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Gone With The Wind: Soil Moisture Effects On Gaseous Nitrogen Removal From Wastewater, Faith L. Anderson May 2016

Gone With The Wind: Soil Moisture Effects On Gaseous Nitrogen Removal From Wastewater, Faith L. Anderson

Senior Honors Projects

Onsite wastewater treatment systems (OWTS), or septic systems, release nitrogen (N), which can be detrimental to aquatic ecosystems. The final step in the treatment of wastewater is dispersal onto a drainfield, where it percolates through the soil. Part of the N is removed from wastewater and released into the atmosphere as N2 and N2O by denitrification, which requires anoxic conditions. Previous studies looking at the effect of soil water-filled pore space (WFPS) on denitrification using clean water with a high level of dissolved O2 (DO) have identified a minimum of 60% WFPS for denitrification to take …


Evaluating Pedestrial Compaction Variation & Soil Organic C Content, Gunner B. Decker Apr 2016

Evaluating Pedestrial Compaction Variation & Soil Organic C Content, Gunner B. Decker

Scholars Week

Over time, playing fields are monitored by overall appearance. However, pedestrian compaction is not evenly distributed throughout the entire surface.


Soil Microbial Community Composition And Respiration Along An Experimental Precipitation Gradient In A Semiarid Steppe, Cancan Zhao, Yuan Miao, Chengde Yu, Lili Zhu, Feng Wang, Lin Jiang, Dafeng Hui, Shiqiang Wan Apr 2016

Soil Microbial Community Composition And Respiration Along An Experimental Precipitation Gradient In A Semiarid Steppe, Cancan Zhao, Yuan Miao, Chengde Yu, Lili Zhu, Feng Wang, Lin Jiang, Dafeng Hui, Shiqiang Wan

Biology Faculty Research

As a primary limiting factor in arid and semiarid regions, precipitation strongly influences soil microbial properties. However, the patterns and mechanisms of soil microbial responses to precipitation have not been well documented. In this study, changes in soil microorganisms along an experimental precipitation gradient with seven levels of precipitation manipulation (i.e., ambient precipitation as a control and ±20%, ±40% and ±60% of ambient precipitation) were explored in a semiarid temperate steppe in northern China. Soil microbial biomass carbon and respiration as well as the ratio of fungal to bacterial biomass varied along the experimental precipitation gradient and peaked under the …


Extent Of Capillary Rise In Sands And Silts, Rachel Lynn Salim Apr 2016

Extent Of Capillary Rise In Sands And Silts, Rachel Lynn Salim

Masters Theses

The values reported in literature for the height of capillary rise in fine sands, silts, and clays are contradictory. Most of the values were based on mathematical models, which used estimated rather than measured input data. This work measured capillary rise values in laboratory experiments in fine-grained sands and silts.

Two uniform sands with grains 0.35--0.7 mm in diameter and 0.3-0.6 mm in diameter, silt with an average grain size below 40 microns, and 0.35--0.7 mm sand coated with a water-repellant spray were carefully packed into two-inch diameter glass columns. These columns were placed into clear plastic tanks with water …


Pengaruh Penambahan Arang Sekam Dan Jumlah Cabang Produksi Terhadap Pertumbuhan Tanaman, Hasil Dan Kualitas Buah Tomat Kultivar Doufu Hasil Sambung Batang Pada Inceptisol Jatinangor, Nasrulloh, Tino Mutiarawati, Wawan Sutari Mar 2016

Pengaruh Penambahan Arang Sekam Dan Jumlah Cabang Produksi Terhadap Pertumbuhan Tanaman, Hasil Dan Kualitas Buah Tomat Kultivar Doufu Hasil Sambung Batang Pada Inceptisol Jatinangor, Nasrulloh, Tino Mutiarawati, Wawan Sutari

Jurnal Kultivasi

Tomat beef merupakan salah satu jenis tomat yang mempunyai nilai ekonomis tinggi. Salah satu teknik budidaya yang dapat diguna-kan untuk meningkatkan produksi tanaman tomat yaitu perbaikan media tanam dengan penambahan arang sekam dan mengatur jumlah cabang produksi. Percobaan bertujuan untuk mempelajari berbagai dosis arang sekam dan jumlah cabang produksi yang baik untuk pertumbuhan, hasil dan kualitas tomat. Penelitian dilaksanakan di Laboratorium Kultur Terkendali, Fakultas Pertanian, Univer-sitas Padjadjaran di Jatinangor. Rancangan percobaan menggunakan Rancangan Petak Terbagi dengan tiga ulangan. Petak utama adalah penambahan arang sekam dengan empat taraf: 0%, 10%, 20%, 30% dan anak petak adalah jumlah cabang produksi dengan dua …


