Agronomy and Crop Sciences Commons^™

Wild Oat And Its Management In Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Wild oats (Avena fatua and A. ludoviciana) represent a large cost to cropping; they are highly competitive and when left uncontrolled, can reduce wheat yields by up to 80%.

The greatest yield loss occurs when wild oat plants emerge at the same time as the crop.

Evaluating A Precision Sprayer For Detecting Weeds And Spraying Herbicides In Real Time (Spot Spray) For Weed Management In Corn And Soybean, Adam Eric Leise

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

Herbicide sprayers are becoming larger and more efficient in applications in crop fields. A precise and efficient herbicide application is advantageous in effective weed control. New precision sprayers were introduced in hopes of reducing the amount of herbicide applied. Greeneye Technology and John Deere have developed precision sprayers for the detection of weeds in crop fields, which come equipped with a dual tank system that allows for two different herbicides to be separated from tank to tip. The objectives of this study were to evaluate the broadleaf and grass weed control efficacy of spot spray (SS) technology when applied in …

Triticale As A Source Of Resistance To Wheat Streak Mosaic Virus And Triticum Mosaic Virus, Marcos Winicius Goncalves De Souza

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

Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) present a great threat to wheat production in the Great Plains area of the United States due to the loss of photosynthetic area causing reductions in crop yields. Effective control of these viruses is limited to a few available strategies including controlling volunteer wheat and using currently identified resistant genes to both the vector and viruses. While effective, these genes show temperature sensitivity and yield drag, and evidence that the vectors and viruses can overcome them has been found. Thus, new methods of genetic resistance are urgently needed. Field observations …

Integrating Remote Sensing And Machine Learning To Determine Past, Current And Future Crop Water Use From The Nubian Sandstone Aquifer System, Moaz Ishag

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

The agriculture sector is a significant consumer of water, and sustainable water use begins with monitoring irrigated land. Delineating irrigated land supports decision-makers and promotes the sustainable use of this crucial resource. This study focuses on the Nubian Sandstone Aquifer System (NSAS), the largest aquifers in the world, which spans Egypt, Sudan, Libya, and Chad. The study aims to: 1) quantify the increase in irrigated hectares (both pivot and non-pivot) from 2000-2001 to 2023-2024; 2) identify major irrigated crop types and their water requirements; and 3) quantify groundwater crop water use from the NSAS using remote sensing via the Google …

Unmanned Aerial Vehicle (Uav)-Based High-Throughput Phenotyping For Maize Improvement, Eric T. Rodene

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

Modern breeding programs rely heavily on efficiently screening large numbers of genotypes for agronomic traits, such as disease resistance, drought tolerance, and yield. Identifying the genetic loci or genes associated with these traits using GWAS or functional analyses will benefit future plant breeding efforts seeking to incorporate these traits into new crop varieties, whether through conventional breeding or gene editing techniques. Unmanned aerial vehicle (UAV)-based image data has been increasingly used for this task, as it allows entire test plots to be quickly and cost-effectively phenotyped. In my research, I have developed methods to improve the accuracy of machine learning …

Exploring Producers' Willingness To Pay For Ecosystem Services: Three Essays On Soil Health, Location Preferences, And Cover Crop Adoption, Kaouter Essakkat

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

This dissertation comprises three essays: one assessing Midwest producers' willingness-to-pay (WTP) for soil health-enhancing ecosystem services (ES), another examining the impact of policy implementation locations on WTP, and a third identifying factors influencing producers' adoption of cover crops (CC).

The first essay pioneers the understanding of agricultural producers’ valuation of soil health-associated ES amid growing concerns of soil degradation due to agricultural intensification. Using a discrete choice experiment, this study assesses producers’ WTP for a policy that incentivizes ES provision, specifically improved water quality, carbon sequestration, and enhanced crop yield. Surveying producers across Iowa, Kansas, and Nebraska, our results show …

