Agricultural Science Commons^™

The Possibilities Of Explicit Striga (Striga Asiatica) Risk Monitoring Using Phenometric, Edaphic, And Climatic Variables, Demonstrated For Malawi And Zambia, Emily Kimathi, Bester Tawona Mudereri, Elfatih M. Abdel-Rahman, Saliou Niassy, Henri E.Z. Tonnang, Tobias Landmann

All Peer-Reviewed Publications

Food insecurity continues to affect more than two-thirds of the population in sub‐Saharan Africa (SSA), particularly those depending on rain-fed agriculture. Striga, a parasitic weed, has caused yield losses of cereal crops, immensely affecting smallholder farmers in SSA. Although earlier studies have established that Striga is a constraint to crop production, there is little information on the spatial extent of spread and infestation severity of the weed in some SSA countries like Malawi and Zambia. This study aimed to use remotely sensed vegetation phenological (n = 11), climatic (n = 3), and soil (n = 4) variables to develop a …

Enhancement Of Potato (Solanum Tuberosum L) Postharvest Quality By Use Of Magnetic Fields – A Case Of Shangi Potato Variety, Francis G. Irungu, Chrysantus M. Tanga, Francis G. Ndiritu, Simon G. Mathenge, Fredrick G. Kiruki, Symon M. Mahungu

All Peer-Reviewed Publications

Production of potatoes in the developing countries has been on the rise. This reinforces the growing importance of potatoes throughout Africa, Asia, and Latin America as a source of food and livelihood. However, this crop continues to experience major postharvest losses that are associated with a lack of effective storage facilities in these regions. This study used magnetic fields (MF) as an innovative technology to reduce potato losses while under storage. The effects of test variables; sources of magnetic fields intensity and exposure time on physicochemical properties of stored shangi potatoes were investigated. Double Helmholtz coils were used to generate …

Understanding The Potential Utility Of Tamarktm Grain Sorghum, Jacob Alan Fleming

Graduate Theses and Dissertations

Herbicide-resistant crops have been commonly used in corn, cotton, and soybean since the 1990s to control numerous different grass and broadleaf weeds. However, this technology has not been available for grain sorghum producers whom have faced challenges controlling grass weeds. Recently a collaboration between the University of Arkansas and Texas A&M University has resulted in a new bred line of grain sorghum, TamArkTM, which is resistant to ACCase inhibitor herbicides which have been previously used to control grass weeds in broadleaf crops. Multiple studies were conducted to determine the sensitivity of TamArkTM and problematic grass weeds to ACCase inhibitor herbicides, …

The Impact Of Policy Design On Willingness To Pay For Ecosystem Services From Prairie Strips, Karina A. Schoengold, Badri Khanal, Taro Mieno, Lisa Schulte Moore

Cornhusker Economics

Ecosystem services from farmland conservation are public good benefits. The value of these benefits is primarily measured using methods that determine the willingness to pay (WTP) for those benefits. Prairie strips, a farmland conservation practice, provide ecosystem services such as improved water quality, soil health, and biodiversity (Schulte et al., 2017). The state of Iowa is a major corn producer and contributes significant amounts of nitrogen and phosphorous to the Gulf of Mexico (Alexander et al., 2008). The development of conventional agricultural systems has also resulted in a significant loss of biodiversity, including a dominant land cover of tallgrass prairie. …

A Non-Destructive Approach For Measuring Rice Panicle-Level Photosynthetic Responses Using 3d-Image Reconstruction, Jaspinder Singh Dharni, Balpreet Kaur Dhatt, Puneet Paul, Tian Gao, Tala Awada, Harel Bacher4, Zvi Peleg, Paul E. Staswick, Jason Hupp, Hongfeng Yu, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Background: Our understanding of the physiological responses of rice inflorescence (panicle) to environmental stresses is limited by the challenge of accurately determining panicle photosynthetic parameters and their impact on grain yield. This is primarily due to the lack of a suitable gas exchange methodology for panicles and non-destructive methods to accurately determine panicle surface area.

