Agricultural Science Commons^™

Beyond Averages: New Approaches To Understand Heterogeneity And Risk Of Technology Success Or Failure In Smallholder Farming, Bernard Vanlauwe, R. I.C. Coe, Ken E. Giller

All Peer-Reviewed Publications

In recent years, many studies have demonstrated the heterogeneity of the smallholder production environment. Yet agronomic research for development (R4D) that aims to identify and test options for increasing productivity has not consistently adapted its approaches to such heterogeneous conditions. This paper describes the challenges facing research, highlighting the importance of variation in evaluating the performance of soil management recommendations, integrating aspects of production risk management within the formulation of recommendations, and proposing alternative approaches to implement agronomic R4D. Approaches are illustrated using two multi-locational on-farm paired trials, each having one no-input control treatment and a treatment with fertilizer application …

Introduction To Sorghum Paper Production, Zachary Christman

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

Sorghum is a tall grass used for many commercial products such as fodder and syrup. The 10 to 15 feet stalk of the plant has lower lignin than wood and provides a fiber length of 2.31 mm in the outer covering and 1.38 mm for the leaf. Sorghum fiber makes a high quality, strong paper suitable for printing, packaging and paperboard.

Water Permeability/Impermeability In Seeds Of 15 Species Of Caragana (Fabaceae), Dali Chen, Rui Zhang, Carol C. Baskin, Xiaowen Hu

Biology Faculty Publications

Majority legumes in the temperate and arctic zones have water-impermeable seeds (physical dormancy, PY). However, various authors have reported that seeds of some Caragana species are water-permeable and thus non-dormant. We (1) tested seeds of 15 species of Caragana matured in the same site in 2014, 2016 and/or 2017 for presence of PY, (2) determined if dry storage decreased or increased the percentage of seeds with PY and (3) located the site on the seed coat of 11 species where water enters the seed. Sixty-three percent and 45% of the seeds of C. roborovskyi had PY in 2016 and 2017, …

Use Of Annual Forage Mixtures In Crop/Livestock Production Systems In Nebraska, Nathan Paul Pflueger

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

Success of integrating annual forages into crop and livestock systems throughout Nebraska may be variable depending on field location, field/forage crop management, and precipitation. There are many different warm- and cool-season annual forage species available for integrating crop and livestock systems at different times of the year. Mixtures of cereal species, such as oats (Avena sativa)) and spring peas (Pisum sativum)), are often used to optimize forage quantity and forage quality. Our two-year, three location study across Nebraska’s precipitation gradient suggested that forage quantity and quality may vary by location due to different precipitation amounts received …

Effect Of Soil-Applied Protoporphyrinogen Oxidase Inhibitor Herbicides On Soybean Seedling Disease, Nicholas J. Arneson

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

Seedling disease is one the most economically important diseases of soybean in the United States. It is commonly caused by Fusarium spp., Rhizoctonia solani, Pythium spp., and Phytophthora sojae, alone, or together as a disease complex. Fungicide seed treatments continue to provide the most consistent management of seedling diseases. Soil-applied protoporphyrinogen oxidase (PPO) inhibitor herbicides are used preemergence in soybean production to manage several broadleaf weeds. Applications of PPO-inhibitors can result in phytotoxic injury to soybean when environmental conditions are not favorable for soybean growth. These environmental conditions can favor seedling disease development as well. In this thesis, two …

Characterization Of Macrophomina Phaseolina Infecting Chia Plants, Cailyn Sakurai, Hagop S. Atamian, Julien Besnard

Student Scholar Symposium Abstracts and Posters

Microbial organisms have caused detrimental effects to agricultural plants by significantly decreasing their plant growth yield and it’s nutritional qualities, leading to high levels of economic losses in society. Salvia Hispanica L., commonly known as chia, is becoming a rising agricultural crop because of its favorable nutritional qualities. Chia seeds have a high concentration of α-linolenic acid, commonly known as omega-3 fatty acids) which provide several different health benefits, in addition to being a rich source of protein and fiber. Chia field trial conducted by the Atamian lab during summer 2018, experienced high levels of disease incidence characterized by …

