Saline Experimental Range Dormant Season Wildfire: Short-Term Effect on Forage Production and Plant Composition

Rangeland wildfires in the southern plains may occur any time of year, but the low hu­midity, increasing temperatures, and dry and abundant fuel load of late winter and early spring can result in greater wildfire occurrence and severity. Fires that occur before the growing season remove standing residual vegetation and greatly reduce litter cover, so the soil surface may be left bare for several weeks or months before the onset of new pas­ture growth. Exposure of plant buds to cold temperatures during dormancy, soil water evaporation, and soil crusting from the force of falling precipitation and puddling may lead to the eventual loss of plant density and available soil moisture for plant growth following wildfire. Information collected from a previous wildfire that occurred during mid-March at the Kansas State University Agricultural Research Center–Hays showed that forage production was significantly reduced for two years following the fire. How­ever, timing and conditions leading up to wildfires and conditions following wildfires may allow pastures to respond to each fire differently. In the week of March 5-11, 2017, several wildfires ignited throughout central and western Kansas. One of those fires was the largest known wildfire in Kansas history, the Starbuck Fire, that consumed more than 460,000 acres of Kansas land in Clark, Meade, and Comanche counties. Another fire ignited on the Kansas State University Saline Experimental Range (SER) in north­east Ellis County on March 7, 2017

Legume establishment and persistence at sites varying in landscape position, grazing method, and soil characteristics

Iowa pastures are diverse in the landscapes and soil conditions present within small area units. Introducing legumes into these areas has the potential to improve seasonal distribution and quality of the pasture forage. This study was performed to quantify the spatial and temporal variation in legume contribution to the plant community when seeded into established cool-season grass pastures. Pastures were seeded with a mixture of eleven legumes and then divided into three grazing methods (non-grazed, continuous, and rotational), with each grazing method containing five landscape positions (upland, sideslope, bottomland, opposite sideslope, and opposite upland). Legume dry matter composition, legume species richness, legume diversity, and forage quality was determined during the grazing season and associated with site soil characteristics. Sideslope positions had greater legume dry matter composition (161 g kg-1) than either the upland (62 g kg-1) or bottomland landscape positions (7 g kg -1), and legume concentrations increased as the growing seasons progressed in the grazed treatments. Legume species richness also was greater for sideslope landscape positions. Legume dry matter composition showed a strong, positive linear relationship to species richness in continuous, rotational, and non-grazed treatments (r2 = 0.77, 0.84, and 0.74), and may potentially be utilized as a tool to estimate the need for re establishment in these pastures. Legume dry matter diversity using the Shannon-Wiener index was greatest for grazed pastures, but was positively linearly related to legume dry matter composition in only rotationally grazed paddocks (r2 = 0.88). Upland and bottomland sites with the greatest total available dry matter herbage production potential contained the lowest legume concentrations and legume herbage. Forage NDF was lowest and IVDMD was greatest on sideslopes (527 g kg-1, 630 g kg-1) compared to uplands (552 g kg-1, 608 g kg-1) and bottomlands (568 g kg-1, 560 g kg-1 ). Of all spatial and temporal variables, land slope best explained the variation in legume dry matter composition (r2 = 0.66) and species richness (r2 = 0.75). Competition resulting from the greater grass component at lesser slopes appeared to be a limiting factor for legume establishment. Land slope is easily quantified, and could serve as a basis for pasture division for differential fertilization, seeding, and grazing management

Herbicide Activity on Old World Bluestems

Two main species of old world bluestems (OWB), yellow bluestem (Bothriochloa ischaemum) and Caucasian bluestem (Bothriochloa bladhii), have encroached on rangelands, pastures, and road right-of-ways in Kansas. Patches of these OWB have been shown to reduce species diversity and abundance at multiple trophic levels, and pose a long-term threat to native plant, insect, rodent, and grassland bird populations. These OWB species are utilized by cattle early in the growing season, directly following prescribed burns, and during droughts when other forages lack water uptake and may go dormant. However, these OWB species mature more quickly than native grass species and quickly form stem tissue, thus losing palatability to grazing animals rather rapidly compared to native grass species. In native pastures where OWB has invaded, native species may become overutilized because animals avoid the OWB. This weakens the native grasses and allows OWB to have a competitive advantage for moisture and nutrient resources. Over time, patches of OWB have expanded from 2.5 to 3.5 times their original patch size in 9 years, or a 15% annually compounded patch growth rate, when left uncontrolled. Several herbicides have been analyzed for OWB control, but glyphosate and imazapyr are the two herbicides that in the past have been shown to reduce OWB abundance most effectively in pastures. However, other herbicides with new label information for use in different forms of grassland or recreation areas may also have some activity on OWB and provide control. This study was performed to test several alternative herbicides with no known prior history of evaluation for control of OWB

Reclaiming Old World Bluestem Pasture with Imazapyr Application and Native Grass Overseeding

Old world bluestems (OWB), mainly Caucasian bluestem (Bothriochloa bladhii) and yellow bluestem (Bothriochloa ischaemum) introduced from parts of eastern Europe, Asia, Africa, and Australia, have been shown to reduce abundance and diversity of some insect and wildlife species compared to native grasses when these OWB grasses form dense stands. These OWBs have been invading native pastures in the southern Great Plains and are rapidly increasing in the amount of area occupied in Kansas. Two landowners purchased pasture property in Ellsworth County, KS, and observed that Caucasian old world bluestem had increased in the pasture significantly over the course of several years. They developed a plan with local partners to reclaim the pasture back to native grass and forb dominance in an effort to improve wildlife habitat and cattle grazing on the property

