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Full-Text Articles in Life Sciences

Miscanthus Sacchariflorus – Biofuel Parent Or New Weed?, Catherine L. Bonin, Emily A. Heaton, Jessica Barb Nov 2014

Miscanthus Sacchariflorus – Biofuel Parent Or New Weed?, Catherine L. Bonin, Emily A. Heaton, Jessica Barb

Agronomy Publications

The perennial grass triploid Miscanthus × giganteus is a promising renewable bioenergy feedstock in the United States and Europe. Originating from eastern Asia, this species is a sterile hybrid cross between M. sinensis and M. sacchariflorus. While research has begun to examine the impacts of M. sinensis and triploid M. × giganteus on the landscape, M. sacchariflorus has been largely overlooked in the peer-reviewed literature. This review article discusses the origin, uses, distribution, and invasive potential of M. sacchariflorus. M. sacchariflorus is capable of producing high yields (10.7 t DM ha−1 yr−1), generally does not reproduce by seed, and ...


Forest Succession, Soil Carbon Accumulation, And Rapid Nitrogen Storage In Poorly-Remineralized Soil Organic Matter, David Bruce Lewis, Michael J. Castellano, Jason P. Kaye Oct 2014

Forest Succession, Soil Carbon Accumulation, And Rapid Nitrogen Storage In Poorly-Remineralized Soil Organic Matter, David Bruce Lewis, Michael J. Castellano, Jason P. Kaye

Agronomy Publications

Substantial nitrogen (N) retention by temperate terrestrial ecosystems results from the rapid storage of newly deposited N in stable soil organic matter. Yet, we poorly understand the ecosystem properties that regulate the kinetics of this process. We applied mineral 15N to temperate hardwood forest soils to test the hypothesis that N stabilization is faster owing to greater stocks of soil carbon (C) in late-successional than in young forests. Within 26 minutes of addition, about 30% of tracer N was stored in stable form in organic-horizon soil with a median residence time of >29 years. About 5–10% of tracer ...


Switchgrass Response To Nitrogen Fertilizer Across Diverse Environments In The Usa: A Regional Feedstock Partnership Report, C. O. Hong, V. N. Owens, D. Bransby, R. Farris, J. Fike, E. Heaton, S. Kim, H. Mayton, R. Mitchell, D. Viands Sep 2014

Switchgrass Response To Nitrogen Fertilizer Across Diverse Environments In The Usa: A Regional Feedstock Partnership Report, C. O. Hong, V. N. Owens, D. Bransby, R. Farris, J. Fike, E. Heaton, S. Kim, H. Mayton, R. Mitchell, D. Viands

Agronomy Publications

The Regional Feedstock Partnership is a collaborative effort between the Sun Grant Initiative (through Land Grant Universities), the US Department of Energy, and the US Department of Agriculture. One segment of this partnership is the field-scale evaluation of switchgrass (Panicum virgatum L.) in diverse sites across the USA. Switchgrass was planted (11.2 kg PLS ha−1 ) in replicated plots in New York, Oklahoma, South Dakota, and Virginia in 2008 and in Iowa in 2009. Adapted switchgrass cultivars were selected for each location and baseline soil samples collected before planting. Nitrogen fertilizer (0, 56, and 112 kg N ha−1 ...


Particulate And Active Soil Nitrogen Fractions Are Reduced By Sheep Grazing In Dryland Cropping Systems, Upendra M. Sainju, Joy L. Barsotti, Andrew W. Lenssen, Patrick G. Hatfield Jul 2014

Particulate And Active Soil Nitrogen Fractions Are Reduced By Sheep Grazing In Dryland Cropping Systems, Upendra M. Sainju, Joy L. Barsotti, Andrew W. Lenssen, Patrick G. Hatfield

Agronomy Publications

Sheep (Ovis aries L.) grazing, a cost-effective method of weed control compared to herbicide application and tillage, may influence N cycling by consuming crop residue and weeds and returning N through feces and urine to the soil. The objective of this experiment was to evaluate the effect of sheep grazing compared to tillage and herbicide application for weed control on soil particulate and active soil N fractions in dryland cropping systems. Our hypothesis was that sheep grazing used for weed control would increase particulate and active soil N fractions compared to tillage and herbicide application. Soil samples collected at the ...