Integrated Management Of Phytophthora Stem And Root Rot Of Soybean And The Effect Of Soil-Applied Herbicides On Seedling Disease Incidence, Vinicius Castelli Garnica

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

Soybean seedling diseases and Phytophthora stem and root rot (PSRR; caused by Phytophthora sojae) are two of the most economically important diseases in North Central U.S. Remarkable differences in disease incidence occur each year, which demonstrate that abiotic and biotic factors must interact for disease onset and development. During 2017 and 2018, field studies were conducted to (i) address the efficacy of seed treatment and genetic resistance for PSRR management on soybean population, canopy coverage (CC), and yield, and (ii) investigate potential interactions between pre-emergence (PRE) herbicides and the incidence of seedling diseases in alluvial soils in Nebraska.

Despite …

Dna Barcoding Of Pratylenchus From Agroecosystems In The Northern Great Plains Of North America, Mehmet Ozbayrak

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

Pratylenchus species are among the most common plant parasitic nematodes in the Great Plains Region. The objectives of this study were to barcode Pratylenchus specimens for species identification in the Great Plains region using mitochondrial CO1 DNA barcode. In order to (1) determine species boundaries, (2) assess the host associations of barcoded Pratylenchus, (3) to determine the distribution patterns across the Great Plains Region and, (4) to evaluate the species status of P. scribneri and P. hexincisus by a multivariate morphological analysis of haplotype groups identified by DNA barcoding. Soil samples, primarily associated with eight major crops, were collected …

Establishment Of Perennial Legumes With An Annual Warm-Season Grass As A Companion Crop, Martina N. La Vallie

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

The yields of perennial forage legumes are often hindered during the establishment year due to slow germination rates and weed competition. This study was conducted to determine if sorghum-sudangrass (Sorghum bicolor x S. bicolor var. sudanese) is a compatible annual companion crop for increased forage production, weed suppression, and legume establishment. In 2016, sorghum-sudangrass was paired with alfalfa (Medicago sativa L. ‘Ranger’), birdsfoot trefoil (Lotus corniculatus L.), Illinois bundleflower [Desmanthus illinoensis (Michx.) MacMill. ex B.L. Rob. & Fernald], purple prairie clover (Dalea purpurea Vent.), red clover (Trifolium pratense L.), and roundhead lespedeza (Lespedeza capitata Michx.). We studied effects of a …

Science Communication In Agriculture: The Role Of The Trusted Adviser, Lee Galen Briese

Doctor of Plant Health Program: Dissertations and Student Research

Agronomy is not simply the selling of agricultural products to farmers, nor is it the process of solving singular production problems. Agronomy is defined as the integrated, holistic perspective of agriculture (ASA, 2019) and “agronomists are specialists in crop and soil sciences, as well as ecology” (ASA, 2019). While scientific investigation and discovery are essential to understanding systems function, the tangible benefits from our knowledge stems from the application to solve problems. Clear communication is vital to successfully help stakeholders understand the importance of the science and help scientists understand the challenges stakeholders face. However, to successfully put science into …

A Silicon Germanium Cmos Linear Voltage Regulator For Wireless Agricultural Applications, Aminta Naidili Castillo Robles

Graduate Theses and Dissertations

This thesis presents the design, simulation and test results of a silicon germanium (SiGe) complementary metal-oxide-semiconductor (CMOS) linear regulator. The objective of the circuit is to power other analog devices regardless of the load current and input voltage changes. The application of this regulator is to be part of a project developing a miniaturized semiconductor platform that can be inserted into stems of crops in order to measure data inside the plant and then send it wirelessly to the user. The linear regulator was designed on a BiCMOS SiGe 0.13µm which is a GlobalFoundries process. It has been tested at …

