel Sorghum Brown Midrib Mutants From An Ems-Mutagenized Population, Scott E. Sattler, Ana Saballos, Zhanguo Xin, Deanna L. Funnell-Harris, Wilfred Vermerris, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for

ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously described sorghum bmr mutants bmr2, bmr6, and bmr12. These tests resulted in the identification of additional alleles of bmr2, bmr6, and bmr12, and, in addition, six bmr …

Assessment Of Rice Self-Sufficiency In 2025 In Eight African Countries, P. A.J. Van Oort, K. Saito, E. Amovin-Assagba, Lenny G.J. Van Bussel, Justin Van Wart, Hugo De Groot, Martin K. Van Ittersum, Kenneth Cassman, M. C.S. Wopereis

Department of Agronomy and Horticulture: Faculty Publications

Most African countries are far from self-sufficient in meeting their rice consumption; in eight countries the production: consumption ratio, ranged from 0.16 to 1.18 in 2012. We show that for the year 2025, with population growth, diet change and yield increase on existing land (intensification), countries cannot become fully self-sufficient in rice. This implies that for the future, a mixture of area expansion and imports will be needed on top of yield gap closure. Further research is needed for identification of most suitable new land for rice area expansion and areas that should be protected.

Patch Burning: Implications On Water Erosion And Soil Properties, Altingul Ozaslan Parlak, Mehmet Parlak, Humberto Blanco-Canqui, Walter H. Schacht, John A. Guretzky, Martha Mamo

Department of Agronomy and Horticulture: Faculty Publications

Patch burning can be a potential management tool to create grassland heterogeneity and enhance forage productivity and plant biodiversity, but its impacts on soil and environment have not been widely documented. In summer 2013, we studied the effect of time after patch burning (4 mo after burning [recently burned patches], 16 mo after burning [older burned patches], and unburned patches [control]) on vegetative cover, water erosion, and soil properties on a patch-burn experiment established in 2011 on a Yutan silty clay loam near Mead, NE. The recently burned patches had 29 ± 8.0% (mean ± SD) more bare ground, 21 …

Productivity And Biological Nitrogen Fixation Of Different Species Of Vetches (Vicia Spp.) Under The Rainfed Conditions Of West Asia, Ali Abd El Moneim, Mohan C. Saxena

IGC Proceedings (1977-2023)

The low rainfall areas of West Asia are characterized by pastoral production system primarily based on small ruminants (sheep and goats). Rangelands serve as the main source of feed. With increasing population, the demand for livestock products has increased. As a consequence, the stocking rates have soared, increasing the pressure on rangelands. Rangeland degradation has therefore been increasing threatening the sustainability of livestock production system and the livelihood of the people dependent on it. Production of additional feed is essential to reduce the pressure on rangelands. Vetches (Vicia spp.) are endemic in the area and can be potential source …

Livestock Production From Grasslands With Improved Management Compared To Traditional Management, Florian Leiber

IGC Proceedings (1977-2023)

The value of traditional versus improved management systems for grassland is discussed. The set target is the persistence of the ecological, economic and social multifunctionality of grasslands and the increase of food output from these areas without increasing parallel requirements for arable crop or energy inputs. Based on the fact that historically traditional systems were stable and sustainable in many cases, while severe damage is faced nowadays, it is argued that lot of improvement should be based on the acknowledgment of successful traditional practises. The challenge might rather be to define improvement as a contemporary development of traditional techniques. The …

Potential Of Forages In Crop Diversification And Crop Rotation, Martin H. Entz, Joanne Thiessen Martens

IGC Proceedings (1977-2023)

Redesign of agricultural systems according to ecological principles has been proposed for the development of sustainable systems. We review a wide variety of ecologically-based crop production practices that focus on forage crops in farming systems and discuss their potential role in enhancing the profitability, environmental sustainability and resilience. Crop-livestock systems that most closely mimic natural systems through appropriate integration of diverse components appear to offer the greatest potential benefits. These systems are more energy efficient and combine high productivity with low ecological footprint. Greater understanding of ecological relationships within crop-livestock systems are required to purposefully and proactively redesign agricultural systems …

Forage Seed Quality: Dormancy, Standards And Quarantine, John G. Hampton

IGC Proceedings (1977-2023)

There are many dimensions to the concept of seed quality. Viable seed which will not germinate when provided with all the requirements for germination is dormant. Forage grasses mostly exhibit non-deep physiological dormancy (PD), while physical dormancy (PY) is common in forage legumes where imbibition is prevented by the seed coat’s impermeability to water (hard seed). Methods for breaking PD and PY to allow germination testing and/or crop establishment are discussed.

