Open Access. Powered by Scholars. Published by Universities.®

Agronomy and Crop Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

6767 Full-Text Articles 7043 Authors 630590 Downloads 46 Institutions

All Articles in Agronomy and Crop Sciences

Faceted Search

6767 full-text articles. Page 1 of 119.

Characterization Of Ground Nozzles For Pesticide Applications, Ryan Henry 2016 University of Nebraska - Lincoln

Characterization Of Ground Nozzles For Pesticide Applications, Ryan Henry

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Pesticide applications are a common component of crop production systems in the United States (US). For row crop systems (e.g. corn, soybean, or wheat), pesticides are applied by ground, aerial, or chemigation methods. The exact method of pesticide delivery is not universally regulated/ prescribed in the US, and the equipment and application technique are largely defined by the individual applicator. A wide variety of choices and decisions must be made by applicators to result in a successful pesticide application. Examples of these choices include proper active ingredient(s), carrier volume and equipment (e.g. nozzle type, spacing, and operating ...


Winter Desiccation Prevention And Recovery In Turfgrass, Darrell James Michael 2016 University of Nebraska-Lincoln

Winter Desiccation Prevention And Recovery In Turfgrass, Darrell James Michael

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Desiccating winters in the Northern Great Plains can lead to widespread turf death. This loss of turf results in poor aesthetics and can be financially burdensome. Financial implications include the cost of re-establishing turf and the loss of potential revenue from poor playing conditions in the spring which can both be devastating for financial success. The winter of 2013-2014 was particularly devastating, leaving many golf course superintendents re-evaluating their desiccation prevention management plans. There are many prevention practices available to turf managers that vary greatly in affordability, effectiveness, and labor. These prevention practices aim to prevent excessive water loss and ...


Improved Production Systems For Common Bean On Phaeozem Soil In South-Central Uganda, Lance H. Goettsch, Andrew W. Lenssen, Russell S. Yost, Ebby S. Luvaga, Onesmus Semalulu, Moses Tenywa, Robert E. Mazur 2016 Iowa State University

Improved Production Systems For Common Bean On Phaeozem Soil In South-Central Uganda, Lance H. Goettsch, Andrew W. Lenssen, Russell S. Yost, Ebby S. Luvaga, Onesmus Semalulu, Moses Tenywa, Robert E. Mazur

Andrew W. Lenssen

Common bean (Phaseolus vulgaris L.) is the most important grain legume in Uganda. Beans managed under conventional systems range in yield from 500 to 800 kg ha-1, with a yield gap of about 75%. The objective of this study was to compare the productivity and net profitability of four bean cultivars grown under three management systems on Phaeozem soil (Mollisol) in Masaka District, Uganda. The experimental design was a randomized incomplete block in a split-plot arrangement. Management system was the whole-plot factor and included the Conventional Farmer (CFS), Improved Farmer (IFS), and High Input systems (HIS). Management systems differed for ...


Forage Intake And Wastage By Ewes In Pea/Hay Barley Swath Grazing And Bale Feeding Systems, Erin E. Nix, Devon L. Ragen, Janice G. P. Bowman, Rodney W. Kott, Mark K. Petersen, Andrew W. Lenssen, Patrick G. Hatfield, Emily C. Glunk 2016 Montana State University

Forage Intake And Wastage By Ewes In Pea/Hay Barley Swath Grazing And Bale Feeding Systems, Erin E. Nix, Devon L. Ragen, Janice G. P. Bowman, Rodney W. Kott, Mark K. Petersen, Andrew W. Lenssen, Patrick G. Hatfield, Emily C. Glunk

Andrew W. Lenssen

Harvested feed costs, particularly during the winter, are traditionally the highest input associated with a ruminant livestock operation. Although swath grazing has been practiced for over 100 years and literature exists for cattle use of swath grazing, no published results are available on use of swath grazing by sheep. Sixty mature, white-faced ewes were used in a completely randomized design repeated 2 years to evaluate whether feeding method (swath grazed or fed as baled hay in confinement) of intercropped field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) forage affected ewe ADG (average daily gain), forage DMI (dry ...