Results: To address these challenges, we have developed a custom panicle gas exchange cylinder compatible with the LiCor 6800 Infra-red Gas Analyzer. Accurate surface area measurements were determined using 3D panicle imaging to normalize the panicle-level photosynthetic measurements. We observed differential responses in …

Bison Movements Change With Weather: Implications For Their Continued Conservation In The Anthropocene, Nicholas A. Mcmillan, Samuel D. Fuhlendorf, Barney Luttbeg, Laura E. Goodman, Craig A. Davis, Brady W. Allred, Robert G. Hamilton

Department of Agronomy and Horticulture: Faculty Publications

Animal movement patterns are affected by complex interactions between biotic and abiotic landscape conditions, and these patterns are being altered by weather variability associated with a changing climate. Some animals, like the American plains bison (Bison bison L.; hereafter, plains bison), are considered keystone species, thus their response to weather variability may alter ecosystem structure and biodiversity patterns. Many movement studies of plains bison and other ungulates have focused on point-pattern analyses (e.g., resource-selection) that have provided information about where these animals move, but information about when or why these animals move is limited. For example, information surrounding the …

The Genome Of Orychophragmus Violaceus Provides Genomic Insights Into The Evolution Of Brassicaceaepolyploidizationandits Distinct Traits, Kang Zhang, Yinqing Yang, Xin Zhang, Lingkui Zhang, Yu Fu, Zhongwei Guo, Shumin Chen, Jian Wu, James C. Schnable, Keke Yi, Xiaowu Wang, Feng Cheng

Department of Agronomy and Horticulture: Faculty Publications

Orychophragmus violaceus, referred to as ‘‘eryuelan’’ (February orchid) in China, is an early-flowering ornamental plant. The high oil content and abundance of unsaturated fatty acids in O. violaceus seeds make it a potential high-quality oilseed crop. Here, we generated a whole-genome assembly for O. violaceus using Nanopore and Hi-C sequencing technologies. The assembled genome of O. violaceus was ~1.3 Gb in size, with 12 pairs of chromosomes. Through investigation of ancestral genome evolution, we determined that the genome of O. violaceus experienced a tetraploidization event from a diploid progenitor with the translocated proto-Calepineae karyotype. Comparisons between the reconstructed subgenomes …

Novel Single-Nucleotide Variants For Morpho-Physiological Traits Involved In Enhancing Drought Stress Tolerance In Barley, Ibrahim S. Elbasyoni, Shamseldeen Eltaher, Sabah Morsy, Alsayed M. Mashaheet, Ahmed M. Abdallah, Heba G. Ali, Samah A. Mariey, P. Stephen Baenziger, Katherine Anna Frels

Department of Agronomy and Horticulture: Faculty Publications

Barley (Hordeum vulgare L.) thrives in the arid and semi-arid regions of the world; never-theless, it suffers large grain yield losses due to drought stress. A panel of 426 lines of barley was evaluated in Egypt under deficit (DI) and full irrigation (FI) during the 2019 and 2020 growing seasons. Observations were recorded on the number of days to flowering (NDF), total chlorophyll content (CH), canopy temperature (CAN), grain filling duration (GFD), plant height (PH), and grain yield (Yield) under DI and FI. The lines were genotyped using the 9K Infinium iSelect single nucleotide polymorphisms (SNP) genotyping platform, which …

Effects Of Sowing Date And Phosphorus Fertiliser Application On Winter Survival Of Lucerne Cv. Aohan In The Northern Semi-Arid Region Of China, Z. L. Wang, Q. Zh. Sun, Y. W. Wang, Zh. Y. Li, Sh. F. Zhao

IGC Proceedings (1977-2023)

In the northern semi-arid region of China, winter survival is always a limiting factor for lucerne production, because low temperatures and a dry climate in winter (Zhou et al., 1993; Ma, 2000; Sun & Gui, 2001; Sun et al., 2003). An experiment was conducted to find an appropriate sowing date and P application rate in order to improve lucerne winter survival.

Ear Emergence Of Different Grass Species Under Finnish Growing Conditions, M. Niskanen, O. Niemeläinen, L. Jauhiainen

IGC Proceedings (1977-2023)

Timothy is the most commonly cultivated grass species in Finland. Swards cultivated for silage of hay are of pure timothy or timothy is the dominant species of the mixture. Successful timing of harvesting of the primary growth is very critical in Northern latitudes where the stand develops very rapidly at daylengths of above 18 hours with a daily mean temperature close to 20 °C. The primary growth has to be harvested within a very short period to obtain a yield of high and uniform quality. Short harvesting periods require high capacity harvest machinery which lead to high costs. If it …

Reasons For The Premature Decline In Astragalus Adsurgens Stands In Kerqin Sandy Land, Q. Zh. Sun, Z. L. Wang, J. G. Han, Y. W. Wang, G. R. Liu

IGC Proceedings (1977-2023)

Diseases partly account for reductions in Astragalus adsurgens, stand longevity. The effect of some cultural practices on the control of pests and diseases have been reported (Hou, 1986; Nan, 1996), but few reports have detailed the relationship among soil fertiliser status, diseases and premature stand decline. This study was conducted to investigate these relationships in order to extend the longevity of Astragalus adsurgens stands.

