Agronomy and Crop Sciences Commons^™

Strategies To Mitigate Seasonality Of Production In Grassland-Based Systems, Claudio Porqueddu, S. Maltoni, John G. Mcivor

IGC Proceedings (1977-2023)

Key points

1. Fertilisation use and manipulation can cost-effectively alter species composition, increase seasonal herbage production and improve herbage quality.

2. Choice of suitable grassland species, varieties and mixtures offers opportunity to mitigate limitations of seasonal grassland production.

3. Special purpose fodder crops, cereals, shrubs and trees offer alternative or supplementary feed sources.

4. Manipulation of stocking rates, grazing systems, transhumance and pasture management at various times of the season are significant advantageous options.

5. Integration of different strategies is essential to mitigate seasonality in systems of animal production that must be inherently more sustainable over a longer time frame.

Interactions Between Foraging Behaviour Of Herbivores And Grassland Resources In The Eastern Eurasian Steppes, Deli Wang, Guodong Han, Yuguang Bai

IGC Proceedings (1977-2023)

Key points

1. In rangeland areas such as the eastern Eurasian steppes (Mongolia and China), foraging behaviour is influenced by plant or vegetation properties with high heterogeneity.

2. Until recently foraging theory has not accounted for the foraging process or ingestive behaviour. Existing theories on foraging behaviour need to evolve and begin to coalesce, and combine with observations or manipulative experiments.

3. Plant and patch properties such as diversity and height influence animal foraging behaviour (related to foraging process or diet selection) in heterogeneous steppes.

4. Stocking rate is the most important management factor for grazing or vegetation management, and …

Foraging Behaviour And Herbage Intake In The Favourable Tropics/Subtropics, S. C. Da Silva, Paulo C. De F. Carvalho

IGC Proceedings (1977-2023)

Key points

1. Herbage intake by animals grazing tropical/sub-tropical pastures is directly related to bite mass, as it is for those grazing temperate pastures.

2. Where these swards have low proportions of stem and dead material (controlled swards), herbage intake follows a similar pattern to that of temperate pasture species, but leaf characteristics, such as lamina length play an important role and influence the short-term rate of intake.

3. Sward structural characteristics and behavioural factors are relatively more important than nutritional factors in terms of herbage intake regulation. The feeding value of the herbage produced is potentially adequate to sustain …

Grass And Forage Plant Improvement In The Tropics And Sub-Tropics, Liana Jank, Cacilda B. Do Valle, Rosangela M. S. Resende

IGC Proceedings (1977-2023)

Key points

1. The majority of tropical and subtropical forage grass genera and/or species have not yet been collected, or need further collection to be representative of their natural distribution.

2. New biotechnological techniques will only result in the release of superior forage cultivars if supported by strong breeding programs.

3. More funding and investment in the formation of strong public research teams in forage conservation and improvement are needed to guarantee the sustainability of tropical and subtropical pasture-based livestock systems in the future.

4. The creation of a permanent international working group on tropical and subtropical forages is essential …

Grass And Forage Improvement: Temperate Forages, Chris J. Pollock, M. T. Abberton, M. O. Humphreys

IGC Proceedings (1977-2023)

Key points

1. Plant breeding has contributed significantly to the development of effective grassland production systems.

2. New technologies offer enhanced precision in breeding and access to wider genetic variation.

3. The requirement for more sustainable production systems will require genetic improvements in complex traits where the use of new technology will be vital.

Improving The Quality Of Products From Grassland, Nigel D. Scollan, R. J. Dewhurst, A. P. Moloney, J. J. Murphy

IGC Proceedings (1977-2023)

Key points

1. Consumers are increasingly aware of the links between diet and health, and place increasing emphasis on nutritional quality as a component of product quality.

2. Meat and milk products are rich sources of nutrients such as omega-3 (n-3) fatty acids and conjugated linoleic acid, which offer health benefits to consumers.