Land Use And Hydrologic Flowpaths Interact To Affect Dissolved Organic Matter And Nitrate Dynamics, Ehsan R. Toosi, John P. Schmidt, Michael J. Castellano Apr 2014

Land Use And Hydrologic Flowpaths Interact To Affect Dissolved Organic Matter And Nitrate Dynamics, Ehsan R. Toosi, John P. Schmidt, Michael J. Castellano

Agronomy Publications

The transport and transformation of dissolved organic matter (DOM) and dissolved inorganic nitrogen (DIN) through the soil profile impact down-gradient ecosystems and are increasingly recognized as important factors affecting the balance between accumulation and mineralization of subsoil organic matter. Using zero tension and tension lysimeters at three soil depths (20, 40, 60 cm) in paired forest and maize/soybean land uses, we compared dissolved organic C (DOC), dissolved organic N (DON) and DIN concentrations as well as DOM properties including hydrophilic-C (HPI-C), UV absorption (SUVA254), humification index and C/N ratio. Soil moisture data collected at lysimeter locations suggest ...


Accuracy And Precision Of No Instrument Is Guaranteed, Javed` Iqbal, Michael J. Castellano, Timothy B. Parkin Mar 2014

Accuracy And Precision Of No Instrument Is Guaranteed, Javed` Iqbal, Michael J. Castellano, Timothy B. Parkin

Agronomy Publications

Photoacoustic infrared spectroscopy (PAS) is increasingly used for measurement of N2O and CO2 fluxes at the soil surface. However, PAS calibration is complex. Water vapor, CO2, and temperature interfere with accurate N2O measurement. To accurately measure N2O, PAS calibrations must compensate for these interferences. Our article, ‘Evaluation of photoacoustic infrared spectroscopy for the simultaneous measurement of N2O and CO2 gas concentrations and fluxes at the soil surface’ (Iqbal et al., 2013), compared PAS and gas chromatography (GC) analytical procedures. Results demonstrated that PAS can measure N2O concentrations ...


Nitrogen Use In Durum And Selected Brassicaceae Oilseeds In Two-Year Rotations, B. L. Allen, Andrew W. Lenssen, Upendra M. Sainju, Thecan Caesar-Tonthat, R. G. Evans Feb 2014

Nitrogen Use In Durum And Selected Brassicaceae Oilseeds In Two-Year Rotations, B. L. Allen, Andrew W. Lenssen, Upendra M. Sainju, Thecan Caesar-Tonthat, R. G. Evans

Agronomy Publications

Brassicaceae oilseeds can serve as potential feedstocks for renewable biofuels to offset demand for petroleum-based alternatives. However, little is known about oilseed crop yield potential and N use in semiarid, wheat (Triticum spp.)-based cropping systems that dominate the northern Great Plains (NGP). A 5-yr study was conducted in northeast Montana to investigate the yield potential of a direct seeded system of durum (T. durumDesf.) in rotation with either chemical fallow or three Brassicaceae oilseeds: camelina [Camelina sativa (L.) Crantz], crambe (Crambe abyssinica Hochst. ex R.E. Fries), and canola-quality Brassica juncea L. Overall, results from the study indicated ...


Soil Temperature Is Positively Associated With Dissolved Organic Carbon Supply And Negatively Associated With Soil Solution Nitrate, Ehsan R. Toosi, John P. Schmidt, Michael J. Castellano Feb 2014

Soil Temperature Is Positively Associated With Dissolved Organic Carbon Supply And Negatively Associated With Soil Solution Nitrate, Ehsan R. Toosi, John P. Schmidt, Michael J. Castellano

Agronomy Publications

The role of abiotic processes on dissolved organic matter (DOM) production is often underappreciated. However, abiotic processes appear to be especially important in subsoils where, with increasing depth, microbial activity declines and soil organic matter (SOM) becomes a progressively more important contributor to DOM. Within three soil depths (20, 40, and 60 cm) in a temperate forest, soil temperature was positively associated with dissolved organic carbon (DOC) concentration (R2 = 0.23–0.77) and the DOM humification index (R2 = 0.35–0.72) for soil solutions in slow and fast flowpaths. With increasing soil temperature from 5 to ...