Assessment Of Foam Decontamination In Tomato Washing Process, Basim M. Alohali

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

The work of the dissertation investigated the efficacy of foam-based decontamination treatments to enhance microbial safety in Roma tomatoes, specifically targeting natural microflora and Salmonella contamination. Growing concerns over foodborne illnesses linked to fresh tomatoes and the limitations of conventional decontamination techniques, such as organic matter built-up and limited microbial reduction, are addressed. The primary objectives were to characterize the physiochemical properties of foams formed using various concentrations of Tween 20 (T20) and sodium dodecyl sulfate (SDS) with and without the addition of sodium hypochlorite (NaOCl) and peracetic acid (PAA), compare the efficacy of foam and traditional dump tank (DT) …

Brome Grass And Its Management In Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Brome grass (Bromus spp.) is one of the most competitive grass weeds in wheat. Over the last 10 years, brome grass has increased in importance to a greater extent than any other weed species in Australia.

Recent changes in crop production systems, increased conservation tillage, a lack of available selective herbicides, and a decline in system diversity have seen an increase in the importance of this weed in Western Australia (WA).

Seed is the main source of brome grass infestation and, as few seeds remain dormant, the most important aspect of management is to reduce its seed bank.

Annual Ryegrass And Its Management In Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Annual ryegrass (Lolium rigidum) is one of the most serious and costly weeds of annual winter cropping systems in southern Australia. It is highly competitive and can compete with a crop as early as the 2-leaf stage.

Annual ryegrass is a winter to spring growing weed that can emerge from late autumn to early spring. The number of emergence flushes and the density of plants that emerge are related to initial seedbank levels and the frequency and amount of rainfall.

Assessing Soil Properties For Optimized Irrigation Development In Sudan, Northern Africa, Suhib Hamid, Derek M. Heeren, Aaron R. Mittelstet, Saleh Taghvaeian, Randall S. Ritzema

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Sustainable irrigation methods maximize agricultural productivity in Northern African countries like Sudan. This project evaluates soil properties to develop optimized irrigation strategies for Sudan's arid and semi-arid climate. Assessing soil characteristics such as texture, infiltration rates, and nutrient content informs the selection of modern irrigation systems. Data from 3,192 locations, collected using GPS and ring infiltrometers for infiltration rates, alongside laboratory analyses for soil properties, were employed. A ranking system determined suitable irrigation systems for specific soil classes, considering factors like slope, wind, crop tolerance, available water capacity (AWC), drainage, germination, capital cost, labor cost, maintenance, and evapotranspiration (ET). The …

Investigating The Abilities Of Potentially Beneficial Bacteria For Increasing Nitrogen-Use Efficiency In Maize, Lexie R. Foster

School of Biological Sciences: Dissertations, Theses, and Student Research

Global agriculture relies heavily on the use of synthetic nitrogen fertilizer to meet the current global food demand. Unfortunately, the average nitrogen-use efficiency (NUE) of maize (Zea mays) is approximately 50 percent. Improving the NUE of maize is essential for meeting the growing global food demand while also decreasing the negative environmental impacts caused by losses of nitrogen fertilizer due to runoff and volatilization. Harnessing the symbiotic relationship between plants and the soil microbiome may be one method for increasing the NUE in crops such as maize. In the present study, a set of potentially beneficial bacterial species …

Arkansas Corn And Grain Sorghum Research Studies 2023, Jason Kelley, Travis Faske

Arkansas Agricultural Experiment Station Research Series

The 2023 edition of the Arkansas Corn and Grain Sorghum Research Studies Series includes research results on topics pertaining to corn and grain sorghum production, including weed, disease, and insect management; economics; irrigation; agronomics; soil fertility; mycotoxins; cover crop management; and research verification program results. Our objective is to capture and broadly distribute the results of research projects funded by the Arkansas Corn and Grain Sorghum Board. The intended audience includes producers and their advisors, current investigators, and future researchers. The Series serves as a citable archive of research results.