The Influence Of Fertiliser Application To Strip-Sown Grasslands On Herbage Production And Quality, A. Kohoutek, P. Komárek, V. Odstrčilová, P. Nerušil

IGC Proceedings (1977-2023)

To increase the productivity of dairy cattle in the Czech Republic requires an improvement in herbage quality and an increase in the net energy of herbage. The decrease in cattle numbers by 50 % and the expansion of the grassland area both result in a surplus of feedstuffs of low quality. Introduction of strip-seeding of legumes and grasses into grasslands in interaction with fertilisation provides a possible solution to this problem.

Range-Based Livestock Production In Turkmenistan, R. H. Behnke, G. Davidson

IGC Proceedings (1977-2023)

Turkmenistan retains a centralized system of livestock production in which many critical assets are owned by the state. Though technically in the temperate zone, the country's climate is harsh and unstable. Groundwater resources are unevenly distributed, leaving many potential grazing areas seasonally inaccessible due to lack of drinking water for livestock. This paper summarizes the results of a three-year study of rangelands, livestock production, flock economics and land tenure at two study sites, one in central and the other in eastern Turkmenistan. The results of this study suggest that pastoral communities in Turkmenistan have coped remarkably well with the institutional …

Green Dairy, A Project For Environmental Friendly And Sustainable Dairy Systems In The Atlantic Area, H. Chambaut, A. Pflimlin, C. Raison

IGC Proceedings (1977-2023)

Green Dairy is an European Interreg III B project which runs over 3 years. It brings together 10 research and development partners from 5 countries and 11 regions of the Atlantic Area which range from Scotland to Portugal. It aims to provide a better understanding of the impact of intensive dairy systems on the quality of the environment in order to develop ways of improving practices in the different regions. This is expected to encourage more rapid responses to the problems of deteriorating water and air quality and a more appropriate response within or between regional contexts that could be …

Rangeland Ecological Management Counter-Measures Study Of Xinjiang, H. X. Cui, J. Li, S. Asiya, J. L. Zhang, Jialin

IGC Proceedings (1977-2023)

Xinjiang is located in the hinterland of the Asian-Euro continental area and far from the ocean. It is surrounded by mountains and forms a physiognomic landscape of two basins located in three mountains. This results in an extremely droughty continental climate and a harsh environment in the Temperate Zone. However, the geographical environment is diverse in the Xinjiang Autonomous region, the three high mountains and complicated geographical structure results in changes in ecological conditions with altitude and a diverse ecological environment. Because of the drought characteristics the desert area has developed different types of vegetation, and the complexity of the …

Management Options To Reduce N-Losses From Ploughed Grass-Clover, J. De Wit, G. J. Van Der Burgt, N. Van Eekeren

IGC Proceedings (1977-2023)

Nitrate (NO₃ -) leaching from grassland can be kept at acceptable levels, but is often high after ploughing for grassland renewal or for silage maize/grain production. In on-farm research with several organic farmers, management options are being explored to save scarce organic manure and to reduce N-losses.

Mechanical Aeration And Liquid Dairy Manure: Application Impacts On Grassland Runoff Water Quality And Yield, T. J. Basden, S. B. Shah, J. L. Miller

IGC Proceedings (1977-2023)

Wet weather on heavy soils reduces oxygen availability in the root zone and reduces forage yields. Mechanical aeration can improve forage yield in these soil conditions. Research has shown that under certain conditions, mechanical aeration can increase yield by improving drainage and aeration (Davies et al., 1989); aeration can also increase depression, storage and infiltration thus reducing surface runoff and improving nutrient distribution in the root zone. Aeration on sloping, fertilised grassland can provide environmental (Douglas et al., 1995) and agronomic benefits. The objectives of this study were to evaluate the runoff water quality and agronomic impacts of …

Nitrogen Dynamics Following The Break-Up Of Grassland On Three Different Sandy Soils, Manfred Kayser, K. Seidel, J. Müller

IGC Proceedings (1977-2023)

Nitrogen (N) is accumulated under grassland depending on factors such as soil type, management, and fertiliser input. Break-up of grassland stimulates mineralisation of organic N and may lead to increased soil mineral N and leaching losses (Lloyd, 1992). The objective of this study was to find out how site factors, e.g. soil, previous management and sward age, the following crop and the new level of N fertiliser affect the amount of inorganic N in autumn and the preceding mineralisation processes when grassland is ploughed in spring.

