Agronomy and Crop Sciences Commons^™

Push-Pull Farming System Helps Insure Smallholder Maize Production Under Climate Change, Yann Clough, Wilhelm May, Timothy Luttermoser, Dickens Nyagol, Nikolaos Alexandridis, Frank Chidawanyika, Mattias Jonsson, Charles A.O. Midega, Katja Poveda, Zeyaur R. Khan

All Peer-Reviewed Publications

Agroecological approaches harnessing in-field biodiversity have been highlighted as a sustainable way to reduce yield gaps, but long-term assessments of their ability to buffer production from weather extremes and increasing interannual and intraseasonal climate variability are scarce. Here, we analyze a 12-year dataset from 642 control vs. push-pull maize field pairs in western Kenya, where long-term climate trends include increasing temperatures and intensifying drought and rainfall. In push-pull, maize is intercropped with a fodder legume that improves soil fertility, suppresses weeds, and deters pests, and is bordered with fodder grasses attracting and suppressing the pests. We assess interactions between push-pull …

Collecting Holistic Evidence On Agroecology Performance To Accelerate Sustainable Food System Transitions, Sarah K. Jones, Andrea Cecilia Sánchez, Chris Dickens, Matthias S. Geck, Chaturangi Wickramaratne, Veronique Alary, Peter Bolo, Dennis Junior Choruma, Somphasith Douangsavanh, Modou Gueye Fall, Gatien Falconnier, Shweta Gupta, Chris Kettle, Smitha Krishnan, Sylvia Nyawira, Guillermo Orjuela-Ramirez, Boko Michel Orounladji, Piedad Pareja, Telma Sibanda, Christine Lamanna

All Peer-Reviewed Publications

A growing body of research shows the potential of agroecology for enabling a shift to planet-friendly and socially just agrifood systems through context-specific transition pathways. We conduct a scoping review to identify and evaluate the potential of 42 existing agroecology adherence and/or agricultural performance assessment tools to generate credible, legitimate, salient and transferable evidence to inform these transitions. Results show that while multiple relevant tools exist, each of them can be strengthened in at least one area. While most tools are transferable (low time and resource requirements) and have legitimacy (open access with transparent methods), tools have variable saliency (holistic …

Performance Of The Denitrification-Decomposition Model In Simulating Agronomic Properties And N2o Emissions Under Smallholder Climate-Smart Farming Systems, Esphorn Kibet, Collins M. Musafiri, Milka Kiboi, Onesmus K. Ng'etich, David K. Kosgei, Abdirahman Zeila, Franklin Mairura, Felix K. Ngetich

All Peer-Reviewed Publications

The DeNitrification-DeComposition (DNDC) model is a crucial tool for estimating soil greenhouse gas fluxes and understanding soil-plant interactions. This study evaluates the performance of the DNDC model in simulating soil temperature, moisture, crop yield, and nitrous oxide (N2O) fluxes across different land utilization types in Western Kenya. The land utilization types included: i) agroforestry M (agroforestry with Markhamia lutea, ii) sole sorghum, iii) agroforestry L (agroforestry with Leucaena leucocephala), iv) sole maize, and v) grazing Land, each replicated thrice. Fertilizer and manure were applied as part of the management practices, with manure applied at 2t ha⁻¹. Soil greenhouse …

Exploring Regenerative Vegetable Systems On The Central Coast Of California, Una S. O'Connell

Master's Theses

As climate change and current agricultural practices place pressure on the long term sustainability and resilience of food production systems, there is growing interest in whether existing agricultural systems can adapt to maintain productivity while improving environmental outcomes.

This study evaluated the effects of regenerative versus standard organic vegetable production systems on yield, insect communities, and weed suppression across three field trials conducted on California's Central Coast. In addition, I collected baseline soil health data for all trials. Trials 1 and 2 were carried out at the Cal Poly San Luis Obispo Organic Farm using cabbage and broccoli as cash …

Evaluating Soil Health And Crop Yield In Louisiana Agricultural Systems: Impacts Of Best Management Practices And Prediction Models, Hector J. Mendoza Lagos