Evaluating Injury Risk Caused By Potential Drift Of Florpyrauxifen-Benzyl Or Quinclorac In Corn, Amar Godar, Jason K. Norsworthy, L. Barber

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Of relevance to the off-target movement of herbicides in Arkansas is the drift of rice herbicides in the state’s agricultural landscape, where aerial application of herbicides is common, raising the prima facie question of the risk of damage to other sensitive crops. The aim of this study was to evaluate the response of corn to postemergence applications of florpyrauxifen-benzyl or quinclorac, which were applied directly to the crop at low rates (0.78 or 1.56 to 12.5% of the normal use rate for labeled crops). This was investigated through three site-year field experiments conducted in Fayetteville (2020 and 2021) and Tillar …

Pixel-Based Spatiotemporal Statistics From Remotely Sensed Imagery Improves Spatial Predictions And Sampling Strategies Of Alluvial Soils, Marcelo Mancini, Hans Edwin Winzeler, Joshua Michael Blackstock, Phillip R. Owens, David D. Miller, Sergio H.G. Silva, Amanda Ashworth

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Alluvial plains are vexing landscapes for soil mapping and spatial soil property predictions. Alluvial sediments often exhibit unpredictable spatial variability from both fluvial and anthropogenic disturbance. The determination of optimal number of soil sampling points for capturing soil variability remains a persistent issue for mapping and monitoring soil conditions. Here, soil organic matter (SOM) and cation exchange capacity (CEC) were estimated in an alluvial plain from a dense array of 2145 soil samples over 250 ha. The primary goals were to i) use pixel-based statistics from time-series Sentinel-2 satellite reflectance data to estimate SOM and CEC; ii) evaluate the use …

A Comparative Review Of Soil Carbon Sequestration Methods In Brazil’S Agriculture, Skylar Cheng

Discussions

Brazil is under unique pressure to adopt sustainable agricultural practices due to its intricate biodiversity and globally dominant agricultural sector. Increasing soil degradation, agricultural land expansion, and rising levels of atmospheric carbon are nationwide concerns that require multifaceted solutions. Integrated agricultural systems, which rehabilitate soils through crop, forage, and livestock rotation as well as biochar—a carbon-rich soil amendment—can address such concerns. These sustainable farming practices improve carbon sequestration and soil fertility; however, uptake remains minimal due to environmental, economic, and policy barriers. Accordingly, this paper proposes a comprehensive model of integrated systems and biochar, in which the benefits of one …

Evaluating Past Progress And Assessing Prediction Breeding Strategies For Sustained Genetic Gains In The Louisiana Sugarcane Variety Development Program, Brayden A. Blanchard

LSU Doctoral Dissertations

The aim of this dissertation is to outline important considerations for the Louisiana Sugarcane Variety Development Program (LSVDP) as it pertains to historical progress, impact, goal setting, and new strategies for continued genetic gains. Industry progress was evaluated with robust regression models to quantify rates of productivity gains. Over the last 50 years, statistically significant productivity gains were identified in sucrose content (45%), cane yield (32.2%), and sugar yield (93%) while pairwise comparisons of decades showed that progress was incremental rather than rapid and sustained once achieved. The decade from 1990-1999 was identified as the only decade with a significant …

The Potential Impact Of Endangered Species Legislation On Federal Grazing Lands And The Livestock Industry, G M. Luciuk, B Bristol, T W. Weins, D M. Boyle

IGC Proceedings (1977-2023)

Crown based grazing is an integral part of the management structure of cattle operations, and is very important to the economic fabric of rural communities. Federal crown lands, such as the PFRA operated community pastures are an integral part of the resource conservation efforts in western Canada. These lands represent a significant reservoir of the remaining natural lands which are important for wildlife habitat. Sustainable management of such contiguous blocks of land is essential for the maintenance of biodiversity. Proposed endangered species legislation would require the development of recovery plans on federal lands for endangered, threatened and extirpated species. Rural …

Concepts For Mining Landscape Development In Eastern Germany With Grazing Animals And Agroforestry, S Eichler, F Herzog

IGC Proceedings (1977-2023)

Leipzig South (Saxony) has been heavily transformed by open cast lignite mining. Alternative forms of land use are sought which contribute to an increase of biodiversity and an improvement of soil quality. This could be achieved by the selective introduction of grazing animals and perennials. Specific scenarios for open pits, dumping areas, open pits’ slopes and land reclaimed for agriculture are proposed. Socio-economic drawbacks are outlined.