Impact Of A Corn-Living Mulch Cropping System On Soil C- And N-Dynamics, Chumki Banik, Cynthia Bartel, David A. Laird, Kenneth J. Moore, Andrew W. Lenssen 2016 Iowa State University

Impact Of A Corn-Living Mulch Cropping System On Soil C- And N-Dynamics, Chumki Banik, Cynthia Bartel, David A. Laird, Kenneth J. Moore, Andrew W. Lenssen

Andrew W. Lenssen

Use of a living mulch in a continuous corn cropping system can potentially protect the soil from erosion and increase organic C inputs into the soil thereby enhancing soil quality and facilitating greater harvest corn stover for bio-energy production. The objective of this study is to evaluate soil C- and N-dynamics under a corn-living mulch system that includes a shallow rooted perennial cover crop, strip tillage, and spring burn down. This study hypothesized that a well managed shallow rooted perennial cover crop can improve soil quality by increasing soil C storage and synergistically distributing soil nutrients. Here we report impacts ...


Kenaf Productivity And Morphology. When Grown In Iowa And In Kentucky. Poster Number, Marie Bouguignon, Kenneth J. Moore, Andrew W. Lenssen, Sotirios V. Archontoulis, Ben M. Goff, Brian S. Baldwin 2016 Iowa State University

Kenaf Productivity And Morphology. When Grown In Iowa And In Kentucky. Poster Number, Marie Bouguignon, Kenneth J. Moore, Andrew W. Lenssen, Sotirios V. Archontoulis, Ben M. Goff, Brian S. Baldwin

Andrew W. Lenssen

Natural fibers are a promising alternative to synthetic fibers for reinforcing plastic or other composite materials, or fuel purposes. Kenaf (Hibiscus cannabinus L.), a fiber crop is grown to a limited extent in the U.S. predominantly in the Southern states. Producing kenaf in the Midwestern U.S. could provide a local source of these fibers for use in a number of manufactured products and potentially for use as a biofuel feedstock. The objectives of this study were to: 1) compare the productivity and the morphology of kenaf cultivars ‘Tainung 2’ and ‘Whitten’ when grown in Iowa and Kentucky and ...


Suitability Of Winter Canola (Brassica Napus) For Enhancing Summer Annual Crop Rotations In Iowa, Mary H. Wiedenhoeft, Rafael A. Martinez-Feria, Thomas C. Kaspar, Andrew W. Lenssen 2016 Iowa State University

Suitability Of Winter Canola (Brassica Napus) For Enhancing Summer Annual Crop Rotations In Iowa, Mary H. Wiedenhoeft, Rafael A. Martinez-Feria, Thomas C. Kaspar, Andrew W. Lenssen

Andrew W. Lenssen

Winter canola shows promise as an addition to crop rotations in Iowa. This project determined optimal seeding dates for this cover crop and explored practices to enhance production. It was estimated that the latest Iowa seeding date varies from around August 31 in the north to September 12 in the southeast.


Sheep Grazing Enhances Coarse Relative To Microbial Organic Carbon In Dryland Cropping Systems, Joy L. Barsotti, Upendra M. Sainju, Andrew W. Lenssen, Zach J. Miller, Patrick G. Hatfield 2016 United States Department of Agriculture

Sheep Grazing Enhances Coarse Relative To Microbial Organic Carbon In Dryland Cropping Systems, Joy L. Barsotti, Upendra M. Sainju, Andrew W. Lenssen, Zach J. Miller, Patrick G. Hatfield

Andrew W. Lenssen

Sheep (Ovis aries L.) grazing, a cost-effective method of weed control compared with herbicide application and tillage, may influence soil C fractions by consuming crop residue and weeds and returning C through feces and urine to the soil. We examined the effect of three weed management practices (sheep grazing, herbicide application, and tillage) and two cropping sequences (continuous spring wheat [Triticum aestivum L.] [CSW] and spring wheat-pea [Pisum sativum L.]/barley [Hordeum vulgare L.] mixture hay-fallow [W-P/B-F]) on soil microbial biomass C (MBC), potential C mineralization (PCM), and particulate organic C (POC) in relation to soil organic C (SOC ...