A Long-Term N Fertilizer Gradient Has Little Effect On Soil Organic Matter In A High-Intensity Maize Production System., Kimberly H. Brown, Elizabeth M. Bach, Rhae A. Drijber, Kirsten S. Hofmockel, Elizabeth S. Jeske, John E. Sawyer, Michael J. Castellano Feb 2014

A Long-Term N Fertilizer Gradient Has Little Effect On Soil Organic Matter In A High-Intensity Maize Production System., Kimberly H. Brown, Elizabeth M. Bach, Rhae A. Drijber, Kirsten S. Hofmockel, Elizabeth S. Jeske, John E. Sawyer, Michael J. Castellano

Agronomy Publications

Global maize production alters an enormous soil organic C (SOC) stock, ultimately affecting greenhouse gas concentrations and the capacity of agroecosystems to buffer climate variability. Inorganic N fertilizer is perhaps the most important factor affecting SOC within maize-based systems due to its effects on crop residue production and SOC mineralization. Using a continuous maize cropping system with a 13 year N fertilizer gradient (0–269 kg N ha−1 yr−1) that created a large range in crop residue inputs (3.60–9.94 Mg dry matter ha−1 yr−1), we provide the first agronomic assessment of long-term N ...


An Investigation To Enhance Understanding Of The Stimulation Of Weed Seedling Emergence By Soil Disturbance, B. J. Schulte, B. J. Tomasek, A. S. Davis, L. Andersson, D. L. Benoit, A. Cirujeda, Jack Dekker, Frank Forcella, J. L. Gonzalez-Andujar, F. Graziani, A. J. Murdoch, P. Neve, I. A. Rasmussen, B. Sera, J. Salonen, F. Tei, K. S. Terresen, J. M. Urbano Feb 2014

An Investigation To Enhance Understanding Of The Stimulation Of Weed Seedling Emergence By Soil Disturbance, B. J. Schulte, B. J. Tomasek, A. S. Davis, L. Andersson, D. L. Benoit, A. Cirujeda, Jack Dekker, Frank Forcella, J. L. Gonzalez-Andujar, F. Graziani, A. J. Murdoch, P. Neve, I. A. Rasmussen, B. Sera, J. Salonen, F. Tei, K. S. Terresen, J. M. Urbano

Agronomy Publications

Enhanced understanding of soil disturbance effects on weed seedling recruitment will help guide improved management approaches. Field experiments were conducted at 16 site-years at 10 research farms across Europe and North America to (i) quantify superficial soil disturbance (SSD) effects on Chenopodium album emergence and (ii) clarify adaptive emergence behaviour in frequently disturbed environments. Each site-year contained factorial combinations of two seed populations (local and common, with the common population studied at all site-years) and six SSD timings [0, 50, 100, 150, 200 day-degrees (d°C, base temperature 3°C) after first emergence from undisturbed soil]. Analytical units in this ...


Sensible Heat Balance Measurements Of Soil Water Evaporation Beneath A Maize Canopy, X. Xiao, J. L. Heitman, T. J. Sauer, T. Ren, Robert Horton Jan 2014

Sensible Heat Balance Measurements Of Soil Water Evaporation Beneath A Maize Canopy, X. Xiao, J. L. Heitman, T. J. Sauer, T. Ren, Robert Horton

Agronomy Publications

Soil water evaporation is an important component of the water budget in cropped fields; few methods are available for continuous and independent measurement. A sensible heat balance (SHB) approach has been demonstrated for continuously determining soil water evaporation under bare surface conditions. Applicability of SHB measurements beneath a crop canopy cover has not been evaluated. We tested SHB using heat-pulse sensors to estimate evaporation beneath a full maize (Zea mays L.) canopy. We also implemented a modified SHB approach incorporating below-canopy net radiation, which extended the range of conditions under which SHB is applicable. Evaporation was measured at three positions ...


Midwest Vision For Sustainable Fuel Production, Kenneth J. Moore, Stuart J. Birrell, Robert C. Brown, Michael D. Caster, Jill E. Euken, H. Mark Hanna, Dermot J. Hayes, Jason D. Hill, Keri L. Jacobs, Catherine L. Kling, David A. Laird, Robert B. Mitchell, Patrick T. Murphy, D. Raj Raman, Charles V. Schwab, Kevin J. Shinners, Kenneth P. Vogel, Jeffrey J. Volenic Jan 2014

