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Full-Text Articles in Life Sciences

Soil And Land- Use Change Sustainability In The Northern Great Plains Of The Usa, Deepak Raj Joshi, David E. Clay, Alexander Smart, Sharon A. Clay, Tulsi P. Kharel, Umakanta Mishra Mar 2019

Soil And Land- Use Change Sustainability In The Northern Great Plains Of The Usa, Deepak Raj Joshi, David E. Clay, Alexander Smart, Sharon A. Clay, Tulsi P. Kharel, Umakanta Mishra

Agronomy, Horticulture and Plant Science Faculty Publications

In the Northern Great Plains (NGP), the combined impacts of land-use and climate variability have the potential to place many soils on the tipping point of sustainability. The objectives of this study were to assess if the conversion of grassland to croplands occurred on fragile landscapes in the North America Northern Great Plains. South Dakota and Nebraska were selected for this study because they are located in a climate transition zone. We visually classified 43,200 and 38,400 points in South Dakota and Nebraska, respectively, from high-resolution imagery in 2006, 2012, and 2014 into five different categories (cropland, grassland, habitat, NonAg, …


Mob Grazing Results In High Forage Utilization And Reduced Western Snowberry Size, Heidi Reed, Sharon Clay, Alexander Smart, David Clay, Michelle Ohrtman Jan 2019

Mob Grazing Results In High Forage Utilization And Reduced Western Snowberry Size, Heidi Reed, Sharon Clay, Alexander Smart, David Clay, Michelle Ohrtman

Agronomy, Horticulture and Plant Science Faculty Publications

Mob-grazing strives to maximize forage utilization and minimize selective grazing by using high stocking densities in small paddocks for short durations (12–24 hr). Rotational-grazing uses low stocking densities for a longer time period, retaining about half of the original available forage; although selective grazing can occur. Three cattle (Bos taurus × Bos indicus) grazing intensities: mob- (stocking densities from 32,000 to 67,000 kg ha−1; duration—24 hr); rotation (stocking density—2500 kg ha−1; duration—35 d); and non-grazed systems were compared based on forage utilization and changes to western snowberry (Symphoricarpos occidentalis) (WS) patch volume in a 2-year South Dakota study. …


Mob Vs. Rotational Grazing: Impact On Forage Use And Artemisia Absinthium, Heidi Reed, Alexander Smart, David E. Clay, Michelle Ohrtman, Sharon A. Clay Jan 2018

Mob Vs. Rotational Grazing: Impact On Forage Use And Artemisia Absinthium, Heidi Reed, Alexander Smart, David E. Clay, Michelle Ohrtman, Sharon A. Clay

Agronomy, Horticulture and Plant Science Faculty Publications

Short duration (≤24 h), high stocking density grazing systems (e.g., mob grazing) mimics historic prairie grazing patterns of American bison (Bison bison), and should minimize selective grazing. We compared mob [125 cow-calf pairs on either 0.65 ha for 12 h; or 1.3 ha for 24 h] vs. rotational [25 cow-calf pairs on 8.1 ha for 20 days starting in mid-May with or without 2,4-D application prior to grazing; and 15 days starting mid-April (no herbicide)] grazing systems based on forage utilization and impact to Artemisia absinthium (absinth wormwood) in a tall grass pasture of Eastern South Dakota. Grass …


An Economic Analysis Of High-Intensity, Short-Duration Grazing Systems In South Dakota And Nebraska, Larry Janssen, Bronc Mcmurtry, Matthew Stockton, Alexander Smart, Sharon A. Clay Jan 2015

An Economic Analysis Of High-Intensity, Short-Duration Grazing Systems In South Dakota And Nebraska, Larry Janssen, Bronc Mcmurtry, Matthew Stockton, Alexander Smart, Sharon A. Clay

Agronomy, Horticulture and Plant Science Faculty Publications

Four different grazing systems: two rotational systems, a continuous grazing system, and a modified high-intensity, short-duration (mob) system were evaluated from an economic return and risk perspective. Stocking rates and average daily gains (ADG) were obtained from 2011 – 2014 from university ranch experiments in northern Nebraska. Simulation models were used to examine net returns and risk in each system and rank systems according to risk preferences. A twice through rotational grazing system was most profitable. Mob grazing was the least preferred, although when risk aversion increased, it rose in preference. Mob grazing could be profitable if adjustments increased animal …


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 …