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Plant Sciences

South Dakota State University

Articles 61 - 77 of 77

Full-Text Articles in Physical Sciences and Mathematics

Interactive Effects Of Cover Crops, Invertebrate Communities And Soil Health In Corn Production Systems, Claire Lacanne Jan 2017

Interactive Effects Of Cover Crops, Invertebrate Communities And Soil Health In Corn Production Systems, Claire Lacanne

Electronic Theses and Dissertations

The adoption of regenerative farming practices is gaining traction, but the costs and benefits are not often considered on a systems level. Encouraging biodiversity and soil health is the goal of many agricultural practices used in regenerative farming; regenerative systems employ practices which abide by the two main principles of increasing biodiversity and decreasing disturbance, with the goal of encouraging ecosystem functioning to minimize inputs and maximize the productivity of a farm. I examined the management of corn (Zea mays) fields across four states in the Upper Midwest region of the United States. Regenerative systems in this study …

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Research Update: Bud Bank Ecology For Understanding Perennial Grass Persistence, Lan Xu May 2016

Research Update: Bud Bank Ecology For Understanding Perennial Grass Persistence, Lan Xu

Natural Resource Management Faculty Publications

Grassland ecosystems often demonstrate very remarkable resiliency to severe natural and anthropogenic disturbances. Such resiliency following disturbances comes from either seed banks (germinable seeds in the soil) or bud banks (meristems or buds, such as bulbs, bulbils, and buds on rhizomes, corms, and tubers, that generate vegetative tissues). Although seeds are important for dispersal, initial colonization, and maintenance of genetic diversity; few grass seeds persist in the soil more than five years, plus seed production often is unreliable under grazing. Recent studies have demonstrated that >99% of aboveground stems in undisturbed tallgrass prairie were recruited from the bud bank while <1% were recruited from the seed bank. Even under grazed or disturbed sites in tallgrass prairie, belowground buds make a significantly larger contribution (80%) to plant recruitment than do seeds (20%).

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Mapping Temperate Vegetation Climate Adaptation Variability Using Normalized Land Surface Phenology, Liang Liang, Mark D. Schwartz, Xiaoyang Zhang Apr 2016

Mapping Temperate Vegetation Climate Adaptation Variability Using Normalized Land Surface Phenology, Liang Liang, Mark D. Schwartz, Xiaoyang Zhang

GSCE Faculty Publications

Climate influences geographic differences of vegetation phenology through both contemporary and historical variability. The latter effect is embodied in vegetation heterogeneity underlain by spatially varied genotype and species compositions tied to climatic adaptation. Such long-term climatic effects are difficult to map and therefore often neglected in evaluating spatially explicit phenological responses to climate change. In this study we demonstrate a way to indirectly infer the portion of land surface phenology variation that is potentially contributed by underlying genotypic differences across space. The method undertaken normalized remotely sensed vegetation start-of-season (or greenup onset) with a cloned plants-based phenological model. As the …

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Great Plains Soils May Be C Sinks, David E. Clay, Gregg C. Carlson, Sharon A. Clay, James Stone, Kurtis Reitsma, Ronald Gelderman Jan 2012

Great Plains Soils May Be C Sinks, David E. Clay, Gregg C. Carlson, Sharon A. Clay, James Stone, Kurtis Reitsma, Ronald Gelderman

Agronomy, Horticulture and Plant Science Faculty Publications

Numerous studies with wide-ranging results have been conducted to resolve if Great Plains soils are a C source or sink. The authors addressed the source/sink question by examining the results from producer soil samples and production surveys that were analyzed and archived by the South Dakota Soil Testing Laboratory. Results showed that between 1985 and 2010, soil organic C content increased at a rate of 326 lb C/A/year, for a total increase of 24%. The increase was attributed to planting better adapted varieties and using better management practices that on average increased corn grain yields 2.29 bu/A/year. Higher soil organic …

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Soil Organic Carbon Maintenance Requirements And Mineralizatyion Rate Constants: Site Specific Calculations, David Clay, Gregg Carlson, Sharon Clay Oct 2011

Soil Organic Carbon Maintenance Requirements And Mineralizatyion Rate Constants: Site Specific Calculations, David Clay, Gregg Carlson, Sharon Clay

Agronomy, Horticulture and Plant Science Faculty Publications

Over the past 100 years numerous studies have been conducted with the goal of quantifying the impact of management on carbon turnover. It is difficult to conduct a mechanistic evaluation of these studies because each study was conducted under unique soil, climatic, and management conditions. Techniques for directly comparing data from unique studies are needed. This paper: 1) demonstrates an approach for calculating SOC maintenance requirements and mineralization rate constants at different landscape positions; and 2) discusses techniques for conducting site- specific experiments and determining site-specific C sequestration potentials.