Midwest Vision For Sustainable Fuel Production, Kenneth J. Moore, Stuart J. Birrell, Robert C. Brown, Michael D. Caster, Jill E. Euken, H. Mark Hanna, Dermot J. Hayes, Jason D. Hill, Keri L. Jacobs, Catherine L. Kling, David A. Laird, Robert B. Mitchell, Patrick T. Murphy, D. Raj Raman, Charles V. Schwab, Kevin J. Shinners, Kenneth P. Vogel, Jeffrey J. Volenic

Agronomy Publications

This article charts the progress of CenUSA Bioenergy, a USDA-NIFA-AFRI coordinated agricultural project focused on the North Central region of the US. CenUSA’s vision is to develop a regional system for producing fuels and other products from perennial grass crops grown on marginally productive land or land that is otherwise unsuitable for annual cropping. This article focuses on contributions CenUSA has made to nine primary systems needed to make this vision a reality: feedstock improvement; feedstock production on marginal land; feedstock logistics; modeling system performance; feedstock conversion into biofuels and other products; marketing; health and safety; education, and outreach ...


Novel Germplasm And Screening Methods For Early Cold Tolerance In Sorghum, Maria G. Salas-Fernandez, Gregory R. Schoenbaum, A. Susana Goggi Jan 2014

Novel Germplasm And Screening Methods For Early Cold Tolerance In Sorghum, Maria G. Salas-Fernandez, Gregory R. Schoenbaum, A. Susana Goggi

Agronomy Publications

Sorghum [Sorghum bicolor (L.) Moench] is well known for its great potential to produce grain, feed, and fuel under stressful conditions such as drought and heat. However, its genetic potential to withstand cold, wet environments at germination has not been extensively exploited due to limited sources of early season cold tolerance. The objective of this study was to select novel, not previously characterized, cold-tolerant sorghum accessions that can germinate in a traditional cold test at 10°C in the laboratory and emerge in the field under a wide range of stressful conditions. Fifty six accessions (38 Kaoliangs and 18 non-Kaoliang ...


Long-Term Fate Of Nitrate Fertilizer In Agricultural Soils Is Not Necessarily Related To Nitrate Leaching From Agricultural Soils, Michael J. Castellano, Mark B. David Jan 2014

Long-Term Fate Of Nitrate Fertilizer In Agricultural Soils Is Not Necessarily Related To Nitrate Leaching From Agricultural Soils, Michael J. Castellano, Mark B. David

Agronomy Publications

Accounting for the fate of inorganic N fertilizer in agricultural systems is critical to sustainable production. Sebilo et al. (1) provide a unique long-term record of 15NO3 fertilizer fate that demonstrates N molecules from a discrete fertilizer application are transferred to soil organic matter (SOM) and subsequently mineralized over the course of ca.100 years during which they contribute to NO3 leaching. The authors conclude “attempts to reduce agricultural nitrate contamination of aquatic systems must consider the long-term legacy of past applications of synthetic fertilizers”. Further, they suggest a recent decrease in anthropogenic N inputs to the Mississippi River Basin ...


Agriculture, Jerry Hatfield, Eugene Takle, Richard Grotjahn, Patrick Holden, R. César Izaurralde, Terry Mader, Elizabeth Marshall, Diana Liverman Jan 2014

Agriculture, Jerry Hatfield, Eugene Takle, Richard Grotjahn, Patrick Holden, R. César Izaurralde, Terry Mader, Elizabeth Marshall, Diana Liverman

Agronomy Publications

No abstract provided.


Field Test And Sensitivity Analysis Of A Sensible Heat Balance Method To Determine Soil Ice Contents, Yuki Kojima, Joshua L. Heitman, Gerald N. Glerchinger, Tusheng Ren, Robert P. Ewing, Robert Horton Jan 2014

Field Test And Sensitivity Analysis Of A Sensible Heat Balance Method To Determine Soil Ice Contents, Yuki Kojima, Joshua L. Heitman, Gerald N. Glerchinger, Tusheng Ren, Robert P. Ewing, Robert Horton

Agronomy Publications

Feasibility of the sensible heat balance (SHB) method for determining in situ soil ice content with heat pulse (HP) sensors was evaluated using field measurements. The required accuracy of HP sensor measurements for SHB was further assessed with a sensitivity analysis. Improving accuracy of thermal conductivity measurements and using short time steps are necessary to accurately estimate ice contents with the SHB method.

Soil ice content impacts winter vadose zone hydrology. It may be possible to estimate changes in soil ice content with a sensible heat balance (SHB) method, using measurements from heat pulse (HP) sensors. Feasibility of the SHB ...