Assessment Of Control Of Ppo-Resistant Palmer Amaranth And Salvage Options In Herbicide-Resistant Cotton, Wyatt D. Coffman

Graduate Theses and Dissertations

Palmer amaranth has been the most limiting weed in cotton production in the state of Arkansas for many years. Recently, resistance of Palmer amaranth to the protoporphyrinogen oxidase (PPO)-inhibiting site of action has been discovered at various locations across the cotton-producing region of the state. Cotton varieties have been developed with resistance to synthetic auxin (WSSA Group 4) herbicides. However, research to date has shown PPO-resistant Palmer amaranth to be more difficult to control with herbicides that target alternative sites of action. Herbicide efficacy is also known to vary with weed size, varying spray parameters, and environmental conditions. Preliminary research …

Modelling Appropriate Use Of Trypanocides To Restrict Wide-Spread Multi-Drug Resistance During Chemotherapy Of Animal African Trypanosomiasis, Ibrahim I. Wangwe, Sarah A. Wamwenje, Caroline Mirieri, Nicodemus M. Masila, Lillian Wambua, Benard W. Kulohoma

All Peer-Reviewed Publications

Trypanocide resistance remains a huge challenge in the management of animal African trypanosomiasis. Paucity of data on the prevalence of multi-drug resistant trypanosomes has greatly hindered optimal veterinary management practices. We use mathematical model predictions to highlight appropriate drug regimens that impede trypanocide resistance development in cattle. We demonstrate that using drugs in decreasing resistance order results in a negligible increase in number of cattle with resistant infection, in contrast to a more pronounced increase from trypanocide use in increasing resistance order. We demonstrate that the lowest levels of trypanocide resistance are achieved with combination therapy. We also show that …

Extraction And Quantification Of Hydrolyzable Tannins In Acorns From Different Species Of Oak Trees (Quercus Spp.), Sarah Browning, Marshall E. Woodruff

Undergraduate Research Conference

Do white-tailed deer (Odocoileus virginianus) prefer to eat certain types of acorns based on tannin content?

Hydrolyzable tannins consist of gallate groups connected via ester linkages to a carbohydrate (D-glucose)

The Prussian Blue method was used to determine hydrolyzable tannin content

Nitrogen Release And Synchrony In Organic And Conventional Farming Systems Of The Central Highlands Of Kenya, Martha W. Musyoka, Noah Adamtey, Else K. Bünemann, Anne W. Muriuki, Edward N. Karanja, Monica Mucheru-Muna, Komi K.M. Fiaboe, Georg Cadisch

All Peer-Reviewed Publications

To match Nitrogen (N) supply to crop N demand, it is essential to understand N release and uptake patterns in different farming systems and crops. To assesses the dynamics of N released in organic and conventional systems and potential synchrony and asynchrony in crop N uptake, a study was conducted over three cropping seasons (potato, maize and leafy vegetables) at two sites in the Central Highlands of Kenya. Mineral-N release and synchrony were monitored in conventional and organic systems at high (recommended N, P, pesticides and irrigation) and low input (low N, P, pesticide use and rainfed) systems. Mineral-N release …

Pengaruh Pupuk Organik Tandan Kosong Kelapa Sawit Terhadap Pertumbuhan Dan Kualitas Bunga Seruni, Libria Widiastuti, Tri Pamujiasih, Srie Juli Rachmawatie

Jurnal Kultivasi

Seruni merupakan tanaman bunga yang paling banyak dibudidayakan di Indonesia dalam lima tahun terakhir, baik untuk pasar domestik maupun ekspor. Tingginya permintaan bunga potong menuntut pula tingginya kualitas bunga. Salah satu upaya yang dapat dilakukan adalah dengan pemberian pupuk organik tandan kelapa sawit (TKS) pada media tanam untuk pemenuhan nutrisi dan perbaikan media tanam. Tujuan penelitian ini adalah mempelajari efek interaksi varietas dan macam pupuk organik tandan kosong kelapa sawit terhadap pertumbuhan dan kualitas bunga pada tanaman seruni. Penelitian ini dilaksanakan pada bulan Juli sampai Oktober 2018 di Setiya Aji Flower Farm Bandungan Semarang Jawa Tengah dengan ketinggian tempat 800 …

