After the flames: How fire affects soil nutrients

Hundreds of thousands of acres of forest, rangeland and cropland have sadly gone up in smoke this summer in Montana. In addition to the devastating effect on personal property and direct loss of crops and livestock, fire can affect soil properties and soil nutrients. The impact is highly dependent on the fire intensity/duration and the proportion of plant material that is burned. Timber and shrubs will burn hotter and longer with greater impact on soil than range- or crop land. Fast moving grass fires have minimal impact on soil nutrients and soil health compared to slow moving, intense fires in moderate to heavy fuels.

In general, fires reduce the pool of nutrients stored in organic matter, release a flush of plant available nutrients in the short term, and redistribute nutrients through the soil profile. The availability of nutrients, especially nitrogen, is increased after low intensity fires, yet, a portion of nitrogen and sulfur is lost to the air. Although these losses are not trivial and are similar to removal by harvest and losses to wind erosion, they are small compared to the average pool of nutrients in the top six-inches of soil.

Nitrogen can additionally be lost through nitrate leaching, as the burned plant matter creates a large pool of nitrate and few active plant roots are left to take up either the nitrate or soil water. This can have long term impact on the productivity of forest and rangeland ecosystems, but can be minimized or remediated on croplands. The other nutrients such as phosphorus, potassium, magnesium, zinc and manganese are more stable and not lost directly through combustion, but rather through blowing ash, and post-fire soil erosion.

Cropland fires rarely burn hot enough to affect soil organic matter. The bigger concern is loss of surface plant residue, which is very important to reduce wind erosion, and protect against the physical sealing impact of raindrops. Ash particles also contribute to reduced water infiltration as they plug soil pores. All these factors increase the risk of water runoff and soil erosion.

Intense forest and shrubland fires can burn soil organic matter, reducing the pool of nutrients in the soil, soil aeration and water infiltration/retention, and the soil’s ability to hold nutrients coming from ash or fertilizer.

In addition, forest and shrubland fires can create a water repellent layer within the top 2 inches of soil that comes from compounds in the burnt litter, coating soil aggregates or minerals. The depth and thickness of this layer can vary greatly, and it can affect infiltration for several months to years. This layer should not form on grassland or stubble fires.

Fire kills bacteria and fungi at the soil surface but microbes rapidly recolonize from deeper soil layers, except in severe fires where the soil is sterilized several inches deep. Microbial activity can actually increase with the flush of nutrients available after a fire. However, new input of plant material is important to sustain their populations.

Post-fire management includes soil testing to determine nutrient availability, and establishing ground cover where possible. Test for nitrogen, phosphorus, and potassium to calculate fertilizer needs. Because drought preceded fire, it’s likely that many fields have nitrogen that wasn’t used this summer, so less might be needed next spring. When soil sampling burned fields, be sure to select representative sites, avoid areas where there may have been a windrow, bale, or other high accumulation of straw or residue. Spreading manure can be very beneficial post-fire but this is rarely available or reasonable at large scales.

The MSU Soil Fertility Extension website http://landresources.montana.edu/soilfertility/ has several publications and presentations on soil testing and calculating fertilizer rates. Contact Clain Jones at clainj@montana.edu or 406-994- 6076 if you have any questions.

Bull Breeding Soundness Exams

By Megan Van Emon

Montana State University Extension Beef Cattle Specialist

 

One of the most cost efficient methods of a successful breeding program is the breeding soundness exam (BSE) conducted on bulls.  Bulls are responsible for breeding 20 to 50 cows each breeding season while cows are responsible for one calf each year.  Having a BSE conducted on the bulls is crucial to a successful breeding program.

The BSE is an exam conducted by veterinarians that includes a physical exam, semen evaluation, and an internal and external exam of the reproductive tract.  Evaluating the feet, legs, teeth, eyes, flesh cover, and scrotal circumference and shape is included in the physical exam.  The semen evaluation includes semen normality and motility.  The BSE should be conducted 30 to 60 days prior to the beginning of breeding.  It is important to note that the bull’s sperm production cycle is approximately 60 days, and if illness, injury or other issue occurs, this could negatively impact the BSE and breeding capability of the bull and may need to be re-evaluated.  An additional BSE can be conducted at the end of the breeding season to determine if bull fertility decreased throughout the breeding season.

