Grazing Lands and Soil Carbon Storage

On March 31, 2009, a draft discussion of the American Clean Energy and Security Act of 2009 was released to the public. The bill contains four sections addressing: clean energy; energy efficiency; reducing global warming pollution; and transitioning to a clean energy economy. Section 3 contains a description of the proposed cap-and-trade program designed to reduce industrial emissions of greenhouse gases (GHG) including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydro-fluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6) and nitrogen trifluoride (NF3). Agricultural sources, although largely diffuse and not regulated directly by the bill, account for 8 percent of U.S. annual GHG emissions (U.S. EPA, 2008). The agricultural community can address climate change by reducing its emissions and adopting management practices that enhance storage of carbon in soil. The objective of this article is to describe the effects of grazing land management on soil carbon storage

Shaping the Cross Timbers with Fire and Grazing

Recently, our agricultural research team has been asked to provide talks during tours of our Oswalt Road Ranch. The Oswalt Road Ranch is a 4,992-acre property in Love County, Okla., willed to us by D. Joyce Coffey. The Noble Foundation took full control of the property in 2000. The ranch is a valuable piece of property because of its unique natural beauty and potential to support livestock production and wildlife habitat. On the tours, we have been showing off our new state-of-the art livestock handling facilities and providing information about results from recent research on by-product feeds, the Noble Foundation stocker cattle receiving program, white-tailed deer movements and management of rangelands. As a forage agronomist, I am involved in our current and future plans for the management of the range and forestland covering this property. Today, I\u27m going to tell you more about this property, explain why it has unique value as a native ecosystem, illustrate how it fits as a component of the natural heritage of Oklahoma, and discuss our plans for managing this property to enhance its value for wildlife and cattle, while hopefully providing some insight on how you might manage similar properties

Distribution of legumes and plant diversity in pastures that vary in landscape position and grazing management

Legumes improve the quality and production of forage in pastures. Their distribution and abundance, however, depend on landscape position and grazing management, and their productivity, as percentage of dry matter, is correlated positively to the number of legume species found across pasture landscapes. The objectives of my dissertation were to: (i) evaluate why legumes exhibit site-specific adaptations in pastures; (ii) determine the effect of landscape position and grazing management on plant species composition and diversity; and (iii) quantify the relationship between the distribution and abundance of legumes and gradients of slope and soil electrical conductivity in pastures. I addressed these objectives with three experiments. In the first experiment, I measured the emergence and survival of legumes on summit and backslope landscape positions under varying N fertilization and sward cutting height treatments. I found legume establishment on summit landscape positions is limited by poor survival of seedlings. On backslopes, grass competition is less, and legume establishment is successful in swards cut at 5 cm. In the second experiment, I used a multi-scale sampling method to measure the effects of landscape position and grazing management on the occurrence and diversity of legume and grass species in pastures. I found legume and grass species diversity was greatest on backslope landscapes. Diversity increased with scale but at a greater rate in grazed than nongrazed pastures. Increasing sample scale enables greater detection of minor forage species. In the final experiment, I found legumes in pastures, as a % of vegetative cover, are most successful at 15 to 20% slopes and intermediate values of soil EC. Competition from grass limits the occurrence of legumes at slopes \u3c10% and at low and high values of soil EC. The results from these studies support the hypotheses that the distribution of legumes and plant diversity in pastures is strongly related to topography, and that sound grazing management is essential to the maintenance of legumes and plant diversity in pastures. I recommend a diverse assemblage of legumes be seeded on backslope landscape positions to optimize pasture production and the availability of nutrients over space and time