Fine Colloids ‘Carry’ Diffuse Water Contaminants From Grasslands, P. M. Haygarth, A. L. Heathwaite

IGC Proceedings (1977-2023)

The transport of diffuse pollutants from grassland has traditionally been described by the operationally defined threshold of greater, or smaller than a nominated membrane filter size. Most commonly this has been a 0.45 μm threshold to define ‘solute’ and ‘particulate’ transport. In this paper we shall use phosphorus (P) to help provide an example of the importance of colloid-facilitated transport.

Leaching Losses Of N, P And K From Grazed Legume Based Swards: Some Preliminary Results, E. R. Dixon, A. C. Stone, D. Scholefield, D. J. Hatch

IGC Proceedings (1977-2023)

There is increasing interest in sustainable agricultural systems because of environmental concerns. Animal production which utilises mixed grass and legume swards could be an effective measure in increasing the efficiency of nutrient utilisation, and investigation into different legume species is necessary. Leaching losses of N, P and K from 3 legume species under grazing by sheep were measured using Teflon-coated suction cups. The experiment took place on the UK site of the EU-funded, multi-site experiment – LEGGRAZE.

Soil Aggregate Dynamics, Particulate Organic Matter And Phosphate Under Dryland And Irrigated Pasture, J. T. Scott, L. M. Condron, R. W. Mcdowell

IGC Proceedings (1977-2023)

Soil aggregate formation and turnover affects the rate of occlusion or release of soil organic matter and therefore the availability for mineralisation or stabilisation of soil carbon (C) and phosphorus (P). Furthermore, differences in soil type, management and the quantity and quality of organic inputs can affect aggregate turnover rates (Six et al., 2000). Under pastoral farming the ratio of coarse particulate organic matter (inter-POM) inside macroaggregates but outside microaggregates to fine POM (intra-POM) within microaggregates may provide an indication of physical processes influencing mineralisation and stabilisation of soil C and organic P (Po). Our aim was to determine …

Fire And Nutrient Cycling In Shortgrass Steppe Of The Southern Great Plains, Usa, P. L. Ford, C. S. White

IGC Proceedings (1977-2023)

Fire in semi-arid grasslands releases nutrients bound up in organic matter and accelerates the rate of decomposition in the soil. This research experimentally tested effects of season and frequency of fire on nutrient cycling dynamics in shortgrass steppe. The objective was to identify if fire treatments have the ability to increase potential grassland productivity relative to untreated ‘reference condition’ grassland. Many such studies focus on short-term, direct effects of fire. However, this study is part of a long-term, 18-year study examining both direct, and indirect effects of fire in the growing vs. dormant season at return intervals of 3, 6 …

Maximising Slurry Crop Available Nitrogen Utilisation In Grassland Systems, J. R. Williams, E. Sagoo, B. J. Chambers, J. Laws, D. R. Chadwick

IGC Proceedings (1977-2023)

In the UK, approximately 90 million tonnes of animal manure containing ca 450,000 tonnes of nitrogen (N) are recycled to agricultural land each year. The efficient utilisation of manure N can save farmers money and reduce diffuse air (ammonia) and water (nitrate) pollution. For slurries, bandspreading techniques (e.g. trailing shoe and trailing hose) can improve N utilisation by reducing ammonia volatilisation losses compared with conventional broadcast applications. They also provide increased spreading opportunities in spring/summer as slurry is placed in a band on the soil surface limiting herbage contamination, which can reduce the need to apply slurry in the autumn/early …

Phosphorus Transfer To River Water From Grassland Catchments In Ireland, H. Tunney, P. Jordan, G. Kiely, R. Moles, G. Morgan, P. Byrne, W. Menary, K. Daly

IGC Proceedings (1977-2023)

In Ireland it is estimated that at least half of phosphorus (P) loss to water is from agricultural sources and National and European Union policy and legislation aim at reducing phosphorus (P) loss to water in order to reduce eutrophication. In Ireland, the average soil test P (STP) levels increased ten-fold, from less than 1 to over 8 mg Morgan P per l soil over the past 50 years, reflecting increased P inputs in fertiliser and animal feed. One of the main objectives of this three-year research programme, started in 2001, was to investigate P loss to water in grassland …