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South Dakota Thriving, Fall 2009, College Of Agriculture &. Biological Sciences Oct 2009

South Dakota Thriving, Fall 2009, College Of Agriculture &. Biological Sciences

Growing South Dakota (Publication of the College of Agriculture, Food and Environmental Sciences)

Table of Contents:
[Page] 2 Growing Farmers Markets: South Dakota Cooperative Extension Service Helps Develop and Grow Booming Homegrown markets
[Page] 4 Lighari Leads Restructuring of Extension: Director of South Dakota Cooperative Extension Service Focuses on Building Relationships
[Page} 6 South Dakota's Newest Research Station: The Addition of the SDSU Cow Camp Means Another Tremendous Resource for South Dakota and SDSU
[Page] 8 SDSU Rodeo Builds World Champs: Focus on Academics and Team Leads to Success Inside Both the Classroom and the Arena
|[Page] 12 Behind the Scenes in SDSU's Anatomy Lab: SDSU's Hands-On Anatomy Lab Gives Students the Edge …

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What Limits Fire? An Examination Of Driver's Of Burnt Area In Southern Africa, Sally Archibald, David P. Roy, Brian W. Van Wilgen, Robert J. Scholes Jan 2008

What Limits Fire? An Examination Of Driver's Of Burnt Area In Southern Africa, Sally Archibald, David P. Roy, Brian W. Van Wilgen, Robert J. Scholes

GSCE Faculty Publications

The factors controlling the extent of fire in Africa south of the equator were investigated using moderate resolution (500 m) satellite-derived burned area maps and spatial data on the environmental factors thought to affect burnt area. A random forest regression tree procedure was used to determine the relative importance of each factor in explaining the burned area fraction and to address hypotheses concerned with human and climatic influences on the drivers of burnt area. The model explained 68% of the variance in burnt area. Tree cover, rainfall in the previous 2 years, and rainfall seasonality were the most important predictors. …

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Sorption-Desorption Of Imidacloprid And Its Metabolites In Soil And Vadose Zone Materials, Sharon V. Papiernik, William C. Koskinen, Lucia Cox, Pamela J. Rice, Sharon A. Clay, Nancy R. Werdin-Pfisterer, Kristen A. Norberg Jan 2006

Sorption-Desorption Of Imidacloprid And Its Metabolites In Soil And Vadose Zone Materials, Sharon V. Papiernik, William C. Koskinen, Lucia Cox, Pamela J. Rice, Sharon A. Clay, Nancy R. Werdin-Pfisterer, Kristen A. Norberg

Agronomy, Horticulture and Plant Science Faculty Publications

Sorption-desorption is one of the most important processes affecting the leaching of pesticides through soil because it controls the amount of pesticide available for transport. Subsurface soil properties can significantly affect pesticide transport and the potential for groundwater contamination. This research characterized the sorption-desorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-Nnitro-2-imidazolidinimine) and three of its metabolites, 1-[(6-chloro-3-pyridinyl)methyl]-2-imidazolidinone (imidacloprid-urea), 1-[(6-chloro-3-pyridinyl)methyl]-4,5-dihydro-1H-imidazol-2-amine (imidaclopridguanidine), and 1-[(6-chloro-3-pyridinyl)methyl]-1H-imidazol-2-amine (imidacloprid-guanidine-olefin), as a function of changing soil properties with depth in two profiles extending from the surface to a depth of 1.8 or 8 m. Sorption of each compound was highly variable and hysteretic in all cases. Normalizing the sorption coefficients (Kf) …

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Theoretical Derivation Of Stable And Nonisotopic Approaches For Assessing Soil Organic Carbon Turnover, D. E. Clay, C. G. Carlson, S. A. Clay, C. Reese, Z. Liu, J. Chang, M. M. Ellsbury Jan 2006

Theoretical Derivation Of Stable And Nonisotopic Approaches For Assessing Soil Organic Carbon Turnover, D. E. Clay, C. G. Carlson, S. A. Clay, C. Reese, Z. Liu, J. Chang, M. M. Ellsbury