LSU Doctoral Dissertations

The adoption of conservation management practices is critical for improving soil health, enhancing nutrient use efficiency, and sustaining crop productivity in row crop systems in Louisiana. This study evaluated the role of conservation agronomic practices, soil biochemical indicators, and machine learning predictive models to improve soil nutrient dynamics, soil health indicators, microbial communities (MC), and crop productivity on a corn (Zea mays L.) research plot scale and in a commercial forty-hectare cotton (Gassypium hirsutum L.)-corn-soybean (Glycine max L.) rotation system in northeast Louisiana. The objectives of the study were to evaluate soil nutrient dynamics and MCs under …

To Hold Or Sell Breeding Cattle In The Rangelands, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

In a dry season where feed, water and finances are limited, removing less productive animals as soon as possible is a good option. This will free up feed for more productive animals and help preserve ground cover.

This page provides some of the information and a process for making decisions about holding or selling breeding cattle.

Micronutrients (Trace Elements) For High Rainfall Pastures In Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Micronutrient deficiencies can result from removal of agricultural products over many years, changes in soil acidity, or from large increases in plant biomass production and export. This page is specific to high rainfall pastures (more than 600mm average annual rainfall) in the south-west of Western Australia.

The Department of Primary Industries and Regional Development recommends tissue testing to check plant micronutrient nutrient needs.

Potassium For High Rainfall Pastures In Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Potassium (K) deficiency can lead to a decline in clover content and severely limit pasture productivity in high rainfall pastures. Large amounts of potassium can be lost each year through leaching and removal of potassium in hay or silage.

This information is specific to high rainfall pastures receiving more than 600mm average annual rainfall in the south-west of Western Australia.

Soil Sampling High Rainfall Pastures In Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Soil sampling and testing is an essential part of making good fertiliser decisions. Fertilisers are a large cost to farming pastures in high rainfall areas. This page is specific to sampling high rainfall pastures (more than 600mm average annual rainfall) in the south-west of Western Australia.

The Department of Primary Industries and Regional Development recommends soil sampling and testing as part of a plant nutrient management program.

Sulfur For High Rainfall Pastures In Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Sulfur deficiency can substantially reduce pasture yield on sandy soils, particularly in wet years where the sulfate form of sulfur leaches below the root zone of pasture plants, making it unavailable.

This information applies specifically to high rainfall pastures (over 600mm average annual rainfall) in the south-west of Western Australia.

The Department of Primary Industries and Regional Development recommends basing fertiliser decisions on good evidence (soil and tissue test results)

Tissue Sampling And Analysis For High Rainfall Pastures In Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Tissue testing helps identify nutrient deficiencies that impact plant health. In high rainfall areas ( > 600 mm), pastures are highly productive and have greater demand for both macro- and micronutrients. Micronutrient status is best assessed through plant tissue, as soil levels are difficult to measure accurately.

The Department of Primary Industries and Regional Development recommends tissue testing to assess the effectiveness of fertiliser and soil testing programs, and diagnose emerging macronutrient and micronutrient deficiencies that could cause production losses.

Environmental Impact Of Nitrogen And Phosphorus Fertilisers In High Rainfall Pasture Areas Of Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

The most commonly used nitrogen and phosphorus fertilisers in the high rainfall (>600mm annual average) south-west of Western Australia can be leached into the groundwater and washed into waterways, resulting in serious environmental and economic damage.

The Department of Primary Industries and Regional Development recommends regular soil testing and consultation with FertCare-accredited advisers to reduce leaching losses and increase profit from added nutrients.

Assessment Of Soybean Response To Irrigation Variability In Eastern Nebraska Using The Aquacrop Model, Anmol Singh, Saleh Taghvaeian, Yufeng Ge, Derek M. Heeren, Frank Bai

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Soybean [Glycine max (L.) Merr.] is a major irrigated crop in eastern Nebraska, where recent expansions in irrigated agriculture and projected trends in irrigation demand necessitate thorough investigations of approaches that can optimize its irrigation management. In this study, the AquaCrop model was calibrated and validated using 19 variable irrigation treatments from a five-year field experiment. The model accurately simulated canopy cover, soil water content, and grain yield, with validation normalized root mean square error (nRMSE) of 12%, 7%, and 7%, respectively. The model was subsequently applied to estimate soybean yield and water requirement during a 15-year period (2010–2024) …

An Integrated Modeling Framework To Evaluate Circularity Of The Corn–Water–Ethanol–Beef Nexus, Heydi Han