3. Green plants are the primary source of n-3 fatty acids in the food chain.

4. Grassland production systems have the potential to enhance the content of beneficial fatty acids, improve stability (from higher antioxidant content) and alter sensory attributes of meat and milk.

5. Grassland offers …

Rising Demand For Meat And Milk In Developing Countries: Implications For Grasslands-Based Livestock Production, C. L. Delgado

IGC Proceedings (1977-2023)

Key points

1. Meat and milk consumption in developing countries has grown three times as fast as in developed countries over the past 30 years.

2. By 2020, developing countries will consume 72 million metric tons (mmt) more meat and 152 mmt more milk compared to 2002/3, dwarfing developed-country increases of 9 mmt for meat and 18 mmt for milk.

3. Ruminant livestock will account for 27% of the increase in global meat consumption between 2003 and 2020, up from 23% over the previous two decades.

4. The inflation-adjusted prices of livestock and feed grains are expected to fall only …

Grassland In Ireland And The Uk, Myles Rath, S. Peel

IGC Proceedings (1977-2023)

Key points

1. Grassland is the dominant land use option in Ireland and the UK, and is characterised by a long growing season.

2. Dynamic, interactive systems of grassland management have been developed which combine high grass dry matter intakes with good sward quality. In the better grassland areas milk yields in excess of 7000 kg/cow are attainable with low levels of concentrate supplementation.

3. In the times to come, measures to protect the environment will constrain stocking rates, and fertiliser and manure use on intensive grassland enterprises.

4. A high proportion of beef and sheep farms participate in voluntary, …

Influence Of Fertilizer Rate On Swollen Stem Formation (“Bulbing”) And Vitamin C Content In Different Kohlrabi Cultivars, Mark Iradukunda, Paul E. Read

Honors Program: Senior Projects (Public)

Kohlrabi (Brassica oleracea Gongylodes Group) is a vegetable crop found in the Brassicaceae, and it is rich in antioxidants such as vitamin C. Vitamin C helps in oxidative damage repair and strengthens the immune system, so exploring vitamin C sources may contribute to improving human health. The objective of this study was to determine the effect of different fertilizer rates on kohlrabi yield, in terms of the swollen stem and the vitamin C content, and if those effects are similar in different kohlrabi cultivars. In this greenhouse study, we fertilized four potted kohlrabi cultivars with a common water-soluble greenhouse fertilizer …

No-Till Farming And Greenhouse Gas Fluxes: Insights From Literature And Experimental Data, S. J. Ruis, H. Blanco-Canqui, P. J. Jasa, V. L. Jin

Department of Agronomy and Horticulture: Faculty Publications

Tillage intensity may differently impact gaseous losses of C and N to the atmosphere, but data from long-term experiments are relatively few. Yet, this information is needed to better understand C and N losses and gains in agricultural systems. The objective of this study was to determine how tillage intensity affects soil greenhouse gas (GHG) fluxes (CO₂, N₂O, and CH₄) by comparing experimental data from moldboard plow (MP), chisel plow (CP), double disk (DD), and no-till (NT) soils after 38–40 yr of management in a rainfed corn (Zea mays L.)- soybean (Glycine …

Modeling The Dynamics Of Soil Organic Matter Accumulation From Leaf Litterfall As Affected By Tillage Practices In Mango Orchard, Fernan T. Fiegalan, Cherry L. Ringor, Tolentino B. Moya