Nanoparticles Composed Of Zn And Zno Inhibit Peronospora Tabacina Spore Germination In Vitro And P. Tabacina Infectivity On Tobacco Leaves, George Wagner, Victor Korenkov, Jonathan D. Judy, Paul M. Bertsch Mar 2016

Nanoparticles Composed Of Zn And Zno Inhibit Peronospora Tabacina Spore Germination In Vitro And P. Tabacina Infectivity On Tobacco Leaves, George Wagner, Victor Korenkov, Jonathan D. Judy, Paul M. Bertsch

Plant and Soil Sciences Faculty Publications

Manufactured nanoparticles (NPs) are increasingly being used for commercial purposes and certain NP types have been shown to have broad spectrum antibacterial activity. In contrast, their activities against fungi and fungi-like oomycetes are less studied. Here, we examined the potential of two types of commercially available Zn NPs (Zn NPs and ZnO NPs) to inhibit spore germination and infectivity on tobacco leaves resulting from exposure to the fungi-like oomycete pathogen Peronospora tabacina (P. tabacina). Both types of NPs, as well as ZnCl2 and bulk ZnO control treatments, inhibited spore germination compared to a blank control. ZnO ENMs …


Developing Probability Maps For Locating And Scouting Unprotected Areas Of Gravel Hill Prairies On Rodman Soils Along The Wabash River Valley Near Lafayette, Indiana, Ryan W.R. Schroeder Mar 2016

Developing Probability Maps For Locating And Scouting Unprotected Areas Of Gravel Hill Prairies On Rodman Soils Along The Wabash River Valley Near Lafayette, Indiana, Ryan W.R. Schroeder

Engagement & Service-Learning Summit

No abstract provided.


Designing A Suite Of Measurements To Understand The Critical Zone, Susan L. Brantley, Roman A. Dibiase, Tess A. Russo, Yuning Shi, Henry Lin, Kenneth J. Davis, Margot Kaye, Lillian Hill, Jason Kaye, David M. Eissenstat, Beth Hoagland, Ashlee L.D. Dere, Andrew L. Neal, Kristen M. Brubaker, Dan K. Arthur Mar 2016

Designing A Suite Of Measurements To Understand The Critical Zone, Susan L. Brantley, Roman A. Dibiase, Tess A. Russo, Yuning Shi, Henry Lin, Kenneth J. Davis, Margot Kaye, Lillian Hill, Jason Kaye, David M. Eissenstat, Beth Hoagland, Ashlee L.D. Dere, Andrew L. Neal, Kristen M. Brubaker, Dan K. Arthur

Geography and Geology Faculty Publications

Many scientists have begun to refer to the earth surface environment from the upper canopy to the depths of bedrock as the critical zone (CZ). Identification of the CZ as an integral object worthy of study implicitly posits that the study of the whole earth surface will provide benefits that do not arise when studying the individual parts. To study the CZ, however, requires prioritizing among the measurements that can be made – and we do not generally agree on the priorities. Currently, the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO) is expanding from a small original focus area (0.08 …


The Secret Ingredients Of Clover: Biochanin A And Isoflavonoids, Michael Flythe, Glen Aiken, Isabelle Kagan Jan 2016

The Secret Ingredients Of Clover: Biochanin A And Isoflavonoids, Michael Flythe, Glen Aiken, Isabelle Kagan

Kentucky Grazing Conference

It is well known that the value of clover is in nitrogen. Clovers fix their own nitrogen so that an input of nitrate fertilizer is not required. Furthermore, they are rich in protein-nitrogen, and can be used to meet the protein requirements of ruminants. Clovers also contain a class of chemicals called isoflavones, and we have recently discovered evidence that the isoflavones positively influence the way that ruminants digest protein.


