Agronomy and Crop Sciences Commons^™

Development Of Environmental And Agricultural Professionalism, Robert F. Barnes, Thomas J. Hall

IGC Proceedings (1977-2023)

The American Society of Agronomy {ASA) is' co-ordinating the development of a \ioluritary certification programme for the men and women who··make nutrient management strategies for farmers .• This paper examines the need, "history and obstacles in developing a crop advisor certification programme. Past arid proposed state and national legislative initiatives have indicated to some industry leaders that certification programmes' will be needed ·to operate in the coming regulat6ry environment. Other members· of industry· feel chat voluntary certification will bring on mandated programmes, The' differences in outlook, the diversity of the audience and the academic orientation of ASA ·have all created …

Grazier's Pattern Of Understanding Vegetation In The Semi-Arid Rangelands Of New South Wales, S.M M. Kersten, R L. Ison

IGC Proceedings (1977-2023)

A matrix ranking (MR) technique was used by graziers in western New South Wales to rank rangeland plants according to preference. Graziers preferred a variety of plant species in their paddocks: "bushes" and "50f1 feed", perennials and annuals, winter-and summer­growing plants, on both stock-based and non-stock-based criteria, The criteria for evaluation were rarely independent of each other nor of different soil types on the grai:ier's property. Drought resistance was perceived as one of the more important criteria, followed by stock-based criteria such as "nutritious", "palatable" or "quick fattening" stock feed. The utility of MR for allowing graziers' knowledge to be …

Composition Of The Fractions Of Dry, Mature Subterranean Clover Digested In Vivo And In Vitro, L Klein, S K. Baker

IGC Proceedings (1977-2023)

A modified pepsin-cellulase procedure was used to improve the prediction of in vivo digestibility of dry, mature subterranean clovers (Trifolium subterraneum). Feed, faeces, and the residues from this /11 vitro procedure and the i11 vitro procedure of Tilley & Terry were analysed for protein, ash and fibre fractions lo determine the composition of the cell-wall functions that were digested. The extent of digestion of the cell-wall fractions differed between the two in vitro procedures, but the cell-wall fraction that was digested contained similar proportions of cellulose, hemicellulose, protein and lignin. The cellulose and protein contents of the cell-wall digested …

Effect Of Plant Leaf Age On The Production Of Tannins, Phenols, Proanthocyanidins And Flavanols In Eulalia Villosa, M M. Wolfson, E W. Du Toit, P Chesselet

IGC Proceedings (1977-2023)

Histochemical and biochemical analyses have confirmed the presence of condensed tannins in a number of southern African tropical grasses. The ability to precipitate proteins, total phenols, condensed tannin and proanthocyanidin levels were significantly higher in mature leaves of Eulalia villosa than in young leaves. The ratio of condensed tannin to Jlavan 3,4-diols indicated that the young leaf material contained more monomeric unpolymerised flavan 3,4-diol units than mature leaves. The trend is repeated in the ratio 'of proanthocyanidin to flavan-4-ols, These low molecular weight proanthocyanidin precursors probably do not have the ability to precipitate proteins, The histochemical tests can be used …

Effect Of Inoculants And Absorbents Incorporated In Grass Silage On Silage Quality, Effluent Production And Animal Performance, Raymond Jones

IGC Proceedings (1977-2023)

Unwilled ryegrass crops (151 kg DM) were enslled in 70-t bunker silos. Crop analysis (g/kg/DM) was water-soluble carbohydrates 153, nitrogen 24.1 and predicted digestibility (DOMD) 0.67. Molassed sugar beet feed pellets were incorporated at a rate of 25 kg/t in the harvested crop with or without inoculant treatment ("Live Systems", MMB, UK), and compared with a control silage with no additive. Absorbent addition with or without inoculant significantly reduced silage pH and ammonia-N compared with the control. Inoculant treatment further increased lactic acid content. Silage effluent production was reduced by up to 33% by absorbent inclusion with effluent DM losses …

Near-Infrared Spectroscopy Analysis Of The Nutrient Content Of Dairy Pastures, R C. Kellaway, C Stimson, R J. Tassell