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

This dissertation examines the transition from conventional linear agricultural and food bioenergy systems toward more circular, resilient, and resource-efficient configurations. Prior research indicates that spatial and temporal variability in soil, weather, animal biological responses, and management decisions strongly influences productivity, nutrient-use efficiency, and profitability. Studies have also shown that a diversified circular system can buffer these sources of variability, improving stability and adaptive capacity. Building on these insights, the central focus of this work is to develop an integrated modeling framework to evaluate circularity within the Corn-Water-Ethanol-Beef (CWEB) nexus and explore how climate variability and management choices shape system-wide performance. …

Assessing Crop Rotation Productivity, Soil Health, And Fertility, And Economic Performance, To Enhance Semi-Arid High Plains Cropping Systems Sustainability, Ezequiel Maria Villamil

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

Sustainable crop production in the semi-arid High Plains of Nebraska faces challenges from limited precipitation, high interannual variability, and economic risk. This dissertation investigates the long-term productivity, water use, soil health, and economic sustainability of dryland crop rotations, with emphasis on the role of pulses as alternatives to fallow.

Chapter 1 analyzes nearly three decades (1995–2023) of on-farm data from the High Plains Agricultural Laboratory (Sidney, Nebraska) to compare seven crop rotations, including wheat, corn, millet, sunflower, and field peas. Results showed that wheat–corn–fallow (W–C–F) consistently outperformed traditional wheat–fallow (W–F) and more intensified four-year rotations, providing the highest grain yields, …

Effect Of Planting Date, Insecticide Efficacy, And Hail Injury On Soybean Gall Midge (Resseliella Maxima Gagné) Infestation In Soybean, Natasha Hiromi Umezu

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

Resseliella maxima Gagné (Diptera: Cecidomyiidae) is a recently described and economically significant pest of soybean (Glycine max (L.) Merr.) in the Midwestern United States. Since its identification in 2019, this species has become widespread and is now associated with substantial yield losses in parts of the region. Prior to its formal description, orange larvae were observed in soybean associated with plants damaged by hail, suggesting that plant injury may influence infestation. Given the pest’s economic importance, understanding the role of hail injury and developing effective, integrated management strategies are critical for mitigating its impact.

Field studies were conducted to …

Identifying Superior Finger Millet (Eleusine Coracana L.) Landraces Using The Multi-Trait Genotype-Ideotype Distance Index (Mgidi), Sujan Chapagaina, Bishnu Prasad Kandela, Sudikshya Shresthaa, Ankur Poudela, Shubh Pravat Singh Yadavb

Extension Publications

Genetic variability and selection are crucial for finger millet breeding programs to maximize genetic gain and productivity. This study evaluated 18 finger millet landraces cultivated in the mid-hills of Nepal, along with ‘Kavre Kodo 2’ as a check variety, assessing 14 agro-morphological traits. The objective was to identify superior finger millet landraces using a multivariate approach based on the multi-trait genotype– ideotype distance index (MGIDI). The experiment was conducted in a randomized complete block design (RCBD) with three replications. Principal component analysis revealed that the first five components collectively accounted for 80.8% of the total variation, reflecting the genetic relatedness …

The Effects Of Plastic Mulch And Irrigation On Hemp Chemistry And Leaf Endophytes, Allison Rietman, Connor Morozumi, Robert C. Pearce, Natalie Christian

Journal of Agricultural Hemp Research

As an emerging crop, cultivation techniques for industrial hemp (Cannabis sativa L.) are still being developed and optimized. For example, irrigation and plastic mulching are some management practices that have been touted for their benefits in improving crop quality. Both techniques ensure ample water availability, which has often been attributed to improving hemp cannabinoid and terpene composition. In this study, we examined how supplemental irrigation implemented in a plastic mulch system influenced the cannabinoid and terpene profiles of one cultivar of CBD hemp, Lifter. We grew industrial hemp in field with plastic mulch and applied regular irrigation to one group …

Western Australian And South Australian Grain Enterprise Emission Intensities And Gross Margins: A Review, Christophe D'Abbadie, Ross Kingwell