Experimental Evidence For Drought Induced Alternative Stable States Of Soil Moisture, David A. Robinson, Scott B. Jones, Inma Lebron, Sabine Reinsch, Maria T. Dominguez, Andrew R. Smith, Davey L. Jones, Miles R. Marshall, Bridget A. Emmett Jan 2016

Experimental Evidence For Drought Induced Alternative Stable States Of Soil Moisture, David A. Robinson, Scott B. Jones, Inma Lebron, Sabine Reinsch, Maria T. Dominguez, Andrew R. Smith, Davey L. Jones, Miles R. Marshall, Bridget A. Emmett

Plants, Soils, and Climate Faculty Publications

Ecosystems may exhibit alternative stable states (ASS) in response to environmental change. Modelling and observational data broadly support the theory of ASS, however evidence from manipulation experiments supporting this theory is limited. Here, we provide long-term manipulation and observation data supporting the existence of drought induced alternative stable soil moisture states (irreversible soil wetting) in upland Atlantic heath, dominated by Calluna vulgaris (L.) Hull. Manipulated repeated moderate summer drought, and intense natural summer drought both lowered resilience resulting in shifts in soil moisture dynamics. The repeated moderate summer drought decreased winter soil moisture retention by ∼10%. However, intense summer drought, …


Discordant Data And Interpretation Of Results From Wildlife Habitat Models, Anita T. Morzillo, Michael G. Wing, Justin Long Jan 2016

Discordant Data And Interpretation Of Results From Wildlife Habitat Models, Anita T. Morzillo, Michael G. Wing, Justin Long

Journal of Geospatial Applications in Natural Resources

Wildlife habitat management is an important part of natural resource management. As a result, there are a large number of models and tools for wildlife habitat assessment. A consequence of the many assessment tools is inconsistency when comparing results between tools, which may lead to potential confusion management decisions. Our objective was to compare results from two wildlife habitat models – one being relatively coarse (HUC5) scale and not spatially dynamic and the other being finer scale spatial data based on a 30 m spatial resolution –for habitat assessment of three species across the West Cascades of Oregon: Northern spotted …


Experimental Genome-Wide Determination Of Rna Polyadenylation In Chlamydomonas Reinhardtii, Stephen A. Bell, Chi Shen, Alishea Brown, Arthur G. Hunt Jan 2016

Experimental Genome-Wide Determination Of Rna Polyadenylation In Chlamydomonas Reinhardtii, Stephen A. Bell, Chi Shen, Alishea Brown, Arthur G. Hunt

Plant and Soil Sciences Faculty Publications

The polyadenylation of RNA is a near-universal feature of RNA metabolism in eukaryotes. This process has been studied in the model alga Chlamydomonas reinhardtii using low-throughput (gene-by-gene) and high-throughput (transcriptome sequencing) approaches that recovered poly(A)-containing sequence tags which revealed interesting features of this critical process in Chlamydomonas. In this study, RNA polyadenylation has been studied using the so-called Poly(A) Tag Sequencing (PAT-Seq) approach. Specifically, PAT-Seq was used to study poly(A) site choice in cultures grown in four different media types—Tris-Phosphate (TP), Tris-Phosphate-Acetate (TAP), High-Salt (HS), and High-Salt-Acetate (HAS). The results indicate that: 1. As reported before, the motif UGUAA is …


Evaluating The Impact Of Natural And Agricultural Ecosystems On Soil Properties In Western Kentucky., Cody Masterson Jan 2016

Evaluating The Impact Of Natural And Agricultural Ecosystems On Soil Properties In Western Kentucky., Cody Masterson

Murray State Theses and Dissertations

The importance and capabilities of soil are often overlooked. It has an exceedingly complex ecosystem that is still not fully understood, but looking into soil properties can provide a clearer picture of what goes on below the surface. Understanding the influence of land covers and soil management allow for better understanding of how the soil ecosystem works which in return provides insight into how to create a more sustainable form of agriculture. Different ecosystems greatly impact soil properties. Soil physical properties are considered sensitive indicators of perturbation due to soil management practices and land covers. The four ecosystems that were …


Composting Swine Manure From High Rise Finishing Facilities, Edwin L. Ritchey, Kim Cook Jan 2016

Composting Swine Manure From High Rise Finishing Facilities, Edwin L. Ritchey, Kim Cook

Plant and Soil Sciences Research Report

Swine production has restructured considerably in recent years with increased production on fewer farms (Key et al., 2011). Most swine production facilities manage manure in liquid form either in deep pits underneath production facilities or in lagoons adjacent to the production facilities (Key et al., 2011). This management uses water to rinse manure from the facilities, which dilutes the nutrient concentration and value of the manure. The liquid forms are applied to land through irrigation systems or by liquid manure spreaders. Liquid manure management can have some operational constraints that composting eliminates (Bernal et al., 2009). The most common issue …


Soil Cores For Kentucky Science Education, Mark S. Coyne, Carol Hanley, Amber Harris Jan 2016

Soil Cores For Kentucky Science Education, Mark S. Coyne, Carol Hanley, Amber Harris

Plant and Soil Sciences Faculty Book Gallery

No abstract provided.