IGC Proceedings (1977-2023)

Pasture samples from temperate and tropical species were collected before and after grazing, at regular intervals, on 3 dairy farms in New South Wales over a period of 3 years. All samples (n=693) were analysed on a near-infrared (NIR) spectrophotometer with a scanning monochromator. Subsets of samples selected for calibration and validation, were analysed by wet chemistry methods for estimated metabolisable energy (MID), crude protein (CP), organic matter (OM), acid-detergent fibre (ADF), Ca, P, Mg, K, Na, S, Cu, Mn and Zn. These data were used lo develop NIR equations using partial least squares analyses. Standard errors of laboratory analysis …

Influence Of Oxygen Leakage Through Stretch Film On Quality Of Round Bale Silage, P Lingvall, C M. Pettersson, P Wilhelmsson

IGC Proceedings (1977-2023)

The ensiling-process is based on anaerobic conditions. Therefore, it is important to get "air tight" parcels covering big-bale silage. Wrapping round bales wilh stretch film has improved silage quality, and reduced diy matter (OM) and energy losses. In this experiment we studied the influence of stretch film quality, film thickness, .storage temperature and storage place on fermentation, microbial growth/ and DM losses. Additionally, oxygen permeability of stretch film wrapped in 4 or 6 layers around artificial bales (metal) and DM losses was tested In a model. High storage temperature, low total film thickness and high film permeability to oxygen increased …

Rotary Spading To Ameliorate Soil Water Repellence, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

One-off deep cultivation can reduce the severity of soil water repellence by mixing some of the repellent topsoil into the wettable subsoil and bringing wettable subsoil to the surface.

Rotary spading or deep cultivation increases water infiltration by providing pathways for water entry; diluting the water repellent soil with non-repellent soil; increasing the breakdown of soil organic matter causing water repellence; in some soil types, spading and other deep cultivation can lift subsoil with higher clay content to the surface.

Deep cultivation increases the risk of wind and water erosion. To minimise the risk of erosion, follow the guidelines on …

Detection Of Fungicide Resistance In Population Of Corynespora Cassiicola From Arkansas Soybean And Cotton Fields, Rafael Zaia

Graduate Theses and Dissertations

Target spot, caused by the fungus Corynespora cassiicola, has reemerged since 2016 as an economically important disease on soybean and cotton across the Southern U.S. The quinone outside inhibitors (QoI) and succinate dehydrogenase inhibitors (SDHI) are important fungicide classes used to control foliar diseases in soybean and cotton. The efficacy of these products is rapidly decreasing, impacting control, and causing significant yield losses. The overall objective of this study was to determine the risks associated with chemical control by screening fungicide sensitivity, evaluating target site alterations, and analysis of disease control efficacy and yield response of fungicides for soybean in …

Oats – Essentials For Growing A Successful Crop, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Oats in Western Australia are grown for grain, hay, grazing, or silage. Each year, between 250,000 and 350,000 hectares are sown for grain production. This page provides essential management practices for growing a successful oat crop.

Hay – Essentials For Growing A Successful Crop, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Export hay fits into most of the accepted cropping rotations and helps reduce weed seed banks, overcome herbicide resistance, provides a break from traditional chemical regimes and good paddock preparation for the subsequent crop, and is an alternative profitable crop.

Talk to your local hay exporter about their requirements for hay produced for export before sowing oats for export hay. Hay exporters have different requirements, which will affect how you manage your crop.

Developing A Controlled Traffic (Tramline) Farming System, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Controlled traffic farming (CTF) is a farming system built on permanent wheel tracks where the crop zone and traffic lanes are permanently separated. It can improve profitability and sustainability.

Implements for seeding, spraying, spreading and harvesting have a particular span, or multiple of it, and all wheel tracks are confined to specific traffic lanes.

CTF increases profit by more yield, better grain quality, improved operation timeliness, and reduced costs. The environment can improve, with less nutrient leaching, less water erosion, better water infiltration, and less greenhouse gas emission. Implementation needs a clear, long-term plan, and prioritisation of soil health.

