Using Digital Movie Making to Teach Theories in Range Science

Learning complex theories in Range Science can be aided by having students use digital movie making technology. The objectives of this paper were to 1) describe the digital movie making process and 2) provide a qualitative assessment of its use in learning conceptual subject matter. Students were instructed in the use of digital movie making software and the process to create a digital movie describing the state-and-transition plant succession model. Ninety percent of the students thought that the movie making project helped them better understand the state-and-transition plant succession model. Students enjoyed learning the new technology and 40% said they would likely use it in the future. Digital movie making was a successful method to teach complex theories, such as the state-and-transition plant succession model

The Use of Turnips for Extending the Grazing Season

The use of short-season crops, such as turnips, is effective for extending the grazing season, following the harvest of small grains. A system of double cropping works particularly well if the intent is to provide a break in crop rotation. Turnips, which are in the brassica family, are fast growing and tolerate cold temperatures. Therefore, they are good for providing high quality and quantity forage for grazing livestock well into the fall (Figure 1)

Impact of Mature, Female Eastern Red Cedar (Juniperus Virginiana L.) Trees on Soil Seed Bank in the Mixed-Grass Prairie of the Northern Great Plains

Eastern red cedar (ERC) (Juniperus virginiana L.) trees are invading prairies throughout the Great Plains due to fire suppression and overgrazing. This encroachment poses a threat to native plant communities in terms of their reproduction, regeneration, diversity, and invasiveness. It is unknown how ERC trees impact belowground propagules in the mixed-grass prairie and how it may alter heterogeneity. The objective of this study was to evaluate how mature female ERC trees impact the soil seed bank composition. In October 2020 in southcentral South Dakota ten female ERC trees with canopy diameters = 5-10 m, similar environmental characteristics, and isolated from other large trees were selected for soil seed bank sampling at four treatments: under canopy (UC), dripline (DL), two meters outside dripline (2M), and grassland control (GL). Four cardinal direction transects extended from each tree stem where a soil core (10 cm dia. x 10 cm depth) was sampled at the four treatment distances, totaling 16 cores per tree and 160 cores overall. Soil cores were sieved through a 2 mm sieve, planted on 2 cm of Miracle Gro® potting soil, and grown in a greenhouse at 23 ± 3 ⁰C under 16-hour light. A total of 12,563 seedlings emerged consisting of 26 families, 75 genera, and 89 species. Plant community analyses were conducted in PC – ORD using nonmetric multidimensional scaling and multi-response permutation procedures for treatment comparisons. Seed bank composition significantly differed among treatments (P = 0.0139). We found significant differences in seed bank composition between UC and 2M (P = 0.0079) and between UC and GL (P = 0.0055), which were primarily due to more introduced annual forbs found under the ERC canopy compared to 2M and GL; other comparisons were not significant. Our results suggest that the impact of female ERC trees on soil seed bank composition is limited within the canopy of ERC with no difference detected 2M and beyond

Morphological Development of Switchgrass as Affected by Planting Date

Late-spring and early-summer plantings of warm-season grasses often fail, due to dry soil conditions and competition from annual grass and broadleaf weeds. The objective of this study was to compare the morphological development of switchgrass (Panicum virgatum L.) planted in early, mid, and late spring in eastern Nebraska. This study was conducted in 1994 and 1995 at Lincoln, NE, on a Kennebec silt loam (fine-silty, mixed, mesic Cumulic Hapludolls). \u27Blackwell\u27 and \u27Trailblazer\u27 switchgrass were planted in mid-March, late April, and late May using a single-row, precision grass-seed cone planter to a depth of 0.6 to 1.3 cm at 98 pure live seed per linear meter of row in a split-plot design. Twenty seedlings from each plot were excavated to a depth of 20 cm with a spade. Seedling morphological parameters measured were mean stage count root (MSCR) and shoot (MSCS), leaf area, shoot weight, and primary and adventitious root weight. Plots were sampled every 10 d following the first sample date. In 1994, seedlings from the March planting date were more advanced morphologically in MSCR and MSCS, had accumulated 2.5 times more leaf area, and about 3 times more shoot and adventitious root mass than the April planting date when sampled from late May to late June. In 1995, seedlings from the March planting date generally were more advanced morphologically in root and shoot development, had accumulated 2 to 12 times more leaf area, had 2 to 10 times more shoot mass, and had 2 to 33 times more adventitious root mass than the April or May planting dates at the sample periods from early June to mid-July. We suggest that switchgrass should be planted in early spring instead of in late April and May, as suggested by previous research

Mob Grazing as a Method of Weed Control in South Dakota

Mob grazing is a grazing system that uses very high stocking densities of 100,000 pounds per acre or more for short durations of a few hours to one day in small paddocks. Mob grazing has been suggested to increase vegetation usage and minimize selective grazing behavior compared with lower stocking densities in rotational systems. Decreased selectivity increases grazing pressure on plants, such as spiny thistles and tough, woody brush, typically avoided by herbivores. The objective of this project was to determine effects of mob grazing cattle on the selected invasive weeds: musk thistle (Carduus nutans), absinth wormwood (Artemisia absinthium), and buckbrush (Symphoricarpos occidentalis). Cooperating producers in Hayti, Selby, and Chamberlain, South Dakota named their most problematic pasture weeds, listed above. The Hayti site consisted of mob grazed, rotationally grazed, and spray/rotationally grazed treatments; Selby of rotationally grazed and mob grazed treatments; and Chamberlain of ungrazed and mob grazed treatments. The specific problematic weed at each site was permanently tagged along transects. Measurements of surrounding vegetation and weeds were taken before and after grazing. Initial results quantified a decrease in weed volume and height in mob grazed systems; a decrease in surrounding vegetation height, but not weed volume in rotational pastures; and an increase in vegetation height and weed volume for the ungrazed pasture. These data indicate that mob grazing may be a viable method of weed control in South Dakota grazinglands