Soil Properties Affect Establishment Of Invasive Species, Celastrus Orbiculatus, In A Lower Hudson River Riparian Ecosystem, Shabana Hoosein Hoosein Jan 2016

Soil Properties Affect Establishment Of Invasive Species, Celastrus Orbiculatus, In A Lower Hudson River Riparian Ecosystem, Shabana Hoosein Hoosein

Legacy Theses & Dissertations (2009 - 2024)

The Hudson River Estuary has been colonized by numerous terrestrial invasive plant species, due in part to its history of anthropogenic and natural disturbance riparian dynamics. This study investigates the spatial patterns of a widespread invasion by Oriental (or Asiatic) bittersweet (Celastrus orbiculatus Thunb.) in Schodack Island State Park, Rensselaer and Columbia Counties. The Park is home to rare species and communities, several of which are threatened by the encroachment of bittersweet. Bittersweet populations were mapped and surveyed on a fixed grid throughout the island, to determine distribution patterns. Stem densities were approximately 50% higher in sites with dredged material …


Soil Organic Matter Distribution In A Douglas-Fir-Tanoak Forest, Humboldt County, California, Hollie A. Ernest Jan 2016

Soil Organic Matter Distribution In A Douglas-Fir-Tanoak Forest, Humboldt County, California, Hollie A. Ernest

Cal Poly Humboldt theses and projects

Soil carbon (C) affects the active gases in the atmosphere, nutrient cycling, and diversity of flora and fauna. Soil organic matter (SOM) is partially comprised of C, and a widely-accepted ratio of 0.58 organic carbon (OC) to organic matter (OM) is used to measure soil C on a landscape scale. However, this ratio varies according to vegetation, depth, hydrology, and may lead to miscalculations of soil C and SOM estimates. Soil C and SOM are inherently complex and it is not completely understood which environmental factors have the most influence in their formation, which occurs on a time scale of …


Effects Of Chemical Amendments To Swine Manure On Runoff Quality, Elizabeth L. Bullock, Dwayne R. Edwards, Phillip A. Moore Jr., Richard S. Gates Jan 2016

Effects Of Chemical Amendments To Swine Manure On Runoff Quality, Elizabeth L. Bullock, Dwayne R. Edwards, Phillip A. Moore Jr., Richard S. Gates

Biosystems and Agricultural Engineering Faculty Publications

Land-applied swine manure can be an environmental concern when runoff losses of manure constituents occur. The use of chemical amendments to mitigate these losses has been investigated for poultry litter, but materials such as swine manure have received less attention in this context, particularly at the plot scale or larger. The objective of this experiment was to evaluate the impacts of aluminum sulfate (alum; Al2(SO4)3), aluminum chloride (AlCl3), and ferric chloride (FeCl3) addition on runoff of selected constituents of land-applied swine manure. Manure was collected from feeder pigs fed a …


Effects Of Epichloë Coenophiala−Tall Fescue Symbiosis On Plant-Microbe-Soil Interactions In A Temperate Pasture, Lindsey C. Slaughter Jan 2016

Effects Of Epichloë Coenophiala−Tall Fescue Symbiosis On Plant-Microbe-Soil Interactions In A Temperate Pasture, Lindsey C. Slaughter

Theses and Dissertations--Plant and Soil Sciences

Plants interact in myriad ways with microorganisms to influence ecosystem processes such as nutrient cycling, which can regulate ecosystem response to global change. One important plant-microbe symbiosis occurs between cool-season grasses and asexual fungal Epichloë endophytes, such as tall fescue (Schedonorus arundinaceus) and Epichloë coenophiala. Because the common toxic strain of the endophyte (CTE) harms grazing livestock, non-livestock toxic endophyte (NTE) strains have been developed and are increasingly deployed in pastures. Little is known about how these symbioses impact other plant-microbe interactions and microbe-mediated soil processes in grassland ecosystems. I conducted three studies to determine how E. …


Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk Jan 2016

Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk

Dartmouth Scholarship

Forests are more frequently being managed to store and sequester carbon for the purposes of climate change mitigation. Generally, this practice involves long-term conservation of intact mature forests and/or reductions in the frequency and intensity of timber harvests. However, incorporating the influence of forest surface albedo often suggests that long rotation lengths may not always be optimal in mitigating climate change in forests characterized by frequent snowfall. To address this, we investigated trade-offs between three ecosystem services: carbon storage, albedo-related radiative forcing, and timber provisioning. We calculated optimal rotation length at 498 diverse Forest Inventory and Analysis forest sites in …