Soybean Response To Drought, Andrew W. Lenssen 2016 Iowa State University

Soybean Response To Drought, Andrew W. Lenssen

Andrew W. Lenssen

Although drought typically is an infrequent occurrence in Iowa, 2012 has been an exception to the rule. Winter, spring and early summer precipitation has been below long-term average, and soybeans in some areas of the state are experiencing periodic water stress due to inadequate available water content in upper soil depths. Farmers have asked whether drought stress early in the season can influence yield if precipitation levels approach long-term average later in the season.


Optimal Agricultural Practices For Growing Kenaf In Iowa, Marie Bouguignon, Kenneth J. Moore, Sotirios V. Archontoulis, Andrew W. Lenssen, Brian S. Baldwin, Danielle Marie Wilson 2016 Iowa State University

Optimal Agricultural Practices For Growing Kenaf In Iowa, Marie Bouguignon, Kenneth J. Moore, Sotirios V. Archontoulis, Andrew W. Lenssen, Brian S. Baldwin, Danielle Marie Wilson

Andrew W. Lenssen

The demand for natural fibers is increasing worldwide due to a growing interest in using renewable sources in place of those derived from petrochemicals. Kenaf (Hibiscus cannabinus L.) is a promising biorenewable resource for natural fibers that has rarely been grown in the Midwest. Literature is abundant about effects of management practices on kenaf productivity and fiber yield, but few studies have evaluated their interactions. The objectives of this study were to: 1) determine management practices leading to optimal kenaf and fiber yield; 2) evaluate stem height, basal diameter, and leaf area index (LAI) over the growing season; and 3 ...


Nitrogen Balance In Response To Dryland Crop Rotations And Cultural Practices, Upendra M. Sainju, Andrew W. Lenssen, Brett L. Allen, William B. Stevens, Jalal D. Jabro 2016 United States Department of Agriculture

Nitrogen Balance In Response To Dryland Crop Rotations And Cultural Practices, Upendra M. Sainju, Andrew W. Lenssen, Brett L. Allen, William B. Stevens, Jalal D. Jabro

Andrew W. Lenssen

Nitrogen balance provides a measure of agroecosystem performance and environmental sustainability by taking into accounts of N inputs and outputs and N retention in the soil. The objective of this study was to evaluate N balance based on N inputs and outputs and soil N sequestration after 7 yr in response to five dryland crop rotations (two 4-yr stacked and two 4-yr alternate-year rotations and one monocropping) and two cultural practices arranged in a split-plot design in the northern Great Plains, USA. Stacked rotations were durum (Triticum turgidum L.)-durum-canola (Brassica napus L.)-pea (Pisum sativum L.) (D-D-C-P) and durum-durum-flax ...


Cover Crop Options And Mixes For The Upper Midwest: Is A Winter Rye Monoculture The Only Option?, Seth Appelgate, Andrew Lenssen 2016 Iowa State University

Cover Crop Options And Mixes For The Upper Midwest: Is A Winter Rye Monoculture The Only Option?, Seth Appelgate, Andrew Lenssen

Andrew W. Lenssen

Winter rye (Secale cereale L.) is the predominant cover crop being planted by corn and soybean farmers in the upper Midwest. Winter rye is an excellent nitrogen scavenger, grows at a lower base temperature than most other potential cover crops, is very winter hardy, accumulates high levels of residue, and decreases soil erosion. In recent years, cover crop companies and different interest groups have been promoting the benefits of cover crop mixes and new cover crop species. Our study was designed to test new cover crop options and cover crop mixes for their performance in corn-soybean systems in the upper ...