Partisi Bahan Kering Bibit Kopi Arabika (Coffea Arabica L.) Yang Diberi Asam Humat Dan Pupuk Npk Tablet, Santi Rosniawaty, Rija Sudirja, Mira Ariyanti, Syariful Mubarok, Rachmad Akbar

Jurnal Kultivasi

Kopi merupakan salah satu produk perkebunan penghasil devisa negara. Saat ini tanaman kopi menjadi andalan beberapa daerah di Indonesia dengan kekhasannya. Namun demikian produksi kopi masih perlu ditingkatkan karena masih tidak sesuai dengan potensi produksi. Peningkatan produksi kopi dapat diawali dari pembibitan. Pengelolaan bibit yang baik dapat dilakukan dengan pemberian pupuk NPK tablet dan asam humat, yang nantinya akan mempengaruhi fotosintesis dan fotosintat yang dihasilkan. Tujuan penelitian adalah untuk melihat partisi bahan kering bibit kopi melalui bobot kering bagian-bagian tanaman pada bibit kopi yang diberi NPK tablet dan asam humat. Percobaan dilakukan di bulan Februari 2017 sampai bulan April 2017 …

Chemical Free Edible Flowers, Elise Abbott

Scholars Week

Nature is equipped with all the right systems and services in order to be self sustaining. But in the global flower industry, growers are battling insect infestations like never before because of stricter import laws by the United States Department of Agriculture. In order to ensure the processing of their flowers, growers douse them in pesticides making them inedible and harmful to those who work with them. As edible flowers are making their way into the market on cakes and desserts, fresh salads, specialty spreads and much more it's imperative that they are grown in a sustainable and safe manner. …

Perbaikan Keragaan Bibit Jeruk Pamelo Tanpa Biji Dengan Strangulasi Dan Aplikasi Beberapa Dosis Dari Dua Zpt Bap Dan 2,4-D, Wahyu Fikrinda, I Made Indra Agastya

Jurnal Kultivasi

Pamelo memiliki prospek yang baik untuk dikembangkan karena buahnya berukuran besar dan memiliki rasa yang segar. Tujuan penelitian ini adalah mempelajari aplikasi strangulasi dan ZPT terbaik dalam merangsang pertumbuhan vegetatif untuk perbaikan keragaan bibit pamelo tanpa biji. Percobaan dilaksanakan pada bulan Maret sampai Juli 2018 di rumah plastik, Laboratorium Agroteknologi, dan Laboratorium Biologi UNITRI, Malang. Rancangan Acak Kelompok (RAK) faktorial dengan dua faktor digunakan pada penelitian ini. Faktor pertama adalah strangulasi ganda dengan jarak antar kawat yang berbeda yaitu 10 cm, dan 15 cm, sedangkan faktor kedua adalah dosis dan jenis zat pengatur tumbuh yang berbeda yaitu tanpa ZPT, BAP …

Pengaruh Asam Humat Dan Pupuk Kandang Sapi Terhadap Pertumbuhan Tanaman Kakao (Theobroma Cacao L.) Belum Menghasilkan Klon Sulawesi 1, Arkan Azis Kusuma, Santi Rosniawaty, Yudithia Maxiselly

Jurnal Kultivasi

Permasalahan tanaman kakao di Indonesia adalah produktivitasnya rendah. salah satu penyebabnya akibat kekurangan nutrisi pada fase tanaman belum menghasilkan TBM. Upaya yang dapat dilakukan adalah memberikan pupuk organik, yaitu asam humat dan pupuk kandang sapi. Percobaan ini bertujuan untuk mengetahui pengaruh macam pupuk organik (asam humat susulan dan pupuk kandang sapi) terhadap pertumbuhan tanaman kakao klon Sulawesi 1 umur 7 bulan setelah tanam. Percobaan dilakukan dari bulan September sampai dengan Desember 2017 di Kebun Percobaan Ciparanje Fakultas Pertanian Universitas Padjadjaran, Jatinangor, Kabupaten Sumedang, Jawa Barat pada ketinggian ± 752 m di atas permukaan laut (dpl). Tipe curah hujan di lokasi …