Denitrification Under Pastures On Permeable Soils Helps Protect Ground Water Quality, M. P. Russelle, B. A. Browne, N. B. Turyk, B. Pearson

IGC Proceedings (1977-2023)

Pastures have been implicated in ground water contamination by nitrate, especially in humid regions with thin or sandy soils (Stout et al., 2000). Significant losses can occur even under low N input, because available N from excreta patches often exceeds plant uptake capacity. Lack of evidence that appreciable nitrate leaching was occurring in established Midwestern USA pastures led us to test the hypothesis that denitrification was preventing or remediating nitrate loading. Higher denitrification rates have been found in the relatively limited number of trials since Ball & Ryden (1984) first reported the significance of this process in pastures.

Assessment Of Nitrogen Nutrition Status Of Grasses Under Water Deficit And Recovery, V. G. Dugo, Jean-Louis Durand, F. Gastal

IGC Proceedings (1977-2023)

Grasslands are rarely irrigated. They are therefore systematically submitted to more or less severe water deficits: as well as mineral deficiencies, water scarcity often also results in a reduction of nitrogen (N) status. Although identified some time ago, qualitatively, the interaction with N still remains difficult to take into account in quantitative analyses of crop physiology under water deficits. This paper illustrates how the nitrogen (N) status of the crop changes under water deficits. A N nutrition index (INN) was defined as the ratio of the actual N concentration of forage with the theoretical N concentration under optimal conditions, the …

Improving Nutrient Supply Of Grassland Soil, G. Füleky, M. Orbán

IGC Proceedings (1977-2023)

In the Southern corner of the Eastern Carpathian Mountains is located the hilly region of Barcaság. The total agricultural area is 180 thousand ha of which 90 thousand ha is grassland. The maximum yield of natural grassland does not exceed 1.2 t ha^-1 hay. The aim of this work is to find appropriate fertiliser and liming rates to increase the hay yield and improve the soil nutrient supply.

Safe - A Tool For Assessing The Sustainability Of Agricultural Systems: An Illustration, X. Sauvenier, C. Bielders, M. Hermy, E. Mathijs, B. Muys, J. Valckx, N. Van Cauwenbergh, M. Vanclooster, E. Wauters, A. Peeters

IGC Proceedings (1977-2023)

SAFE (Framework for Assessing Sustainability levels) is a tool for evaluating the sustainability of agricultural systems and uses a hierarchical framework populated with indicators objectively selected by multicriteria evaluation. Indicators are measured at field, farm and landscape scales and progressively integrated into a global sustainability index (SI). SAFE is illustrated below with results on a field scale from a farm site.

Genome‑Wide Association Analyses Of Leaf Rust Resistance In Cultivated Emmer Wheat, Dhondup Lhamo, Qun Sun, Qijun Zhang, Xuehui Li, Jason D. Fiedler, Guangmin Xia, Justin D. Faris, Yong‑Qiang Gu, Upinder Gill, Xiwen Cai, Maricelis Acevedo, Steven S. Xu

Department of Agronomy and Horticulture: Faculty Publications

Leaf rust, caused by Puccinia triticina (Pt), constantly threatens durum (Triticum turgidum ssp. durum) and bread wheat (Triticum aestivum) production worldwide. A Pt race BBBQD detected in California in 2009 poses a potential threat to durum production in North America because resistance source to this race is rare in durum germplasm. To find new resistance sources, we assessed a panel of 180 cultivated emmer wheat (Triticum turgidum ssp. dicoccum) accessions for seedling resistance to BBBQD and for adult resistance to a mixture of durum-specific races BBBQJ, CCMSS, and MCDSS in the field, and genotyped …

Nitrogen Response Of Spring And Winter Wheat To Biosolids Compared To Chemical Fertiliser, W. Kato, O. T. Carton, D. Mcgrath, H. Tunney, W. E. Murphy, P. O'Toole

IGC Proceedings (1977-2023)

Irish sewage sludge production was over 30,000 t/year in the 1990s (EPA, Ireland, 2003). Application to agricultural land is a management option for this organic material as it results in the recycling of the nutrients they contain for crop production. The EU Directive (91/271/EEC) encourages the recycling of sewage sludge as biosolids to agriculture. However, up to 1999, only about 5 % of biosolids produced was applied to agricultural land. In this study, several biosolids and a chemical fertiliser were used to assess N availability for spring and winter wheat (Triticum aestivum,) production in a pot experiment.