Adapted And Non-Adapted Tropical Corn In Central Iowa: 2. Biomass Production And Composition, Pedro A. Infante Posada, Kenneth J. Moore, Sotirios V. Archontoulis, Andrew W. Lenssen, M. Paul Scott 2016 Iowa State University

Adapted And Non-Adapted Tropical Corn In Central Iowa: 2. Biomass Production And Composition, Pedro A. Infante Posada, Kenneth J. Moore, Sotirios V. Archontoulis, Andrew W. Lenssen, M. Paul Scott

Andrew W. Lenssen

Biomass production in the midwestern United States has largely been focused on corn (Zea mays L.) grain for ethanol production and more recently on corn stover for lignocellulosic ethanol. Corn production in this region is profitable and productive. As an alternative to conventional corn, tropical corn genotypes have been evaluated, but mainly for grain production; nevertheless, yields have fallen short of U.S. Corn Belt populations. Tropical corn is the term used for corn coming from tropical regions. Tropical corn has been adapted for early flowering for potential use in breeding programs under central Iowa conditions. Since adapted and non-adapted ...


Adapted And Non-Adapted Tropical Corn In Central Iowa: 1. Development, Growth And Quality Aspect, Pedro A. Infante Posada, Kenneth J. Moore, Sotirios V. Archontoulis, Andrew W. Lenssen, M. Paul Scott, Shuizhang Fei 2016 Iowa State University

Adapted And Non-Adapted Tropical Corn In Central Iowa: 1. Development, Growth And Quality Aspect, Pedro A. Infante Posada, Kenneth J. Moore, Sotirios V. Archontoulis, Andrew W. Lenssen, M. Paul Scott, Shuizhang Fei

Andrew W. Lenssen

Recent research has shown a high theoretical potential for ethanol production based on both stover and grain as sources, using lignocellulosic and fermentation processes respectively. Corn germplasm has been even broadly studied for grain production, but scant research has been done on current commercial cultivars in regards to biomass production. However, tropical corn germplasm, corn conventionally grown in tropical regions, has been studied as a potential source for biomass accumulation over grain. The comparison between tropical and temperate corn with a focus on biomass production has not yet been explored under Iowa day-length conditions.

This study identifies the adaptability of ...


Cover Crop Options And Mixes For The Upper Midwest: Is A Winter Rye Monoculture The Only Option?, Seth Appelgate, Andrew Lenssen 2016 Iowa State University

Cover Crop Options And Mixes For The Upper Midwest: Is A Winter Rye Monoculture The Only Option?, Seth Appelgate, Andrew Lenssen

Andrew W. Lenssen

Winter rye (Secale cereale L.) is the predominant cover crop being planted by corn and soybean farmers in the upper Midwest. Winter rye is an excellent nitrogen scavenger, grows at a lower base temperature than most other potential cover crops, is very winter hardy, accumulates high levels of residue, and decreases soil erosion. In recent years, cover crop companies and different interest groups have been promoting the benefits of cover crop mixes and new cover crop species. Our study was designed to test new cover crop options and cover crop mixes for their performance in corn-soybean systems in the upper ...


Corn (Zea Mays L.) Seeding Rate Optimization In Iowa, Usa, Mark A. Licht, Andrew W. Lenssen, Roger W. Elmore 2016 Iowa State University

Corn (Zea Mays L.) Seeding Rate Optimization In Iowa, Usa, Mark A. Licht, Andrew W. Lenssen, Roger W. Elmore

Andrew W. Lenssen

Collecting soil, topography, and yield information has become more feasible and reliable with advancements in precision technologies. Combined with the accessibility of precision technologies and services to farmers, there has been increased interest and ability to make site-specific crop management decisions. The objective of this research was to develop procedures to optimize corn seeding rates and maximize yield using soil and topographic parameters. Experimental treatments included five seeding rates (61 750; 74 100; 86 450; 98 800; and 111 150 seeds ha−1) in a randomized complete block design in three central Iowa fields from 2012 to 2014 (nine site-years ...