The Use Of Grasslands To Improve Water Quality In The New York City Watershed, D J. Flaherty, J Drelich Jr

IGC Proceedings (1977-2023)

The purpose of this paper is to demonstrate how grasslands are used in the New York City (NYC) Watershed to improve water quality. A Watershed Agricultural Program was established to voluntarily implement Pollution Prevention Best Management Practices on watershed farms. Grasslands have been used in Whole Farm Plans to reduce nutrients, sediments and other toxic materials reaching New York City’s water supply. Rotational grazing has been used to limit access to streams and stream banks and improve nutrient distribution on pastures. Improved grassland management also helps correct the nutrient balance on the farm and facilitates better nutrient management. Brush removal …

Objective Indicators For Monitoring Drought In Grasslands, D H. White, S M. Howden

IGC Proceedings (1977-2023)

Australia’s National Drought Policy was ratified by the Commonwealth (Federal), State and Territory governments in 1992. However, a sequence of El Niño-based events that started in Queensland in 1991 culminated in much of Australia experiencing abnormally low rainfall throughout 1994 and into 1995. Many farmers experienced substantial loss of income. The Commonwealth government therefore devised measures to determine which areas had been exposed to exceptional drought so that financial assistance could be directed as effectively as possible. In this paper we discuss progress in developing regionally-sensitive indicators and methodologies to aid in future assessments of drought exceptional circumstances.

Are We Ignoring Science In Our Quest For Simplicity In Range Management?, W A. Laycock

IGC Proceedings (1977-2023)

Accurate determination of range condition and trend is essential for proper range management. In the United States, the range condition model currently used is not based on up-to-date ecological knowledge. It assumes a single stable state (climax) and linear pathways. Multiple stable state models more accurately depict community dynamics but have not been widely accepted. U.S. Federal land management agencies are using surrogates, such as qualitative “instant trend” measures and substitution of utilization for measured condition and trend to guide management. Most of these short cuts are not based on science. Attacks on livestock grazing by environmentalists are based on …

Socio-Economic And Climate Change In Mongolia - Effects On Grassland Ecosystems, C Opp

IGC Proceedings (1977-2023)

In Mongolia, in combination with strong changes of the whole society during the past 76 years, from the feudal system to socialism and from the socialist system of planned development to the market economy, there are a lot of changes in the use of natural resources all over the country. In consequence of this a lot of effects on grassland ecosystems, caused by socio-economic and climate driving factors, were observed and studied in different scales: zonal, regional, local.

Integrating Biophysical And Economic Models For Assessing Impacts Of Change On Grazingland Ecosystems, J De Souza Neto, J R. Conner, J W. Stuth, W T. Hamilton, J W. Richardson

IGC Proceedings (1977-2023)

PHYGROW, a hydrologic-based forage simulation model, was parameterized to represent a typical South Texas ranch engaged in the production of cattle and meat goats with an indigenous population of white-tailed deer. Forage production and associated stocking rates for two cattle: goat ratios were simulated for 20 years. Two, ten-year weather scenarios, one representing normal conditions (30% drought years) and one representing dryer weather conditions (50% drought years) were analyzed. Management decision rules were developed for the region to produce estimates of annual animal production and operating cost for the enterprises in each of the four scenarios. These performance and cost …

Linear And Community-Based Processes Of Ethical Decision Making For Grassland Workers, Gary W. Fick

IGC Proceedings (1977-2023)

Grasslands are basic elements in sustainable development, but few grassland workers are familiar with concepts of ethical decision making useful in integrating ecological, economic, and sociological components of sustainability. Most published procedures for ethical decision making are based on linear models for individualized social systems with modern technologies. In the context of sustainable agriculture, nonlinear community-based procedures may be more appropriate. In this paper, a nonlinear model from the Haudenosaunee (Iroquois) Indians is compared to more conventional linear procedures. After identification of a problem, linear models often leave the solution of the ethical dilemma (ranking ethical goals when they conflict) …

Policy Options For Decreasing N And P2o5 Losses From Grassland Based Dairy Farms, P.B M. Berentsen, G.W J. Giesen

IGC Proceedings (1977-2023)