Spatial And Temporal Dynamics Of Soil-Surface Carbon Dioxide Emissions In Bioenergy Corn Rotations And Reconstructed Prairies, Aaron L. Daigh, Thomas J. Sauer, Xinhua Xiao, Robert Horton Jan 2014

Spatial And Temporal Dynamics Of Soil-Surface Carbon Dioxide Emissions In Bioenergy Corn Rotations And Reconstructed Prairies, Aaron L. Daigh, Thomas J. Sauer, Xinhua Xiao, Robert Horton

Agronomy Publications

The interest in bioenergy crops has raised questions as to the potential of management strategies to preserve soil C pools and soil quality. Since soil-surface CO2 effluxes are a major fate of soil C, knowledge of CO2 efflux’s spatial and temporal trends among bioenergy crops will facilitate advances in research on improving terrestrial C-cycle models as well as decision support tools for policy and land-management. Our objective was to evaluate spatial and temporal dynamics of soil-surface CO2 effluxes in bioenergy-based corn (Zea mays L.) and reconstructed prairie systems. Systems evaluated included continuous corn (harvested for grain ...


Time Domain Reflectometry Waveform Analysis With Second-Order Bounded Mean Oscillation, Zhuangji Wang, Yuki Kojima, Songtao Lu, Yan Chen, Robert Horton, Robert C. Schwartz Jan 2014

Time Domain Reflectometry Waveform Analysis With Second-Order Bounded Mean Oscillation, Zhuangji Wang, Yuki Kojima, Songtao Lu, Yan Chen, Robert Horton, Robert C. Schwartz

Agronomy Publications

Tangent-line methods and adaptive waveform interpretation with Gaussian filtering (AWIGF) have been proposed for determining reflection positions of time domain reflectometry (TDR) waveforms. However, the accuracy of those methods is limited for short-probe TDR sensors. Second-order bounded mean oscillation (BMO) may be an alternative method to determine reflection positions of short-probe TDR waveforms. For this study, an algorithm of second-order BMO is developed. Example waveforms are analyzed with tangent-line methods, AWIGF method, and second-order BMO to illustrate the difference among the three methods. For some waveforms, second-order BMO appears be able to give more plausible results. Automatic implementation was challenging ...


Measurement Of Soil Water Content With Dielectric Dispersion Frequency, Jinghui Xu, Sally D. Logsdon, Xiaoyi Ma, Robert Horton, Wenting Han, Ying Zhao Jan 2014

Measurement Of Soil Water Content With Dielectric Dispersion Frequency, Jinghui Xu, Sally D. Logsdon, Xiaoyi Ma, Robert Horton, Wenting Han, Ying Zhao

Agronomy Publications

Frequency domain reflectometry (FDR) is an inexpensive and attractive methodology for repeated measurements of soil water content (θ). Although there are some known measurement limitations for dry soil and sand, a fixed-frequency method is commonly used with commercially available FDR probes. The purpose of our study was to determine if the soil dielectric spectrum could be used to measure changes in θ. A multifrequency FDR probe was constructed with a 6-mm diameter, and a soil dielectric spectrum was obtained. Using the dielectric spectrum, the dielectric dispersion frequency (fd) was determined. It was discovered that changes in fd were ...


Validation Of Two Models For Self‐Incompatibility In Autotetraploid Perennial Ryegrass Using High Resolution Melting‐Based Markers, Andrea Arias Aguirre, Bruno Studer, Javier Do Canto, Ursula Frei, Thomas Lubberstedt Jan 2014

Validation Of Two Models For Self‐Incompatibility In Autotetraploid Perennial Ryegrass Using High Resolution Melting‐Based Markers, Andrea Arias Aguirre, Bruno Studer, Javier Do Canto, Ursula Frei, Thomas Lubberstedt

Agronomy Publications

Lolium perenne (ryegrass) is a species of major economic importance due to its multiple uses such as forage, turf, and cover crop and its potential use as a feedstock for bioenergy. Ryegrass occurs naturally as a diploid (2n=14). However, several autotretraploid cultivars were obtained via colchicination. Ryegrass displays a two-locus gametophytic self-incompatibility system (SI) that remains intact even at the tetraploid level. There are two plausible models for SI at the tetraploid level, Model I in which only one different allele in the pollen grain from the female at either S or Z locus makes pollen compatible. Model II ...