Farm Systems and Economics research articles

Drawing on various datasets, crop enterprise emission intensities and gross margins are reported for the main broadacre crops grown in Western Australia and South Australia. Values are reported for various rainfall regions and across time, and for different farm performance groupings. As a generalisation, in each region, wheat and canola production display marked increases in emissions intensity across the study period whilst legume crops’ emission intensities increase far less. Wheat crops display upward emission intensity trajectories across time whilst displaying different rates of increase in emissions intensity according to regional rainfall. Canola demonstrates higher emissions intensities per tonne compared to …

Unraveling Crop Nitrogen-Water Dynamics With Hyperspectral-Thermal Sensing In Northern Central Valley, California, Shahryar Fazli, Surendra Maharjan, Wenzhao Li, Joshua B. Fisher, Rejoice Thomas, Fernando Romero Galvan, Gabriela Shirkey, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Ensuring global food security in the face of climate change requires optimizing crop water use and nutrient management. This study investigates the relationship between canopy nitrogen (N) and evapotranspiration (ET) across sunflower, rice, walnut, alfalfa, and plum crops using advanced remote sensing technologies. High-resolution hyperspectral data from NASAs Earth Surface Mineral Dust Source Investigation (EMIT) and thermal multispectral data from the Landsat-based OpenET system were analyzed over 1,135 km² in California. Regression analysis revealed strong spatial association between canopy N and ET for sunflower (R² = 0.82), rice (R² = 0.71), and walnut (R² = 0.68), …

Soil Health In Nebraska: Exploring Practitioners' Needs And Insights From A Long-Term Organic Farm, Ingrids Isabel Mata Vigil

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

Soil health is foundational to sustainable agriculture, environmental resilience, and long-term food security. Yet, the adoption of soil health assessments remains limited, often perceived as too technical, costly, or difficult to implement in real-world contexts. To better understand these challenges, the first chapter presents findings from a statewide survey of 41 soil health practitioners in Nebraska, including farmers, extension educators, NRCS staff, and conservation professionals. Respondents highlighted the need for simpler, more accessible, and context-specific tools for soil health assessment that help practitioners make informed decisions aligned with their management goals. Complementing these insights, the second chapter includes an independent, …

Response Of Soybean To Variable Irrigation Levels In Eastern Nebraska Using The Aquacrop Model, Anmol Singh

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

AquaCrop was calibrated and validated for soybean [Glycine max (L.) Merr.] using 19 irrigation treatments from five years using data from field experiments. The model accurately simulated canopy cover (CC), soil water content (SWC), and grain yield, with overall validation nRMSE values of 12%, 7%, and 7%, respectively. The overall validation nRMSE for SWC in individual 30-cm soil layers was comparatively higher, at 19%. The model was subsequently applied for long-term simulations (2010–2024) to estimate soybean yield and water requirements for two dominant soil types, Yutan silty clay loam and Tomek silt loam under three irrigation levels - rainfed, …

Mitigating Nitrogen Losses: The Role Of Enhanced Efficiency Fertilizers In Sustainable Corn Production, Dipesh Giri

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

Nitrogen (N) is essential for crop production, but its inefficient use often leads to environmental losses through nitrate leaching, ammonia volatilization, and nitrous oxide (N₂O) emissions. Enhanced efficiency fertilizers (EEFs), such as nitrification inhibitors (NIs) and urease inhibitors (UIs), have been developed to minimize these losses and improve nitrogen use efficiency (NUE). This research combined a multi-year field experiment and a controlled laboratory study to evaluate how dual-inhibitor fertilizers compare to conventional urea and single-inhibitor formulations in Nebraska cropping systems. The main objective was to understand how nitrogen inhibitors influence N availability, crop performance, and nitrogen losses across different environmental …

Extending Cover Crop Growing Window To Improve The Health Of Environmentally Sensitive Soils, Noshin Ara Tunazzina

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

Sloping and sandy soils are highly susceptible to degradation. The health of these soils could be improved with cover crops (CCs). However, CC effectiveness in improving soil health mainly depends on CC biomass production, which is often low in temperate regions. The question is: how can we increase CC biomass production? Lengthening the CC growing window can be a potential strategy. This study assessed how 1) interseeded and terminated early (2-3 weeks before crop planting) CC, 2) interseeded and terminated late (at crop planting) CC, 3) drilled (after harvest) and terminated early CC, 4) drilled and terminated late CC, and …

Landscape Effects On The Beneficial Arthropod Community In Agriculturally Dominated Environments, Hannah E. Stowe