Effect of Grazing, Mowing, or Herbicide on Leafy Spurge Control

Leafy spurge (euphorbia esula L.) is an herbaceous perennial which is deep rooted and can reproduce by seeds and rhizomes. First introduced into North America in the 1800’s from Europe, it now covers 25 states in the USA and several provinces in Canada. It is a major concern in North Dakota, South Dakota, Wyoming, Montana, and Nebraska. Leafy spurge is considered a noxious weed that is extremely competitive, establishing itself in pastureland and roadsides. Bangsund et al. (1997) estimated that by 2005, uncontrolled leafy spurge acres would reach 18.5 million in the Northern Great Plains. The cost of leafy spurge is estimated to be in the 100’s of millions of dollars due to lost grazing through a reduction of available AUM’s (animal unit months) and treatment costs which may not be economically feasible. This is impart due to the fact that cattle avoid eating leafy spurge because of post-ingestive negative feedbacks from plant toxins (Kronberg et al., 1993) and avoid grazing in areas where leafy spurge canopy cover is high, thus reducing grass production and utilization (Hein and Miller, 1992). Do to the high costs of herbicides and their ineffective control in the long-term (Lym and Messersmith, 1985), biological controls such as sheep and goats as well as the flea beetle have become more popular tools in controlling leafy spurge (Bangsund et al., 2000). In a pasture setting sheep and goats readily graze forbs and do not experience the build up of toxins that cattle do, making small ruminants ideal biological controls for leafy spurge. The object of this trial was to measure the effectiveness of various control methods on leafy spurge

Drought and Stocking Rate Effects on Forage Yield from Western South Dakota Rangelands

The vegetation of rangelands in a large portion of western South Dakota is an overstory of cool-season grasses such as western wheatgrass and green needlegrass and an understory of warm-season grasses such as blue grama and buffalograss (Fig 1). In semi-arid environments, precipitation is the main factor that determines forage production. Many western South Dakota counties receive less than 17 inches of annual rainfall, with 75% occurring between April and October. Pastures are usually managed as large units (more than 160 acres) because fencing and water developments are costly. Regrowth is usually limited to the spring, and 90% of forage is produced by July 1 (Heitschmidt 2004). Most grazing systems are continuous season-long grazing or simple rotational grazing with less than eight pastures

Managing Smooth Bromegrass Pastures in South Dakota

Smooth bromegrass is a cool-season grass introduced into the U.S. in the latter part of the 19th century. Because of its highly developed root system, smooth bromegrass is resistant to wide temperature extremes and extensive drought. This resistance has allowed it to become a dominant species in pastures and on native rangeland in eastern and central South Dakota. It is a leafy and sod-forming perennial that spreads aggressively through seeds and rhizomes and establishes well on deep, well-drained silt, clay loam, or sandy soils (Fig 1)

Optimal Placement of Off-Stream Water Sources for Ephemeral Stream Recovery

Uneven and/or inefficient livestock distribution is often a product of an inadequate number and distribution of watering points.Placement of off-stream water practices (OSWP) in pastures is a key consideration in rangeland management plans and is criticalto achieving riparian recovery by improving grazing evenness, while improving livestock performance. Effective OSWPplacement also minimizes the impacts of livestock use radiating from OSWP, known as the ‘‘piosphere.’’ The objective of thisstudy was to provide land managers with recommendations for the optimum placement of OSWP. Specifically, we aimed toprovide minimum offset distances of OSWP to streams and assess the effective range of OSWP using Normalized DifferenceVegetation Index (NDVI) values, an indicator of live standing crop. NDVI values were determined from a time-series of SatellitePour l’Observation de la Terre (SPOT) 20-m images of western South Dakota mixed-grass prairie. The NDVI values inephemeral stream channels (in-channel) and uplands were extracted from pre- and post-OSWP images taken in 1989 and 2010,respectively. NDVI values were normalized to a reference imagine and subsequently by ecological site to produce nNDVI. Ourresults demonstrate a significant (P,0.05) increase in the nNDVI values of in-channel vegetation within 1 250 m of OSWPfollowing their implementation. The area of piospheres (n¼9) increased with pasture size (R2¼0.49,P¼0.05) and increasedwith average distance to OSWP in a pasture (R2¼0.43,P¼0.07). Piospheric reduction in nNDVI was observed within 200 m ofOSWP, occasionally overlapping in-channel areas. The findings of this study suggest placement of OSWP 200 to 1 250 m fromstreams to achieve optimal results. These results can be used to increase grazing efficiency by effectively placing OSWP andinsure that piospheres do not overlap ecologically important in-channel areas