Soil Responses To Various Farming Systems In Western Kentucky, Samantha Peterson

Scholars Week

The interactions among the farming systems and the soil, water, biota, and atmosphere control the effects of cultivation on soil properties. Land conversion from forest or pasture ecosystems into crop fields altered soil properties due to the loss of soil organic matter (SOM) and the increase of soil compaction. However in Kentucky, the magnitude of the changes varied among the soil properties. Therefore, the objective of this research was to investigate the changes of selected soil properties include SOM, soil pH, and compaction under different crop fields such as corn-soybean-tobacco rotation (Field #1), continuous corn field (Field #2), hemp field …

Evaluating Soil Surface Properties In Two Contrasting Tillage Systems, Riley Mabe, Kaeden Mollett, Marcus Robertson

Scholars Week

Soil properties are affected by tillage practices. Tillage practices that provides an adequate growing environment for crops and maintains good soil structure is crucial. The objective of this study was to compare selected soil properties collected from no-till (NT) and conventional tillage (CT) systems in Kentucky, Indiana, and Illinois. Three undisturbed and three disturbed soil samples were taken from the topsoil at the depth of 0 to 7.5 cm. The samples were analyzed for bulk density (BD), water holding capacity (WHC), field capacity (FC), soil pH, soil organic matter (SOM), and compaction. Bulk density, WHC, and FC of the soil …

Co2 Flux And C Balance Due To The Replacement Of Bare Soil With Agro-Ecological Service Crops In Mediterranean Environment, Emanuele Radicetti, O. Adewale Osipitan, Ali Reza Safahani Langeroodi, Sara Marinari, Roberto Mancinelli

Haskell Agricultural Laboratory (Northeast Research and Extension Center)

Intensive agriculture practices often results in decomposition of organic matter, thus causing soil CO₂ emissions. Agro-ecological service crop could be profitably cultivated to improve soil characteristics and reduce CO₂ emissions under Mediterranean environment. Two-year field trials were conducted in central Italy. The treatments were three agro-ecological service crops (hairy vetch, oat, and oilseed rape) and a no-service cover. Plant development, soil characteristics, and CO₂ emissions were measured. Oat and oilseed rape showed a rapid growth, while hairy vetch started to grow rapidly only after the cold period. Soil CO₂ emissions trend was similar among the agro-ecological …

Flowering, Drought, And Disease Tolerance, And Landscape Performance Of Landscape Rose Grown Under Low-Input Conditions In North Central Texas, Derald A. Harp, Gaye Hammond, David C. Zlesak, Greg Church, Mark Chamblee, Steve George

Faculty Publications

Landscaping today involves the struggle to balance aesthetically pleasing plants while minimizing the impact on the environment, reducing water usage, decreasing fertilizer use, and eliminating or significantly reducing pesticide usage. Roses (Rosa sp.), although seen as challenging plants, remain the most popular flowering shrub in the United States. The identification of new cultivars that combine beauty, pest and disease resistance, and drought tolerance are important to Texas landscapes. Sixty roses were assessed over a 3-year period to determine flowering, drought tolerance, disease resistance, and overall landscape performance in minimal-input gardens in north central Texas. Atypical weather during the study …

Río Muchacho: La Interacción Entre Agricultura Orgánica, Educación Ambiental Y Ecoturismo, Tatum Contreras