Spanish River Carbonatite: Its Benefits And Potential Use As A Soil Supplement In Agriculture, James J Jan 2016

Spanish River Carbonatite: Its Benefits And Potential Use As A Soil Supplement In Agriculture, James J

Theses and Dissertations (Comprehensive)

A critical problem facing agriculture today is being able to consistently and sustainably provide plants with adequate nutrients for growth. With this problem being exacerbated by the ever-increasing human population, new perspectives and techniques are required to ensure global food security. In order to fully realize potential solutions, however, plant growth and nutrition cannot be exclusively focused upon. The soil-microorganism-plant system is comprised of many interconnected and interdependent processes that together support plant growth: it is upon these processes that the focus must be placed. In this work, the agromineral Spanish River Carbonatite (SRC) is characterized using the framework of …


Evaluating The Biogeochemical Functioning Of A Constructed Fen On The Post-Mining Landscape Of Athabasca Oil Sands Region, Fort Mcmurray, Alberta, Canada, Felix C. Nwaishi Jan 2016

Evaluating The Biogeochemical Functioning Of A Constructed Fen On The Post-Mining Landscape Of Athabasca Oil Sands Region, Fort Mcmurray, Alberta, Canada, Felix C. Nwaishi

Theses and Dissertations (Comprehensive)

Peatlands have a unique biogeochemical function, characterized by an imbalance between the rates of biomass accumulation and decomposition. These characteristics facilitate the ability of peatlands to support the sequestration of nutrients and carbon. In disturbed peatlands, these functions are compromised. Thus, reclamation targets amongst other key functions, the recovery of biogeochemical functioning. These functions could serve as a measure of recovery to conditions that are present in natural analogues. This thesis examines the recovery of microbially-mediated nutrient transformation processes in a fen peatland that was constructed on a post-mining landscape in the Athabasca oil sands region, Fort McMurray, Alberta. The …


The Role Of Amino Acids In The Nitrogen Cycle Of Peatlands, Tia Scarpelli Jan 2016

The Role Of Amino Acids In The Nitrogen Cycle Of Peatlands, Tia Scarpelli

Dissertations, Master's Theses and Master's Reports

Future release of carbon from peatlands in response to climate change may be impacted by nitrogen limitation. The current study considers the role of amino acids as a nitrogen source in peatlands. The total free amino acid (TFAA) concentration for peats ranged from 0-2.3 µM, and leucine was the primary contributor. The dominance of sedge or ericaceous shrub plant types did not significantly impact the TFAA pool. Ammonium concentrations were much greater than TFAA and nitrate concentrations. TFAA concentrations were greatest in spring and least in fall. The springtime maxima and summer decrease in concentrations were simulated in a modeling …


A Desert In Disguise: The Resilience Of The Nebraska Sandhills, Jeff Hartman Dec 2015

A Desert In Disguise: The Resilience Of The Nebraska Sandhills, Jeff Hartman

School of Natural Resources: Dissertations, Theses, and Student Research

The Nebraska Sandhills are the largest sand dune system in the Western Hemisphere, and are unique because they remain relatively undisturbed from row crop agriculture. Research in the past two decades demonstrated that the Sandhills are dynamic on millennial timescales, switching between stabilized, vegetated states to non-vegetated, mobilized states. The Sandhills are currently stabilized, but understanding how ecological processes are altered as sand dunes transition from stabilized to mobilized states, provides insight into the thresholds, stability, and resilience of this grassland ecosystem. My research investigated the impacts of vegetation disturbances on ecological processes and the sand dune surface stability. For …


The Effect Of Warming And Simulated Rainfall On Soil Microbial Community Structure And Function, Torri A. Ivancic Dec 2015

The Effect Of Warming And Simulated Rainfall On Soil Microbial Community Structure And Function, Torri A. Ivancic

Biology Theses

Soil respiration, from plant roots and soil microbes, accounts for 60 – 80 percent of total ecosystem respiration, with the microbial component contributing approximately 54 percent. Global climate trends resulting from CO2 emissions include increased soil temperatures and changes in precipitation regimes resulting in less frequent, more intense rainfall events. Soil temperature and moisture availability drive soil respiration rates, but how they impact the microbial respiration is poorly qualified. I investigated how the soil microbial community responds to changes in temperature and moisture availability in a laboratory based experiment. Soils from a mixed hardwood forest under two thermal regimes …