Agronomy, Horticulture and Plant Science Faculty Publications

Techniques for measuring soil organic C (SOC) turnover in production fields are needed. The objectives of this study were to propose and test nonisotopic and 13 C stable isotopic techniques for assessing SOC turnover. Based on SOC equilibrium and mass balance relationships, an equation was derived: NHC/SOC initial=[1/(SOC× k NHC)](dSOC/dt)+ k SOC/k NHC, where dSOC/dt is the annual change in SOC, NHC is nonharvested C returned to soil, k SOC is the annual mineralization rate of SOC, and k NHC is the annual mineralization rate of NHC. This equation was used to calculate maintenance rates. An isotopic approach based on …

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Factors Influencing Spatial Variability Of Soil Apparent Electrical Conductivity, D. E. Clay, J. Chang, D. D. Malo, C. G. Carlson, C. Reese, S. A. Clay, M. Ellsbury, B. Berg Jan 2001

Factors Influencing Spatial Variability Of Soil Apparent Electrical Conductivity, D. E. Clay, J. Chang, D. D. Malo, C. G. Carlson, C. Reese, S. A. Clay, M. Ellsbury, B. Berg

Agronomy, Horticulture and Plant Science Faculty Publications

Soil apparent electrical conductivity (ECa) can be used as a precision farming diagnostic tool more efficiently if the factors influencing ECa spatial variability are understood. The objective of this study was to ascertain the causes of ECa spatial variability in soils developed in an environment with between 50 and 65 cm of annual rainfall. Soils at the research sites were formed on calcareous glacial till parent materials deposited approximately 10,000 years ago. Soil samples (0–15 cm) collected from at least a 60 by 60 m grid in four fields were analyzed for Olsen phosphorus (P) and …

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Measures Of Denitrification In Selected South Dakota Semi-Permanent Prairie Pothole Wetlands, Beverly S. Klein Jan 2001

Measures Of Denitrification In Selected South Dakota Semi-Permanent Prairie Pothole Wetlands, Beverly S. Klein

Electronic Theses and Dissertations

Wetlands are an integral part of agricultural systems in the prairie pothole regions of the North Central United States and Canadian Provinces. Little research has been done on denitrification in prairie potholes, and a better understanding of their denitrifying capability could aide in optimizing management practices near pothole areas. Most probable number (MPN) and denitrifying enzyme activity (DEA or Phase I) assays were conducted. Most probable number (MPN) measures were used to give an estimate of dissimilatory nitrate reduction to ammonia (DNRA) and denitrifying populations present in the wetlands. This study involved 3 selected semi-permanent prairie pothole wetlands near Madison, …

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Herbicide Movement And Dissipation At Four Midwestern Sites, S. A. Clay, R. H. Dowdy, J. A. Lamb, J. L. Anderson, B. Lowery, R. E. Knight, D. E. Clay May 2000

Herbicide Movement And Dissipation At Four Midwestern Sites, S. A. Clay, R. H. Dowdy, J. A. Lamb, J. L. Anderson, B. Lowery, R. E. Knight, D. E. Clay

Agronomy, Horticulture and Plant Science Faculty Publications

This study was conducted to evaluate atrazine (2‐chloro‐4‐ethylamino‐6‐isopropyl‐1, 3, 5‐triazine) and alachlor (2‐chIoro‐N‐(methoxymethyl)acetamide) dissipation and movement to shallow aquifers across the Northern Sand Plains region of the United States. Sites were located at Minnesota on a Zimmerman fine sand, North Dakota on Hecla sandy loam, South Dakota on a Brandt silty clay loam, and Wisconsin on a Sparta sand. Herbicide concentrations were determined in soil samples taken to 90 cm four times during the growing season and water samples taken from the top one m of aquifer at least once every three months. Herbicides were detected to a …

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Precision Farming Protocols. Part 2. Comparison Of Sampling Approaches For Precision Phosphorus Management, David E. Clay, Jiyul Chang, C. Gregg Carlson, Doug Malo, Sharon A. Clay, Mike Ellsbury Jan 2000

Precision Farming Protocols. Part 2. Comparison Of Sampling Approaches For Precision Phosphorus Management, David E. Clay, Jiyul Chang, C. Gregg Carlson, Doug Malo, Sharon A. Clay, Mike Ellsbury