The Philippine Agricultural Scientist

This study was undertaken to determine long-term soil organic matter (SOM) accumulation dynamics from added mango leaf litter (MLL) into tilled (MT) and non-tilled soil (MnT) through integrated field experiment (bio-physico-chemical edaphic properties) and system dynamics modeling. Field data shows that the coarse (Lf) and fine (Fn) fractions of SOM have no significant difference (p > 0.05) between MT and MnT during the dry season. In contrast, there is a significant difference (p < 0.01) in the Fn fraction between MT and MnT during the wet season. The total N, available P, exchangeable K, as well as the collembola, bacteria, and fungi in the soil were also assessed. Of these parameters, the available P and exchangeable K have a significant difference between the MnT and MT during the dry season. In comparison, the total N and collembola significantly differed during the wet season. The results of the field experiment were used in the parametrization to build the SOM accumulation model. The 20-year simulation showed that the incorporation of MLL into the soil through tillage increased SOM from 3.09% to 3.13%, with an average of 2.78 ± 0.018%. In the non-tilled orchard, SOM also increased from 3.09% to 4.23%, with an average of 3.59 ± 0.035%. This SOM level can sustain the fertility and productivity of the mango agroecosystem. The increase in SOM is accounted for by the coarse fraction both in tilled and non-tilled plots. Given the foregoing, with minimum tillage, mango orchards can be developed into crop-based systems.

Effect Of Dicamba On Reproductive Development In Corn And Rice, Mason Castner, Jason K. Norsworthy, L. Tom Barber, Trenton Lee Roberts, Edward E. Gbur

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Research has been published regarding the effects of sublethal dicamba rates applied at different growth stages in soybean [Glycine max (L.) Merr.]; however, there is limited research on the effect of dicamba on reproductive growth in corn (Zea mays L.) and rice (Oryza sativa L.). Experiments were conducted in 2018 and 2019 to determine the potential consequences of dicamba exposure to reproductive stages of corn and rice. Dicamba was applied at 0.56, 5.6, 56, and 560 g ae ha^–1, with a 1X rate being 560 g ae ha^–1. Each rate was applied at …

Impacts Of Temperature And Carbon Dioxide On Boro Rice Production, Sabiha Ferdous

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

There are different anticipated impacts of climate change (CC) on agriculture all over the world. Bangladesh as a developing country has potential vulnerability and negative impacts on CC. This change in meteorological parameters creates negative impacts on agricultural production which is a threat to food security and economic development. The country has recently achieved food security in rice which is mainly due to increased yields and area coverage of irrigated dry season (Boro) rice over the last decades. It is necessary to predict the future Boro rice production in accordance with CC as well as take supplementary actions to ensure …

High Resistance To Quinclorac In Multiple-Resistant Echinochloa Colona Associated With Elevated Stress Tolerance Gene Expression And Enriched Xenobiotic Detoxification Pathway, Gulab Rangani, Christopher E. Rouse, Christopher Saski, Rooksana E. Noorai, Vijay Shankar, Amy L. Lawton-Rauh, Isabel S. Werle, Nilda Roma-Burgos

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Echinochloa colona and other species in this genus are a threat to global rice production and food security. Quinclorac, an auxin mimic, is a common herbicide for grass weed control in rice, and Echinochloa spp. have evolved resistance to it. The complete mode of quinclorac action and subsequent evolution of resistance is not fully understood. We analyzed the de novo transcriptome of multiple-herbicide-resistant (ECO-R) and herbicide-susceptible genotypes in response to quinclorac. Several biological processes were constitutively upregulated in ECO-R, including carbon metabolism, photosynthesis, and ureide metabolism, indicating improved metabolic efficiency. The transcriptional change in ECO-R following quinclorac treatment indicates an …

Measurable Microcystin In Ozark Streams Was Rare During Summer 2018 Baseflow Conditions, Bradley J. Austin, Brian E. Haggard

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Accelerated eutrophication due to human activity has been linked to an increase in the occurrence of cyanobacteria in freshwater systems. The purpose of this study was to document the occurrence of microcystin, a common cyanotoxin, within northwest Arkansas streams. Twenty streams were sampled from May through October 2018, and water and periphyton samples were analyzed for microcystin and chlorophyll-a (CHL-a). Mean microcystin concentrations in water samples were low across sites, ranging from < 0.10 to 0.21 μg L⁻¹. Mean microcystin in the periphyton across sites ranged from 2.6 to 9.9 μg m⁻² and were within values observed in the literature. …

