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

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

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)

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

Switchgrass Seedling Development as Affected by Seed Size

Seed size has been associated with early seedling vigor (i.e., germination rate, emergence rate, and growth) in grasses. This study was conducted to compare seedling development over a 60-d period in the field as affected by heavy seed (HS) (0.19 to 0.21 g 100 seed-1) and light seed (LS) (0.13 to 0.16 g 100 seed-1) of \u27Blackwell\u27 and \u27Trailblazer\u27 switchgrass (Panicum virgatum L.). The experiment was conducted in 1995 and 1996 at Lincoln, NE, on a Kennebec silt loam (fine-silty, mixed, superactive, mesic Cumnlic Hapludolls). The experimental design was a randomized complete block with four replicates. Seed was separated into two sizes using a South Dakota seed blower. Seed was planted into rows at a rate of 100 pure live seed per meter of row. Plants were excavated and evaluated for shoot weight, leaf area, and root weight. Shoot and root systems were morphologically staged four times during the summer. Seed size differences in switchgrass appeared to produce only slight differences in morphological development of shoot and root systems, leaf area, shoot weight, and adventitious root weight from seedling emergence to 6 wk of growth. Adventitious roots formed more quickly on seedlings from heavier than lighter seed, but the advantage to seedling establishment was minimal even when soil moisture appeared to be lacking. By 8 to 10 wk after emergence, growth and development of LS seedlings were similar to HS seedlings. Once seedlings formed two or more adventitious roots, seed size no longer affected establishment and growth. Seed size in switchgrass appears to have a minimal long-term effect on growth and development of seedlings

After Wildfire: Range Recovery

In the grip of drought, livestock producers often must deal with the additional impact of wildfire. While drought conditions develop gradually and can be anticipated, losses due to wildfire are sudden and devastating

Demonstration-Based Education Generates Behavior Change Related to Conservation Practices

Getting agricultural producers to make changes to their operations is difficult, especially related to complex systems such as the water cycle on managed agricultural lands. We surveyed participants who had watched a rainfall simulator demonstration during the summer of 2015. Results indicate that the demonstration was effective in providing educational outreach on the impact of the water cycle and prompting the adoption of conservation practices and monitoring techniques among producers. The study reinforces the importance in conservation education of learning experiences involving simulation, observation, and group discussion. Our findings may be applicable not only to Extension professionals working with agricultural producers but also to those involved in encouraging conservation practices among other audiences

EFFECTS OF HERBICIDES AND GRAZING ON FLORISTIC QUALITY OF NATIVE TALLGRASS PASTURES IN EASTERN SOUTH DAKOTA AND SOUTHWESTERN MINNESOTA

Historic herbicide use and grazing have influenced natural diversity and quality of native pasturelands in the Great Plains. Floristic quality assessments are useful to assist agencies in prioritizing conservation practices to enhance native grasslands. The objective of this study was to determine the effects of past land-use practices on the floristic quality of remnant native pastures in eastern South Dakota and southwestern Minnesota. Floristic quality assessments were conducted on 30 native pastures and categorized by past management practices (herbicide application and grazing intensity). Mean coefficient of conservatism (C) and floristic quality index (FQI) were calculated for each site~Results showed that increased herbicide use and grazing intensity resulted in a lower species richness, forb C ,and FQI. However, grass and grasslike plants were minimally affected. Pastures that were infrequently sprayed with herbicides and lightly grazed consistently had the highest species richness, C ,and FQI. Pastures with no grazing produced similar values to those with moderate grazing. Pastures managed as preserves or wildlife habitat areas had higher FQI than those managed for livestock grazing. The implications of this study should further help ecologists and managers understand the positive and negative effects of grazing practices and herbicide application on tallgrass prairie remnants

EFFECTS OF HERBICIDES AND GRAZING ON FLORISTIC QUALITY OF NATIVE TALLGRASS PASTURES IN EASTERN SOUTH DAKOTA AND SOUTHWESTERN MINNESOTA

Historic herbicide use and grazing have influenced natural diversity and quality of native pasturelands in the Great Plains. Floristic quality assessments are useful to assist agencies in prioritizing conservation practices to enhance native grasslands. The objective of this study was to determine the effects of past land-use practices on the floristic quality of remnant native pastures in eastern South Dakota and southwestern Minnesota. Floristic quality assessments were conducted on 30 native pastures and categorized by past management practices (herbicide application and grazing intensity). Mean coefficient of conservatism (C) and floristic quality index (FQI) were calculated for each site~Results showed that increased herbicide use and grazing intensity resulted in a lower species richness, forb C ,and FQI. However, grass and grasslike plants were minimally affected. Pastures that were infrequently sprayed with herbicides and lightly grazed consistently had the highest species richness, C ,and FQI. Pastures with no grazing produced similar values to those with moderate grazing. Pastures managed as preserves or wildlife habitat areas had higher FQI than those managed for livestock grazing. The implications of this study should further help ecologists and managers understand the positive and negative effects of grazing practices and herbicide application on tallgrass prairie remnants

Predicting Forage Production, Stocking Rate, and Beef Production in Eastern South Dakota: A Case Study

In the summer of 1999, the Hand and Hyde County Bootstraps group met to form a working group to better understand “Management Intensive” Grazing (MIG) systems. From this working group of ranchers and state and federal agency personnel, evolved a goal to establish six demonstration sites in South Dakota (Figure 1). In 2000, the first demonstration site was established by Jim Faulstich near Highmore, SD in Hyde County. This site is a 320 acre pasture dominated by native mixed-grass prairie vegetation with some introduced species such as smooth bromegrass, Kentucky bluegrass, and crested wheatgrass. The pasture was fenced into 21 paddocks and water was developed using aboveground pipeline. Cattle weights, forage biomass, forage utilization, and climate data were measured. This report summarizes the first six years of the study and provides some predictive tools for forage production, stocking rate, and beef production based on climate data