Policy instruments for reducing nutrient losses include extension and education, research, financial incentives such as subsidies and levies, and regulations. The potential of these instruments for reducing nitrogen (N), phosphate (P2O5), and ammonia (NH3) losses is examined for Dutch specialized dairy farms on sandy soils. A linear programming model is used to estimate policy impacts. Results indicate that efficiency improvements through extension, education, and research alone have the potential to decrease total N losses to government target levels in 2005 and to erase 92% of the gap between base and target P2O5 losses, but only 24% of the corresponding NH3 …

Production V Conservation: A Policy Dilemma In The Tree Clearing Debate In Queensland, Australia, J C. Scanlan, E J. Turner

IGC Proceedings (1977-2023)

A process for developing policy for tree clearing that meets the competing goals of conservation and production has been followed. There were two levels at which policy was developed. An overall Statewide policy outlined general targets to meet commitments of the Queensland Government. Local guidelines were developed by a large number of groups containing representatives of government and interested conservation movement and industry representatives. The policy and the local guidelines are an important part of the process used to assess applications for permits to clear woody vegetation.

Forage Production And Performance Of Beef Yearlings Grazing Diploid And Tetraploid Crested Wheatgrass, J D. Bruynooghe, R.D H. Cohen, N W. Holt, P G. Jefferson

IGC Proceedings (1977-2023)

A series of experiments were conducted during 1994 and 1995 at Swift Current, Saskatchewan, Canada to evaluate forage production and animal performance on tetraploid Kirk (Agropyron cristatum (L.) Gaertn.) and diploid Fairway (Agropyron cristatum (L.) Gaertn.) crested wheatgrass pastures under grazing conditions imposed by beef (Bos taurus) yearling steers at four stock density levels (3, 4, 6 and 8 steers ha-1). Total ungrazed forage production for Kirk was greater (<0.05) than Fairway (6302 kg ha-1 vs. 5235 kg ha-1) in 1994 but less (P<0.05) than Fairway in 1995 (3709 kg ha-1 vs. 4633 kg ha-1). Animal performance (average daily gain, animal grazing days and total animal production) did not differ (P>0.05) for steers grazing either Kirk or Fairway pastures. Plant vigour and available energy reserves following one season of grazing were evaluated through etiolated growth with …

Vertical Distribution In Grass Swards: Interactions Between Dry Matter And Nutritional Quality, D R. Buckmaster, R H. Mohtar, S L. Fales

IGC Proceedings (1977-2023)

A field experiment was conducted to study the distribution of mass and quality over plant height throughout the growing season in a pure stand of orchardgrass (Dactylis glomerata L.). When plant density (expressed as kg DM/ha per cm height) is plotted against a height of strata, all treatments show a similar linear shape distribution. ADF and NDF concentrations declined with sward height. Fall treatments had lower ADF and NDF concentrations than summer treatments. Conversely, CP concentrations showed an increase with plant height. Fall treatments showed higher CP than spring and summer treatments. Defoliation management did not affect orchardgrass quality. …

Application Of The Phygrow Forage Production- Runoff Model For Regional Stocking Analysis, J W. Stuth, J R. Conner, W T. Hamilton, D M. Schmitt

IGC Proceedings (1977-2023)

A hydrologic-based forage production model, PHYGROW, was used to simulate forage production and carrying capacity of a subtropical shrubland complex of over 34 species grazed by various ratios of cattle and goats with a population of indigenous white-tailed deer over a 20-yr simulated weather profile. The diet selection algorithm allowed the three animal populations to selectively graze preferred foods based on preferences of plant species, plant parts, and live:dead status by phenological stage. A level of maximum utilization of key species was specified. An incremental analysis of cattle:goat demand ratio was analyzed to determine how different combinations of livestock were …

Using Nested Paddocks To Study Multiple-Paddock Grazing Systems, B E. Anderson, W W. Stroup, W H. Schacht

IGC Proceedings (1977-2023)

There is insufficient information to guide development of multiple paddock grazing systems. Measuring vegetation responses to grazing period/recovery period intervals is prohibitively expensive when using most grazing research designs. Nested paddock designs reduce land area, number of herds, and number of paddocks needed for comparisons. Nested paddocks permit comparisons of animal performance among whole pasture treatments but comparisons are limited for animal performance differences among grazing/recovery period lengths. Nonetheless, nested paddock designs efficiently document vegetation responses to grazing intervals, which may permit predictions of animal performance.