Using Modified Intensive Early Stocking for Cow/Calf Production

Intensive early stocking (IES) was introduced nearly a half century ago in eastern Kan­sas and has since been adopted as a major management tool to increase animal produc­tion, efficiency of production, and economic return on tallgrass rangelands. These in­creases have come almost exclusively by using IES with young stocker animals. Intensive early stocking and its gains have been proven effective repeatedly in published research. A similar modified IES (MIES) system has increased production efficiency of stocker animals on western Kansas rangelands. Perennial grassland acres for cattle produc­tion, as well as cattle numbers, are declining. Using management practices that mimic the MIES system to increase beef cattle stocking density for breeding herds may allow producers to maintain or increase cow numbers for beef production on fewer peren­nial grassland resources. The objective of this project is to compare cow and calf growth and performance in traditional continuous season-long stocking (SLS) and MIES beef production systems

Grazing wheat did not reduce beef cow pregnancy rates

Beef producers can lower feed costs by extending the grazing period and reducing the need for harvested forages. Complementary forage systems extend the native range grazing season; wheat pasture is common in the southern portion of the High Plains. Anecdotal reports have been made concerning lowered fertility in beef cows bred on lush forage such as wheat pasture; however, ruling out other possible causes of low fertility is difficult. In lactating dairy cows, fertility is lower during consumption of high-protein diets that result in high blood urea nitrogen content. Lower uterine pH that in turn affects embryo survival is thought to be the general mechanism responsible for lower fertility. Little information is available on the fertility of beef cows consuming high-protein diets. Therefore, the objective of this study was to compare pregnancy rates of springcalving cows consuming either wheat pasture or native range before and during the early breeding season

An Efficient Stocking Strategy for Grazing Replacement Heifers

Even though Kansas native rangelands often have steep slopes or shallow soils not con­ducive to many other uses other than livestock grazing, native rangeland and perennial grassland acres in Kansas have been declining. Cropland acreage over this same time frame has increased, and rangelands have also become more fragmented by small ranch­ettes and urbanization. Producers may be looking to increase production efficiency on a shrinking forage land base. The use of intensive early stocking (IES) is one of the most efficient stocking strategies to produce beef on rangeland acres. The IES strategy has been widely used in eastern Kansas and is capable of increasing beef production by 30–40% compared to continuous season long stocking (SLS). In western Kansas, IES and continuous SLS have resulted in similar beef production. However, a modified IES (MIES) system, which combines greater early season animal density on high-quality forage of IES and late season individual animal selectivity for a high-quality diet of SLS, has increased beef production by 26% compared to continuous SLS alone on western Kansas rangelands. Even with this significant increase in production efficiency, stocker production is largely overshadowed by cow/calf production in terms of acres grazed in western Kansas. The question then arises, can the efficiencies of greater beef stocker production from modified IES be utilized with reproductive animals of the cow/calf production system? The purpose of this study was to compare the use of continuous SLS and MIES in a replacement heifer system for western Kansas

Mixed-Grass Vegetation Response to an Extreme Wildfire Event

The wildfires of the 2021-2022 dormant season in Ellis, Osborne, Rooks, and Russell counties occurred under extreme weather conditions. However, most every dormant season contains conditions suitable for wildfires to occur: dried vegetation, low humidity, and potential for days of elevated temperatures and winds. A portion of the 122,000-acre area that burned in the December 2021 Four County Fire also burned in March 2017 during the dormant season. Dormant-season wildfire removes benefi­cial vegetative soil cover during the dormant season, and has ecological and financial impacts in the following growing seasons. Prior published dormant-season wildfire data showed that yield reductions the growing season after the fire ranged from 25% to 65%, depending on the time, location, and the main grass species consumed in the fire. Less soil cover and less production in the years after the fire may require lower stocking rates, which ultimately results in lower potential income. The Four County Fire burned approximately 12% of the range and pasture acres in these four counties. Therefore, fires of this magnitude have significant ecological and financial impacts on regional commu­nities. To date, only a few historic wildfires in northwest Kansas have data available regarding rangeland response to those wildfires. This study was designed to provide producers with information for ecological and grazing animal planning for the years following dormant season wildfires in western Kansas

Vegetation and Animal Production in Pastures Sprayed for Western Ragweed Control

Western ragweed (Ambrosia psilostachya) is a common native forb found throughout Kansas native rangelands and in some seeded pastures. Over time, western ragweed can form dense colonies from growth of lateral creeping rootstalks with multiple buds that can initiate new growth and form an upright stem and plant. Past research has shown that western ragweed does not compete with native grass production until ragweed contributes over approximately 35% of the forage dry matter of a pasture area. Cattle have utilized western ragweed in past long-term historical grazing trials. In a previous long-term trial at Hays, KS, western ragweed was the most common forb found in light and moderately stocked pastures. Frequency of western ragweed was greatest in pastures with light stocking rates, and frequency of western ragweed declined by nearly 50% in moderately stocked pastures because animals utilized the western ragweed. In heavy stocking rate pastures, western ragweed was found in only trace amounts because of greater animal use. However, producers still question if cattle utilize western ragweed and achieve adequate gains in pastures with high western ragweed populations. Therefore, we conducted a grazing trial to determine if controlling western ragweed in pasture improved stocker animal gains compared to pastures with no ragweed control

Interseeding Sorghum-Sudangrass into Perennial Cool-Season Western Wheatgrass Pasture

Conversion of pastureland into cropland has occurred at a rapid rate on the Great Plains. A reduction in total acreage of pastureland from this conversion has resulted in a decline of total numbers of beef cows in the same region. One method to mitigate the decline in cow numbers is to increase the carrying capacity of the remaining pastureland acres. To achieve this goal, a study was conducted to introduce warm-season annual grass species into perennial cool-season grass pastures to increase dry matter production during the mid-summer time period that perennial cool-season grasses would be most dormant. An increase in production during this time period could result in a significant overall increase in total land area production