Forage Yields from 2006-2007 Annual Ryegrass Variety Trial

Introduction: In an effort to assist livestock producers in Oklahoma and Texas judge variety performance, the Noble Foundation has held trials to determine forage yields of commercially available varieties and experimental strains of annual ryegrass. The objective of this report is to summarize forage yields from the 2006-2007 trial. Materials and Methods The test was conducted on a Wilson silt loam soil at the Noble Foundation Headquarters Farm near Ardmore, Okla. The trial consisted of 37 entries; 28 were commercially available varieties and nine were experimental strains. Twelve sources contributed entries to the trial (Table 1). The entries were seeded in a clean-tilled seedbed on Sept. 26, 2006. Each entry was drilled in 5- by 15-foot plots, in 7-inch rows, at 25 lbs/ac (pure live seed basis) at a ½-inch planting depth with a HEGE 500 drill. Fertilization consisted of preplant incorporation of 120 lbs N/ac and 23 lbs P205/ac on Sept. 19, 2006, and a topdress application of 80 lbs N/acre on March 1, 2007. Broadleaved weeds were controlled with an application of 2,4-D amine at one pt/ac on Jan. 29, 2007. Plots were harvested with a HEGE sickle bar forage plot harvester at a 3-inch height on Feb. 23, March 26, April 9 and May 14, 2007. The trial was a randomized complete block with three replications. Data were analyzed with the general linear models procedure in SAS (Statistical Analysis Software, Cary, N.C.), and means were separated by the least significant difference (LSD) method (P ≤ 0.05). Results and Discussion Growing conditions were good for the trial. After a slow start following severe drought in the spring and summer of 2006, precipitation from October 2006 through April 2007 was near the 106-year average for Ardmore (Table 2). Rainfall increased substantially in May, toward the end of the trial, and exceeded the 106-year annual average by 2.7 inches

Grazing Lands and Soil Carbon Storage

On March 31, 2009, a draft discussion of the American Clean Energy and Security Act of 2009 was released to the public. The bill contains four sections addressing: clean energy; energy efficiency; reducing global warming pollution; and transitioning to a clean energy economy. Section 3 contains a description of the proposed cap-and-trade program designed to reduce industrial emissions of greenhouse gases (GHG) including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydro-fluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6) and nitrogen trifluoride (NF3). Agricultural sources, although largely diffuse and not regulated directly by the bill, account for 8 percent of U.S. annual GHG emissions (U.S. EPA, 2008). The agricultural community can address climate change by reducing its emissions and adopting management practices that enhance storage of carbon in soil. The objective of this article is to describe the effects of grazing land management on soil carbon storage

Shaping the Cross Timbers with Fire and Grazing

Recently, our agricultural research team has been asked to provide talks during tours of our Oswalt Road Ranch. The Oswalt Road Ranch is a 4,992-acre property in Love County, Okla., willed to us by D. Joyce Coffey. The Noble Foundation took full control of the property in 2000. The ranch is a valuable piece of property because of its unique natural beauty and potential to support livestock production and wildlife habitat. On the tours, we have been showing off our new state-of-the art livestock handling facilities and providing information about results from recent research on by-product feeds, the Noble Foundation stocker cattle receiving program, white-tailed deer movements and management of rangelands. As a forage agronomist, I am involved in our current and future plans for the management of the range and forestland covering this property. Today, I\u27m going to tell you more about this property, explain why it has unique value as a native ecosystem, illustrate how it fits as a component of the natural heritage of Oklahoma, and discuss our plans for managing this property to enhance its value for wildlife and cattle, while hopefully providing some insight on how you might manage similar properties

Nitrogen Input Effects on Herbage Accumulation and Presence of Pasture Plant Species