Measurable Microcystin In Ozark Streams Was Rare During Summer 2018 Baseflow Conditions, Bradley J. Austin, Brian E. Haggard

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Accelerated eutrophication due to human activity has been linked to an increase in the occurrence of cyanobacteria in freshwater systems. The purpose of this study was to document the occurrence of microcystin, a common cyanotoxin, within northwest Arkansas streams. Twenty streams were sampled from May through October 2018, and water and periphyton samples were analyzed for microcystin and chlorophyll-a (CHL-a). Mean microcystin concentrations in water samples were low across sites, ranging from < 0.10 to 0.21 μg L⁻¹. Mean microcystin in the periphyton across sites ranged from 2.6 to 9.9 μg m⁻² and were within values observed in the literature. …

Soil Organic Carbon And Nutrients Affected By Tree Species And Poultry Litter In A 17-Year Agroforestry Site, Helen C.S. Amorim, Amanda J. Ashworth, Yuri L. Zinn, Thomas J. Sauer

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Tree species and fertilization sources may affect the soil organic carbon (SOC) and fertility in agroforestry (AF) systems in temperate regions, but this remains unexplored. This study assesses the longitudinal trends in the SOC and major nutrients in a 17-year AF site established on an Ultisol in Fayetteville, AR. We evaluated how management and fertilization (mineral vs. organic) affect the soil’s physical and chemical properties using the tree species: red oak (Quercus rubra L.) and pecan Carya illinoinensis (Wangenh.) K. Koch. Long-term applications of poultry litter increased the soil pH, whereas the Mg and S concentrations decreased compared to …

Estimation Of The Optimal Nitrogen Dose In A Brachiaria Humidicola-Corn Rotation System In The Colombian Eastern Plains, K. Enciso, S. Burkart

IGC Proceedings (1977-2023)

Improving nitrogen (N) use efficiency by optimizing the N fertilizer application dose is one way to reduce greenhouse gas (GHG) emissions in agriculture and livestock production, especially in higher demanding crops such as corn. Taking a Brachiaria humidicola (Bh)-corn rotation system in the Colombian Eastern Plains, we seek to determine both the optimal economic dose (OED) and the optimal technical dose (OTD) of N, which allow to maximize income at producer level and minimize environmental impacts. This particular rotation system was chosen as research subject given the presence of the residual effect of Biological Nitrogen Inhibition (BNI) in …

Screening And Breeding For Bermudagrass Stem Maggot (Bsm) Resistance Using U.S. Bermudagrass Germplasm, W. F. Anderson, D. Hancock, L. Baxter, W. Hudson, Esteban F. Rios

IGC Proceedings (1977-2023)

Bermudagrass (Cynodon sp.) is an important perennial forage grass grown in many parts of the world. Bermudagrass Stem Maggot (BSM) (Atherigona reversura Villeneuve) is an insect pest that reduces forage yield and nutritive value if it is not controlled. The pest, native to SE Asia, was first documented in North America in 2009 and is now considered invasive. A collection of over 300 forage bermudagrass accessions was evaluated in the field for susceptibility to BSM in 2014 and 2015. Tolerant lines and susceptible checks were then evaluated for yield loss due to BSM in a replicated field study …

What And Who Has Determined Adoption? A Study On Improved Forage Technologies In Colombia From An Agricultural Innovation System (Ais) Perspective, K. Enciso, N. Triana, M. Díaz, S. Burkart

IGC Proceedings (1977-2023)

The complex process behind the adoption of improved forages in Colombia remains largely unexplored. Despite governmental and scientific efforts to promote and disseminate the implementation of improved forages for the sake of sustainable livestock production, local livestock producers continue to extensively use native species and adoption rates of more efficient forages remain low. This study explores the dynamics behind the development and diffusion of improved forage technologies in Colombia, from the 1960's to the present through an Agricultural Innovation Systems (AIS) perspective. Here we map the agents involved, classify the roles they exerted over time and reconstruct the historical context …