Agronomy, Horticulture and Plant Science Faculty Publications

Research is needed to compare the different techniques for developing site‐specific phosphorus (P) recommendations on a field‐wide basis. The objective of this study was to determine the impact different techniques for developing site‐specific P recommendation maps on yield and profitability. Enterprise analysis combined with a crop simulation model and detailed field characterization was used to estimate the value of spatial P information in a system where N was not limiting. The systems evaluated were continuous corn (Zea mays) and corn and soybean (Gfycine max) rotations where sampling and fertilizer applications were applied annually and semi‐annually, respectively. The sampling techniques tested …

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Field Scale Variability Of Nitrogen And Δ15n In Soil And Plants, D. E. Clay, J. Chang, S. A. Clay, M. Ellsbury, C. G. Carlson, D. D. Malo, D. Woodson, T. Desttur Nov 1998

Field Scale Variability Of Nitrogen And Δ15n In Soil And Plants, D. E. Clay, J. Chang, S. A. Clay, M. Ellsbury, C. G. Carlson, D. D. Malo, D. Woodson, T. Desttur

Agronomy, Horticulture and Plant Science Faculty Publications

Understanding the factors that influence soil and plant nitrogen (N) spatial variability may improve our ability to develop management systems that maximize productivity and minimize environmental hazards. The objective of this study was to determine the field (65 ha) scale spatial variability of N and δ15N in soil and corn (Zea mays). Soil, grain, and stover samples were collected from grids that ranged in size from 30 by 30 m to 60 by 60 m. Plant samples, collected following physiological maturity in 1995, were analyzed for total N and δ15N. Soil samples, collected prior …

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Factors Affecting Atrazine Fate In North Central U.S. Soils, W. C. Koskinen, Sharon Clay Jan 1997

Factors Affecting Atrazine Fate In North Central U.S. Soils, W. C. Koskinen, Sharon Clay

Agronomy, Horticulture and Plant Science Faculty Publications

Atrazine (6-chloro-N-ethyl-N′-(l-methylethyl)-l,3,5-triazine-2,4-diamine) is a herbicide of the triazine family used for controlling broadleaf and some grassy weeds in corn and sorghum. Since its introduction in the late 1950s, atrazine has been a popular herbicide because it is relatively inexpensive and, in most cases, gives good season-long weed control. It can be applied pre-or postemergence and is often tank mixed with grass herbicides, such as alachlor (2-chloro-N-(2,6-diethylphenyl-N-(methoxymethyl)acetamide), metolachlor(2-chloro-N-(2-2ethyl-6-methylphenyl)-N-(2-methoxy-l-methylethyl) acetamide), butylate (S-ethyl bis(2-methylpropyl)carbamothioate), or EPTC (S-ethyl dipropylcarbamothioate), or with other broadleaf herbicides, such as dicamba (3,6-dichloro-2-methoxybenzoic …

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Historical Crop / Climate Relationships In South Dakota, D.G. Kenefick, J.C. Harlan, K.K. Weischedel, P.D. Evenson Jan 1984

Historical Crop / Climate Relationships In South Dakota, D.G. Kenefick, J.C. Harlan, K.K. Weischedel, P.D. Evenson

Agronomy, Horticulture, and Plant Science Publications

Crop performance and climatic records were collated for high production counties in South Dakota to evaluate the effects of temperature and precipitation on yields. The crops involved were corn, soybeans, sorghum, oats, spring wheat, and winter wheat. Records were compared for the period from 1965 to 1982. The computer data file for each county includes seven climatic parameters, dates of plant development, adjusted yield-and yield rank by year. The crop/climate record for the 17-year period was evaluated in sixteen counties per crop each year. Thus, 272 county x year observations were made for each crop, except for soybeans which involved …

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The Effect Of Cultivation On Certain Chemical And Physical Properties Of Some South Dakota Soils, Oscar E. Olson Jan 1937

The Effect Of Cultivation On Certain Chemical And Physical Properties Of Some South Dakota Soils, Oscar E. Olson

Electronic Theses and Dissertations

Soil Nutrient losses have followed closely in the paths of advancing frontiers in agriculture. Remedies for depletion as the result of overcropping were sought by George Washington, whose interest and investigation of soil nutrient losses probably represent the earliest attention given to land exploitation in the United States, which at the present time has become a problem of national concern. Soil losses have been attributed to a number of causes , among which are cropping, erosion, leaching, burning, and rapid oxidation of organic matter in the soil. Associated with soil nutrient losses, certain significant physical and chemical changes may occur …

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