Long-term responses of pasture plant species to management strategies that vary amount and form of N inputs form a knowledge gap. Our objective was to determine how supplementation of grazing beef cattle (Bos taurus) with corn (Zea mays L.) dried distillers grains plus solubles (DDGS) in unfertilized pasture (SUPP) affects annual herbage accumulation and presence of plant species and functional groups relative to unsupplemented beef cattle on unfertilized (CONT) and N-fertilized (FERT) smooth bromegrass (Bromus inermis Leyss.) pasture. We addressed this objective in the sixth (2010) and seventh (2011) years of a long-term experiment in eastern Nebraska, where N input from DDGS supplementation and urea fertilizer averaged 0, 43, and 90 kg ha–1 yr–1 within CONT, SUPP, and FERT, respectively. For these years, annual herbage accumulation averaged 6.87, 6.80, and 10.58 Mg ha–1 (LSD = 1.49) and 66.5, 66.2, and 76.0% of herbage accumulated by 25 June (LSD = 5.3) in CONT, SUPP, and FERT, respectively. Smooth bromegrass occurred in 99.8% of 0.1-m2 pasture quadrats regardless of treatment. Cessation of N fertilizer input, however, increased presence of annual foxtail (Setaria spp.), annual graminoids, and annuals among quadrats in CONT relative to FERT. Supplementation of DDGS, while shown in previous studies to improve weight gains and N use efficiency in cattle, supplied enough N through excretion to provide an intermediate level of resistance to annual weeds. Nitrogen excreted from cattle supplemented with DDGS, however, did not aff ect herbage accumulation in subsequent years

Managing Nitrogen and Phosphorus Nutrients for Switchgrass Produced for Bioenergy Feedstock in Phosphorus-Deficient Soil

There is limited information available explaining the agronomic and economic relationships between yield and nitrogen and phosphorus applications to growing switchgrass produced in phosphorus-deficient soils. The objective of this study was to determine the effects of nitrogen and phosphorus fertilizers on feedstock yield and measures of expected total cost, gross revenue, net return, and breakeven price of feedstock produced in phosphorus-deficient soils in the southern Great Plains. Data were collected from a three-year, two-location agronomic field study conducted in south-central Oklahoma. Two discrete nitrogen treatments (0 and 134 kg ha-1) and four discrete phosphorus treatments (0, 30, 60 and 90 kg ha-1) were randomly assigned to small plots arranged in a randomized complete block designed (RCBD) study. Random effects mixed ANOVA models were used to estimate the effects of nitrogen, phosphorus and nitrogen by phosphorus interactions on feedstock yield and the economic variables specified. Results showed that, on average over site-years, switchgrass yield increases from 10.5 to 12.3 Mg ha-1 with the highest (101-kg ha-1) treatment; however, we found no statistical difference in net profitability between phosphorus treatments. Yield and net return did respond significantly to 135 kg-1 of N ha-1. Our results suggest that phosphorus-deficient soils do not seem to have the same impact on switchgrass yield and profitability as they do for the yields and profitability of other crops traditionally grown in this region.bioenergy feedstock, economics, phosphorus-deficient soils, nitrogen, switchgrass, Crop Production/Industries, Environmental Economics and Policy, Production Economics,

Seeding Rate Effects on Forage Mass and Vegetation Dynamics of Cool-Season Grass Sod Interseeded with Sorghum-Sudangrass

Interseeding annual warm-season grasses into perennial cool-season grasses has the potential to increase summer forage mass and nutritive value. Knowledge of how seeding rate affects annual warm-season grass establishment, forage mass, and vegetation dynamics remains limited. From 2016–2017, we conducted a field experiment evaluating the effects of seeding rates on sorghum-sudangrass (Sorghum bicolor x S. bicolor var. sudanense) density and forage mass and on the frequency of occurrence of plant species in cool-season grass sod in Lincoln, NE. The experiment had a completely randomized design consisting of six replicates of four seeding rates [0, 14, 28, and 35 kg pure live seed (PLS) ha-1] in sod mowed at a 2.5-cm height and one unseeded, non-mowed control treatment. Sorghum-sudangrass establishment increased with seeding rate from an average of 20 to 45 plants m-2 as the seeding rate increased from 14 to 35 kg PLS ha-1. Forage mass depended on a seeding rate x harvest interaction, showing positive linear and cubic responses to seeding rate in consecutive harvests at 45 and 90 d after interseeding. To increase forage mass in perennial cool-season grass sod, producers should interseed sorghum-sudangrass with at least 28 kg PLS ha-1. One-time seedings into cool-season, perennial grass sod have no residual effects on subsequent forage mass and vegetation dynamics