Another …

Assessing Soil Properties & Suitability For Optimized Irrigation Development In Sudan, Northern Africa, Suhib O. Hamid

Department of Agricultural and Biological Systems Engineering: Masters Project Reports

In Chapter 1, soil properties essential for efficient irrigation are thoroughly assessed. Factors such as soil texture, infiltration rates, and nutrient content are analyzed to provide insights into the selection of modern irrigation systems. Utilizing data collected from 3,192 locations through GPS and laboratory analyses, alongside sophisticated ranking systems, the research determines the most suitable irrigation methods for specific soil series. Findings highlight the remarkable efficiency of drip irrigation across various soil types, contrasting with the consistently lower performance of surface irrigation. The chapter emphasizes the significance of considering soil variability, evapotranspiration, and investment factors in selecting irrigation methods for …

Key Stages In The Growth And Maturity Of Field Pea, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Many farm operations rely on a clear understanding of the stage of crop development. This factsheet describes key growth stages of field pea, which will aid growers and their advisers in determining the appropriate timing for the application of herbicides, crop-topping, swathing, and harvest.

There is likely to be considerable variability in a crop, particularly at maturity and harvest. Therefore, it is often necessary to estimate the average or majority development stage of a crop. At first, this is best done numerically, but with experience it can be done by eye.

Button Grass And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Button grass (Dactyloctenium radulans) is a native species found throughout Australia. It is a common summer weed species that depletes soil moisture and nutrients, reducing the yield potential of the subsequent crop. It also acts as a green bridge for crop pests and disease.

The rapid emergence and growth of button grass after rainfall makes it important for the Australian plague locust.

It can be a valuable pasture species in arid areas, although overgrazing of button grass can result in toxicity for sheep and cattle.

Assessing Even Flat-Fan Nozzles For Spot Spray Herbicide Applications, Thiago H. Vitti

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Herbicide efficiency in row-crop agriculture can be improved using precision technologies for controlling weeds and minimize agronomic, economic, and environmental impacts. Site-specific weed management technologies, such as spot-sprayers, allow herbicides to be sprayed only where weeds are present in the field. Understanding application parameters and their influence on weed control for site-specific spot-spray applications is essential. This research involved laboratory and greenhouse studies to investigate the coverage and coefficient of variation (CV) of even flat-fan spray nozzles under different spot-spray application scenarios, as well as the effect of weed size and application method on the control of various weed species …

Identifying Genes Linked To Variation In Metabolic And Whole Plant Phenotypes Using Data From Genome Resequencing, Transcriptomics, And Metabolic Profiling Of A Field-Grown Maize Diversity Panel, Ramesh Kanna Mathivanan

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Maize metabolism is highly complex and influenced by genetic variation, yet the specific genes contributing to this variation and their links to non-metabolic traits remain less understood. To address this knowledge gap, we identified genes involved in maize metabolic variation and linked them to non-metabolic traits. We utilized a quadruplicate dataset of whole genome resequencing, transcriptomic, metabolic, and whole plant phenotype data from a single common field experiment of 660 diverse maize inbred lines. Leaf samples were collected shortly before flowering and analyzed using GC-MS for 26 metabolites. A Resampling Model Inclusion Probability Genome-Wide Association Study (RMIPGWAS) of approximately 2.6 …

Assessment Of The Drivers Of Adoption Of Climate Smart Agriculture Practices Among Field Crop Farmers In Zambia, Faindani Nyirenda

Graduate Theses and Dissertations

Climate smart agriculture (CSA) practiced has been promoted in Zambia since the 1980s to address the declining crop productivity due to increased occurrence of drought or dry spells caused by climate change. Despite considerable research indicating that CSA practices have many potential benefits such as increased yield and income, the adoption rate in southern Africa is still low especially where farmers have stable off farm income. This might be because most of the research and promotion has been directed to the main staple crop maize and other context specific impacts related to agroecological and socioeconomic heterogeneity. In this study we …

Integrating Water And Nitrogen Management For Sustainable Agriculture: Optimizing Resource Use Efficiency And Maximizing Crop Productivity, Jiaming Duan

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Advisors: Derek Heeren and Daran Rudnick Maize, accounting for over 95% of national grain production in the United States, is highly sensitive to water and nitrogen (N) inputs. Conventional agricultural practices often lead to excessive application, causing groundwater contamination through nitrate leaching. Therefore, there is a demand for integrating water and nitrogen management with innovative scheduling methods for sustainable agricultural development.