Independent Study Project (ISP) Collection

El enfoque principal de mi proyecto fue crear un documental sobre cómo Río Muchacho combinada lo orgánico, el ecoturismo y la educación ambiental. Hice mi proyecto en la provincia de Manabí cerca del pueblo Canoa. Documenté y entrevisté a todas las personas involucradas en Río muchacho- de los dueños, a los visitantes. Empecé mi proyecto el 8 de abril y terminé con la filmación y las entrevistas el 26 de abril. En la primera semana trabajé en la finca orgánica de 7 de la mañana hasta las 4 de la tarde. Las dos otras semanas trabajé de 7 a la …

Regenerative Grazing And The Benefits Of Livestock On Soils In Northern New South Wales, Raymond Mooney

Independent Study Project (ISP) Collection

Conventional cattle grazing has received criticism for environmental degradation in the past. Regenerative grazing and the principles of regenerative agriculture show encouraging signs that proper livestock management and planned grazing can reverse degradation and mitigate climate change. An emphasis on soil health and increasing soil carbon and organic matter levels reveals positive feedback for environmental health, the economic security of farmers, and nutritional health of consumers.

In this study I looked to investigate the benefits of regenerative agriculture, reasons why it is being practiced, and the extent it is practiced within the grazing in comparison to traditional methods within Northern …

Genome-Wide Association Studies In Maize And Sorghum, Preston Hurst

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

Genome-wide association studies are used to identify genetic variants associated with a particular phenotype. GWAS has been used in a variety of taxa, from humans, to fish to plants . The present analysis is focused on two species important to the human species: maize and sorghum. A GWAS in maize was carried out on the modification of the Ga1-s allele. The Ga1 locus has long been studied as being involved in a unilateral crossing barrier . However, it has long been suspected that the locus is modified by background genetic factors . GWAS was used to observe candidates for this …

Defining, Measuring, And Applying Soil Quality: An Unresolved Debate, Salvador Ramirez Ii

Doctor of Plant Health Program: Dissertations and Student Research

Paradigm shifts occur periodically in the sciences. Proposed paradigm shifts offer opportunities to reexamine extant paradigms and evaluate new ones. Soil science experienced a controversy resembling a proposed paradigm shift in the late 1990s and early 2000s when it grappled with the idea of soil quality (SQ). The most contentious points in the SQ debates were (1) the word “quality” itself and designing a functional definition, (2) identifying appropriate soil quality indicators, (3) the integration of soil quality indicators, and (4) the interpretation of soil quality indicators. The latter three disagreements were rooted in the established, fundamental, soil science paradigm. …

Nutrient Management Suggestions For Corn, Charles A. Shapiro, Richard Ferguson, Charles S. Wortmann, Bijesh Maharjan, Brian T. Krienke

Department of Agronomy and Horticulture: Faculty Publications

Fertilizer nutrient requirements for corn are based on expected yield and soil nutrient availability. The preplant nitrogen (N) recommendation equation, with adjustment for fertilizer cost and time of application, is retained from the previous edition of this publication. Suggestions for in-season nitrogen decisions are briefly outlined. The major change is providing a phosphorus (P) recommendation based on yield history with an implied intent to build and maintain soil test P above the critical level, which has not changed.

Learning From The Soil's Memory: Tailoring Of Fertilizer Application Based On Past Manure Applications Increases Fertilizer Use Efficiency And Crop Productivity On Kenyan Smallholder Farms, Samuel Njoroge, Antonius G.T. Schut, Ken E. Giller, Shamie Zingore

All Peer-Reviewed Publications

The large uncertainty in yield response to fertilizer application within smallholder cropping systems in sub-Saharan Africa (SSA) limits efforts aimed at intensifying crop production based on increased fertilizer application. We assessed the key field-scale cause of variability in maize (Zea mays) grain yield response to fertilizer nitrogen (N), phosphorus (P) and potassium (K) in the Sidindi area of Western Kenya based on past manure application, distance from the homestead, and clay and silt contents. We used data from nutrient omission trials conducted on 23 farms over seven consecutive cropping seasons covering the period 2013–2016, without changing treatments or plot location. …