Cover Crop Options And Mixes For The Upper Midwest: Is A Winter Rye Monoculture The Only Option?, Seth Appelgate, Andrew Lenssen 2016 Iowa State University

Cover Crop Options And Mixes For The Upper Midwest: Is A Winter Rye Monoculture The Only Option?, Seth Appelgate, Andrew Lenssen

Andrew W. Lenssen

Winter rye (Secale cereale L.) is the predominant cover crop being planted by corn and soybean farmers in the upper Midwest. Winter rye is an excellent nitrogen scavenger, grows at a lower base temperature than most other potential cover crops, is very winter hardy, accumulates high levels of residue, and decreases soil erosion. In recent years, cover crop companies and different interest groups have been promoting the benefits of cover crop mixes and new cover crop species. Our study was designed to test new cover crop options and cover crop mixes for their performance in corn-soybean systems in the upper ...


Development Of Transformational Strategies Of Smallholders Based On Indigenous Knowledge, Mark E. Westgate, Lorna Michael Butler, Robert E. Mazur, Andrew W. Lenssen 2016 Iowa State University

Development Of Transformational Strategies Of Smallholders Based On Indigenous Knowledge, Mark E. Westgate, Lorna Michael Butler, Robert E. Mazur, Andrew W. Lenssen

Andrew W. Lenssen

This presentation will outline a few of the key lessons learned during the first 12 years of extension programs implemented by the Center for Sustainable Rural Livelihoods (now the Iowa State University – Uganda Program, a Ugandan NGO). These lessons and recommendations are described in greater detail in “Tapping Philanthropy for Development”, L.M Butler and D. E McMillan (eds), Kumarian Press 2015. Adhere to the Sustainable Livelihoods Approach.The CSRL initiative was developed to identify ways to improve the livelihoods of small landholder famers in rural communities of a developing country. Uganda was chosen because the vast majority of the ...


A Genome-Wide Survey Of Highly Expressed Non-Coding Rnas And Biological Validation Of Selected Candidates In Agrobacterium Tumefaciens, Keunsub Lee, Xiaoqiu Huang, Chichun Yang, Danny Lee, Kan Nobuta, Jian-Bing Fan, Kan Wang 2016 Iowa State University

A Genome-Wide Survey Of Highly Expressed Non-Coding Rnas And Biological Validation Of Selected Candidates In Agrobacterium Tumefaciens, Keunsub Lee, Xiaoqiu Huang, Chichun Yang, Danny Lee, Kan Nobuta, Jian-Bing Fan, Kan Wang

Xiaoqiu Huang

Agrobacterium tumefaciens is a plant pathogen that has the natural ability of delivering and integrating a piece of its own DNA into plant genome. Although bacterial non-coding RNAs (ncRNAs) have been shown to regulate various biological processes including virulence, we have limited knowledge of how Agrobacterium ncRNAs regulate this unique inter-Kingdom gene transfer. Using whole transcriptome sequencing and an ncRNA search algorithm developed for this work, we identified 475 highly expressed candidate ncRNAs from A. tumefaciens C58, including 101 trans-encoded small RNAs (sRNAs), 354 antisense RNAs (asRNAs), 20 5′ untranslated region (UTR) leaders including a RNA thermosensor and 6 ...


Identification Of Highly Variable Supernumerary Chromosome Segments In An Asexual Pathogen, Xiaoqiu Huang, Anindya Das, Binod B. Sahu, Subodh K. Srivastava, Leonor F. S. Leandro, Kerry O'Donnell, Madan K. Bhattacharyya 2016 Iowa State University

Identification Of Highly Variable Supernumerary Chromosome Segments In An Asexual Pathogen, Xiaoqiu Huang, Anindya Das, Binod B. Sahu, Subodh K. Srivastava, Leonor F. S. Leandro, Kerry O'Donnell, Madan K. Bhattacharyya

Xiaoqiu Huang

Supernumerary chromosome segments are known to harbor different transposons from their essential counterparts. The aim of this study was to investigate the role of transposons in the origin and evolution of supernumerary segments in the asexual fungal pathogen Fusarium virguliforme. We compared the genomes of 11 isolates comprising six Fusarium species that cause soybean sudden death syndrome (SDS) or bean root rot (BRR), and identified significant levels of genetic variation in A+T-rich repeat blocks of the essential chromosomes and in A+T-neutral regions of the supernumerary segments. The A+T-rich repeat blocks in the essential chromosomes were highly variable ...


Digital Commons powered by bepress