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

Ecosystem services in agriculturally dominated regions rely, at least in part, on arthropods. Environment and biodiversity influence beneficial arthropods in population size, community structure, diversity, and ecosystem service provisioning. Predation is among the most important services provided by arthropods in agroecosystems. Understanding what alters predation and predator activity can support the successful application of biological control and, more broadly, integrated pest management. Land use and edge adjacency, field characteristics, landscape, seasonality, and diel period all alter predatory behavior. Crop fields dominate Nebraska agroecosystems, although interspersed perennial grasslands persist through the Conservation Reserve Program (CRP). Such grasslands supply crucial resources and …

Trenching And Compost Sustain Grain Yield Increases Over Nine Years On Deep Sands But At A Cost, David J.M. Hall, Tom J. Edwards

Grain and Other Field Crops Research Articles

Context. Crops grown on deep sands on the south coast of WA are limited by soil physical and chemical properties including compaction and poor nutrition. Aims. Crops grown on deep sands on the south coast of Western Australia are limited by soil physical and chemical properties including compaction and poor nutrition. Our aim was to determine what effects deep-placed organic amendments have on soil properties and crop production in a deep sand and whether such amendments are profitable. Methods. A long-term field trial was conducted over nine years (2015–2023) to investigate soil amendments including lime (0 and …

Too Much Of A Good Thing: Lessons From Compromised Rootworm Bt Maize In The Us Corn Belt, Ziwei Ye, Christina Difonzo, David A. Hennessy, Jinhua Zhao, Felicia Wu, Shawn P. Conley, Aaron J. Gassmann, Erin W. Hodgson, Bryan Jensen, Janet J. Knodel, Bradley Mcmanus, Lance J. Meinke, Andrew Michel, Bruce Potter, Nicholas J. Seiter, Jocelyn L. Smith, Joseph L. Spencer, Kelley J. Tilmon, Robert J. Wright, Christian H. Krupke

Department of Entomology: Faculty Publications

Widespread use of genetically engineered maize targeting the corn rootworm complex (Diabrotica species) has raised concerns about insect resistance. Twelve years of university field trial and farm survey data from ten United States Corn Belt states indicate that maize hybrids expressing toxins derived from the bacterium Bacillus thuringiensis (Bt maize) exhibited declining protection from rootworm feeding with increased planting while pest pressures simultaneously decreased. The analysis revealed a tendency to overplant Bt maize, leading to substantial economic losses; this was particularly striking in eastern Corn Belt states. Our findings highlight the need to go beyond the “tragedy of the …

An Economic And Production Analysis Of Seaweed Farms In California And The Pacific Northwest, Brian Donovan

Cal Poly Humboldt theses and projects

Since the early 2010s, the seaweed aquaculture industry has steadily expanded in the United States, with states like Alaska, Maine, Hawaii, and Connecticut leading the way in the development of this emerging sector. However, information gaps remain concerning certain aspects of the domestic seaweed aquaculture industry. The purpose of this study was to examine the status of the seaweed aquaculture industry along the West Coast of the United States; specifically in the states of California, Oregon, and Washington. Seaweed farmers in these states were invited to voluntarily complete surveys asking important production, economic, and commercial questions regarding their operations. Data …

Effects Of Round-Up On The Environment, Sandra J. Marcu

Journal of Earth and Life Science

Many people around the world have used and still currently use Roundup but are unaware of the effects it has on the environment. Roundup is a spray on application weedkiller that is widely used around the world today both residentially and commercially. It enables its user to grow a garden or a field of crops with a no-tilling approach to eliminate weeds. It is a well-known and popular choice for killing weeds that has been around since the mid 1970’s (Oca, 2017). John Franz, a Monsanto scientist discovered that glyphosate (main ingredient in Roundup) was an herbicide or weedkiller, and …

Rice Response To Struvite And Other Phosphorus Fertilizers In A Phosphorus-Deficient Soil Under Simulated Furrow-Irrigation, Jonathan B. Brye, Diego Della Lunga, Kristofor R. Brye

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Wastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH₄PO₄⋅6H₂O), may provide a sustainable alternative to decreasing rock-phosphate reserves. Struvite can be generated via precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice (Oryza sativa) cultivar grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)]. Rice was …