This dissertation first reviewed two decades of U.S.-based research, highlighting the optimal management of water and N to enhance yield, water use efficiency (WUE), and nitrogen use efficiency (NUE). Findings indicate that maintaining optimal levels of N and water …

Dynamics Of Soybean Seed Protein And Oil Content With Depth In The Canopy, Hafith Furqoni

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Understanding the physiological basis of variation in seed composition is critical for optimizing soybean seed composition. Also, studying dry matter accumulation and nitrogen uptake, partitioning, and redistribution in soybeans is crucial due to its direct impact on seed yield levels and overall plant productivity. This study aimed to test the primary proxy influencing seed protein and oil content, which is their accumulation rate determined by the assimilate supply per seed. The second objective was to comprehensively understand soybean dry matter (DM) accumulation and nitrogen (N) uptake, partitioning, and removal patterns within the canopy. Field experiments were conducted using two soybean …

Integration Of Matlab And Machine Learning To Accelerate Evaluation Of Biological Activity In Agricultural Soils And Promote Soil Health Improvement Goals, Andrew Stiven Ortiz Balsero

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Traditionally, assessments of soil biological activity have been confined to laboratory settings, creating a disconnect with practical in-field methods. To bridge this gap, cotton fabric degradation has been used to illustrate soil microbial activity under different management practices. While effective, these demonstrations are subjective and labor-intensive.

Researchers have explored using image processing software like ImageJ and Adobe Photoshop to streamline this process. Although these tools accurately quantified fabric degradation under varying soil conditions, the methods remained labor-intensive and complex. Consequently, these methods were still not ideal for on-farm use by agricultural practitioners.

To further address labor and complexity limitations, the …

The Effects Of Cover Crop Adoption On Yield Distributions Under Extreme Drought, Emory Johnson

Graduate Theses and Dissertations

Increased frequency and severity of extreme weather events due to climate change negatively impact agriculture output. Of particular concern is the adverse impact of droughts on corn and soybean yields, as these crops represent a significant portion of cash crop receipts in the United States. Cover crops are one practice that has gained attention due to their agronomic benefits and their potential to reduce downside production risk for producers. This study focuses on the impact of cover crop adoption on corn and soybean yields during drought conditions. We use cover crop adoption data from the Operational Tillage Information System, RMA …

Agronomic Practices To Enhance Weed Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Some agronomic practices, such as crop choice and sequence and improving crop competition and pasture competition, can improve crop environment and growth, and the crop's ability to compete with weeds.

B.R. Wells Arkansas Rice Research Studies 2023, J. Hardke, X. Sha, N. Bateman

Arkansas Agricultural Experiment Station Research Series

Arkansas is the leading rice producer in the United States. The state represents 49.0% of total U.S. rice production and 49.6% of the total acres planted to rice in 2023. Rice cultural practices vary across the state and across the U.S. However, these practices are also dynamic and continue to evolve in response to changing political, environmental, and economic times. This survey was initiated in 2002 to monitor and record changes in the way Arkansas rice producers approach their livelihood. The survey was conducted by polling county extension agents in each of the counties in Arkansas that produce rice. Questions …

Enhancing Crop Resilience: Physiological And Omics Approaches For Drought And Heat Stress Tolerance In Soybean And Peanut, Jyoti Prasad Kakati

All Dissertations

Soybean and peanut are two major crops globally grown for oil and protein. Climate change-associated factors like drought and increased temperature (heat stress) challenge the global production of soybeans and peanuts. Though the United States is the second-largest producer of soybean and the fourth-largest producer of peanuts, it still faces production constraints associated with drought and heat stresses. In the present study, we have examined the responses of soybean and peanut plants to drought and heat stresses during germination and reproductive phases. We conducted field and controlled environmental studies to elucidate the impact of drought stress on germination and seedling …