Available Nitrogen And Denitrification In Soil Altered By Ground Cover And Nutrient Source In An Organic Apple Orchard, Jade Nicole Ford Dec 2015

Available Nitrogen And Denitrification In Soil Altered By Ground Cover And Nutrient Source In An Organic Apple Orchard, Jade Nicole Ford

Graduate Theses and Dissertations

A shift in public demand towards more organic and locally produced fruit and vegetables has been occurring across the United States in recent years. A common practice in organic fruit production is the application of organic ground covers to supply nutrients while enhancing other soil properties. A need for research exists in the southern region of the U.S. examining the effects of regionally applicable ground cover and nutrient management on nitrogen availability and the microbial community to provide information to organic farmers in the region. Two studies were conducted to determine how 12 treatment combinations of four ground covers (compost, …


Defining The Potassium Nutritional Requirements And Distribution Among Plant Parts Of Representative Soybean Cultivars From Different Maturity Groups, Md. Rasel Parvej Dec 2015

Defining The Potassium Nutritional Requirements And Distribution Among Plant Parts Of Representative Soybean Cultivars From Different Maturity Groups, Md. Rasel Parvej

Graduate Theses and Dissertations

The potassium (K) requirement of soybean [Glycine max (L.) Merr.] was investigated to determine whether cultivar sensitivity to K deficiency was affected by growth habit (determinate or indeterminate) and how cultivars from each growth habit accumulate and distribute K among plant structures. We also diagnosed K deficiency across reproductive growth stages (R2-6) using trifoliolate leaf- and petiole-K concentrations and at harvest (R8) using seed-K concentration. Soybean responded similarly to K deficiency in terms of yield, selected yield components, and seed-K concentration, regardless of growth habit. The yield loss from K deficiency was greatest on the middle to upper nodes of …


Validation Of Soil-Test-Based Phosphorus And Potassium Fertilizer Recommendations For Rice And Soybean, Matthew Scott Fryer Dec 2015

Validation Of Soil-Test-Based Phosphorus And Potassium Fertilizer Recommendations For Rice And Soybean, Matthew Scott Fryer

Graduate Theses and Dissertations

The science of soil-testing for nutrient management and fertilizer recommendations is widely accepted among scientists and agronomists. Although this science is unsurpassed in predicting soil nutrient availability, soil-test interpretations are seldom validated. Major research objectives for irrigated soybean [Glycine max (L.) Merr.] and direct-seeded, delayed-flood rice (Oryza sativa L.) were to: i) validate the accuracy of Mehlich-3 soil-test P (STP) and K (STK) interpretations and ii) published critical tissue-P and -K interpretations in predicting the yield response to fertilizer at different significance levels (p≤0.05 to 0.25), iii) examine how seed nutrient concentrations are influenced by fertilization and crop response to …


Mercury In Coniferous And Deciduous Upland Forests In Northern New England, Usa: Implications Of Climate Change, J. B. Richardson, A. J. Friedland Nov 2015

Mercury In Coniferous And Deciduous Upland Forests In Northern New England, Usa: Implications Of Climate Change, J. B. Richardson, A. J. Friedland

Dartmouth Scholarship

Climatic changes in the northeastern US are expected to cause coniferous stands to transition to deciduous stands over the next hundred years. Mercury (Hg) sequestration in forest soils may change as a result. In order to understand potential effects of such a transition, we studied aboveground vegetation and soils at paired coniferous and deciduous stands on eight mountains in Vermont and New Hampshire, USA.


Management Options For Water-Repellent Soils In Australian Dryland Agriculture, M. M. Roper, S. L. Davies, P. S. Blackwell, D. J. M. Hall, D. Bakker, R. Jongepier, P. R. Ward Oct 2015

Management Options For Water-Repellent Soils In Australian Dryland Agriculture, M. M. Roper, S. L. Davies, P. S. Blackwell, D. J. M. Hall, D. Bakker, R. Jongepier, P. R. Ward

Natural Resources Research Articles

Water-repellent (‘non-wetting’) soils are a major constraint to agricultural production in southern and south-west Australia, affecting >10 Mha of arable sandy soils. The major symptom is dry patches of surface soil, even after substantial rainfall, directly affecting agricultural production through uneven crop and pasture germination, and reduced nutrient availability. In addition, staggered weed germination impedes effective weed control, and delayed crop and pasture germination increases the risk of wind erosion. Water repellency is caused by waxy organic compounds derived from the breakdown of organic matter mostly of plant origin. It is more prevalent in soils with a sandy surface texture; …