In the seed industry seed quality standards are an important feature of quality assurance and may apply for seed production contracts, seed certification, seed sale and seed importing. Standards …

Quality Seed Production And Effective Marketing Systems For Development Of Grasslands, M. Philip Rolston

IGC Proceedings (1977-2023)

Seed quality is defined as (i) maintaining genetic purity using seed certification principles (generation system; isolation; previous cropping history); (ii) achieving high levels of physical purity (especially low weed seed levels) by in field weed control and seed cleaning; (iii) achieving high levels of seed germination at harvest and maintaining germination through the seed supply chain. Seed production systems must not only produce high quality seed but also achieve economic seed yields. Seed crops have to be profitable (by being high yielding) to justify the investment of time and input costs to achieve quality. This in turn requires supporting research …

Scouting Benefits And Developing Innovations In Temperate Grassland To Sustainable Agriculture Production, Walter Ayala, Ethel Barrios, Ignacio Macedo, Jorge Sawchik, José A. Terra

IGC Proceedings (1977-2023)

Agricultural intensification raises concern about land use and future effects to natural resources. The world demand for grain, meat and forest products is increasing constantly. Changes are occurring at large scale, being a compromise for policy makers to contribute to identify opportunities to readdress the productive scenario. There is available technology to reduce impacts, without restricting necessarily productivity. Grasslands provide a large series of economical and ecological benefits to the agricultural systems, being the literature exhaustive in examples. Ley-farming and cover crops technologies are good examples of environmentally sound soil management practices. The society is also worried about an improper …

Evergraze: A Partnership Between Researchers, Farmers And Advisors To Deliver Effective Grassland Management, Warwick B. Badgery, Kate Sargeant, Michael A. Friend, Scott Glyde, Paul Sanford, Ralph Behrendt, Meredith L. Mitchell, Sean Murphy, Angela Avery

IGC Proceedings (1977-2023)

The profitable and sustainable management of livestock production from grassland systems is challenging and it can be difficult to develop a research structure that addresses farmer’s needs and has acceptable rigour and on-ground impact. This paper describes the attributes of research, development and extension (RD&E) programs that are required for a successful partnership between researchers, farmers and advisors. Insights are provided from the EverGraze program that designed, tested and implemented farming systems based on perennial pastures across southern Australia. With this project farmers and advisors were involved in setting research direction, designing experiments, providing strategic guidance over the management of …

Ecologically And Socially Sustainable Livestock Development In Marginal Areas, Ilse Köhler-Rollefson

IGC Proceedings (1977-2023)

“Marginal areas” are perceived as difficult and unproductive landscapes, always under the threat of drought, desertification and poverty. Yet, both dryland and high altitude marginal areas have an extraordinary output of livestock products; in the efficiency of producing human-edible protein they far surpass more fertile areas. This productivity under adverse climatic conditions rests on sophisticated strategies and social institutions developed by pastoral communities to deal with variability in the availability of resources. It depends on the use of animal genetic resources that are adapted to make best use of local vegetation and can cope with seasonal variations in availability. Livestock …

Valuing Variability--New Perspectives On Climate Resilient Dryland Development, Saverio Kratli

IGC Proceedings (1977-2023)

Valuing Variability is a challenge to the view of the drylands as naturally vulnerable to food insecurity and poverty. It argues that improving agricultural productivity in dryland environments is possible by working with climatic uncertainty rather than seeking to control it – a view that runs contrary to decades of development practice in arid and semi-arid lands.

Participatory And Holistic Approaches With Grassland Farmers And Development Of Policies, Alain Peeters

IGC Proceedings (1977-2023)

The world is changing rapidly. Grassland farmers and ruminant livestock breeders will have to adapt to these changing environmental, social and economic conditions. Research can help them at the condition that linear ‘top-down’ technology transfer methods are abandoned for the benefit of participatory and holistic approaches. These approaches classified in the generic term of ‘Farming System Research’ consider farmers as real research partners, and they merge farmer’s and scientist’s ideas with those of other stakeholder types. They combine scientist’s and farmer’s knowledge for creating fast innovations, easily adopted by farmers since farmers themselves contribute to their design and their development. …