Use Of Herbicides Coated Onto Fertilizer And Applied Over-The-Top Of Cotton, Summer Linn

Graduate Theses and Dissertations

Cotton (Gossypium hirsutum L.) production faces numerous challenges, many related to weed management. A herbicide application method that focuses on combing resources that producers already have access to, such as herbicide-coated fertilizers, could be a practical approach for addressing late-season control of Palmer amaranth (Amaranthus palmeri S. Wats) and other problematic weed species. Two main factors would potentially impact the efficiency of utilizing this method: cotton tolerance to the application and weed control provided by the herbicide-coated fertilizers. Some considerations could affect the efficacy of these applications, such as when the treatments are applied and when they are activated by …

Evaluation Of A Diflufenican:Metribuzin:Flufenacet Premixture For Soybean Tolerance And Weed Control, Matthew Coleman Woolard

Graduate Theses and Dissertations

Palmer amaranth [Amaranthus palmeri (S.) Wats.] and waterhemp [Amaranthus tuberculatus (Moq.) Sauer] ranks among the most troublesome weeds of soybean [Glycine max (L.) Merr.], having evolved resistance to multiple herbicide sites of action. Bayer CropScience has announced its intentions to launch Convintro™ brand herbicides, one being a three-way premixture for use preplant until 3 d after planting in soybean. The premixture will include diflufenican (WSSA Group 12), metribuzin (WSSA Group 5), and flufenacet (WSSA Group 15) (DFF-containing premixture), adding a new site of action for use in soybean throughout the United States. In 2022 and 2023, field trials were conducted …

Approaches To Controlling Palmer Amaranth And Its Interference In Furrow-Irrigated Rice, Tanner Austin King

Graduate Theses and Dissertations

Palmer amaranth (Amaranthus palmeri S. Wats) is the most troublesome and problematic weed in most mid-southern U.S. row crop production systems. With the increased adoption of furrow-irrigated rice (Oryza sativa L.), there is a greater occurrence of Palmer amaranth due to sustained moist conditions allowing continual emergence of the weed throughout the growing season. Palmer amaranth has previously been shown to negatively affect crop yields when left unmanaged. Therefore, there is a high potential for rice yield loss due to the weed’s ability to emerge over an extended period and interfere with crop development. However, there is a lack of …

Evaluation Of A Capsule Suspension Formulation Of S-Metolachlor For Use In Fenclorim-Treated Rice And Wheat, Samuel Charles Noe

Graduate Theses and Dissertations

The continued evolution of herbicide resistance is one of the primary concerns facing Arkansas growers today. Problematic weeds such as barnyardgrass [Echinochloa crus-galli (L.) Beauv.] and Italian ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] have evolved resistance to some of the most used herbicides in rice (Oryza sativa L.) and wheat (Triticum aestivum L.). To counteract this resistance, alternative herbicide sites of action should be explored. S-metolachlor is a very-long-chain fatty acid (VLCFA)-inhibiting herbicide [Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Group 15] commonly used in U.S. row crops to control grasses and small-seeded broadleaf weeds. …

Assessment Of American Tannin-Free Grain Sorghum As Feedstuff For Poultry: Nutrient Composition, Amino Acid Digestibility And Bird Performance, Santiago Sasia

All Dissertations

Given the rising cost of poultry diets, alternative ingredients like sorghum are crucial for maximizing returns without compromising product quality. Sorghum's drought tolerance and adaptability, along with its nutritional profile, make it a viable corn substitute. This dissertation examines the nutrient composition, amino acid digestibility, and performance of poultry fed with American tannin-free grain sorghum. Chapter II evaluates the impact of sorghum-based diets, with or without phytase superdosing, on broiler performance, including body weight, weight gain, feed intake, and feed conversion ratio. Results indicate that sorghum can replace corn without adverse effects on broiler performance. Chapter III explores the partial …