Body condition is crucial for bulls during the breeding season.  Having adequate flesh cover during the breeding season is needed to provide the extra energy required for breeding.  Body condition can be impacted by the number of cows the bull is expected to breed, the distance traveled to breed or eat, and nutrition during the breeding season.  A body condition score 6 or sufficient body condition that the ribs appear smooth across the bull’s side is the ideal flesh cover at the start of the breeding season.

Ensuring bulls are structurally sound in their feet and legs is needed to begin the breeding season.  Bulls with unsound feet and legs will have a difficult time walking and mounting for mating if a significant distance needs to be traveled for breeding.  General health of the bull is also needed to ensure bulls have adequate semen quality and the ability to mate.  Scrotal circumference is an essential measure because it is directly related to sperm production, sperm normality, and the onset of puberty.  The external and internal reproductive tract examinations ensure there is no inflammation, abscesses, warts, or penile deviations.

The semen evaluation includes the measurement of semen motility or the percentage of sperm cells moving in a forward direction.  The bulls needs to at least have 30% sperm motility to pass the BSE.  Sperm morphology, or the proper shape, is also determined and at least 70% of the sperm cells should have a normal shape.

If all of the minimum requirements are met, the bull will be classed as “satisfactory.”  However, if a bull does not pass one of the tests, they will be classed as “classification deferred.”  If a bull is classed as “classification deferred,” the bull should be tested again after 6 weeks.  If a mature bull fails the subsequent BSEs, they will be classified as “unsatisfactory.”  A young bull may be “classification deferred,” and pass the subsequent test.  Exercise caution when making bull culling decisions based on a single BSE. •

MSU to host annual agricultural research center field days across Montana

The public is invited to attend free annual field days across Montana to tour and learn about the people, places and projects involved with agricultural research at Montana State University’s College of Agriculture and Montana Agricultural Experiment Station or MAES. Five research stations across the state and a local Bozeman campus farm will each host a field day this summer.

“Statewide field days are a longstanding tradition where we invite the public to tour our facilities, meet our faculty and staff and learn about trends and progress in agriculture research that hopefully makes a difference in their lives,” said Barry Jacobsen, associate director of MAES. “What’s most important about field days is that they serve as an opportunity for statewide producers, farmers, ranchers and agribusiness to share successes and challenges face-to-face with faculty scientists and learn about what the university is doing in response to those challenges and needs. It’s a chance for faculty and stakeholders to engage as an agricultural community and for the university to get feedback on what we need to be focusing on.”

Field days include facility tours, explanations of research projects and results and a chance for citizens, producers, legislators and agribusiness representatives to speak with MSU scientists and Extension agents.

Summer 2017 field days include:

  • Northern Agricultural Research Center, Thursday, June 29: The field day begins at 4 p.m. with tours before and after dinner. The center is located about seven miles southwest of Havre on U.S. Highway 87. (406) 265-6115.
  • The MSU Arthur H. Post Agronomy Farm , Thursday, July 7: The Post Farm will begin tours at 8:30 a.m. followed by lunch. The Post Farm is located eight miles west of Bozeman on U.S. Highway 191. (406) 586-6819.
  • Central Agricultural Research Center, Wednesday, July 12: The field day starts at 9 a.m. and includes a free lunch. The center is located 2.5 miles west of Moccasin on U.S. Highway 87. (406) 423-5421.
  • Northwestern Agricultural Research Center, Thursday, July 13: The field day begins at 2 p.m., with dinner following the tour. NWARC is located near Creston on State Highway 35. (406) 755-4303.
  • Eastern Agricultural Research Center, Wednesday, July 19: The field day begins at 9 a.m. The center is located one mile north of Sidney on State Highway 200. (406) 433-2208.
  • Western Agricultural Research Center, Thursday, July 27: The field day starts at 4 p.m. with dinner at 5 p.m. and a tour following. WARC is located at 580 Quast Lane, Corvallis. (406) 961-3025.

MAES comprises agricultural research of on and off-campus MSU faculty. The research centers are strategically located across Montana to allow research with different soil types, elevations, climate zones and landscapes, and a local advisory council guides the research at each station. The federal Hatch Act of 1887 authorized every national land-grant university to establish an agricultural experiment station, with research reflecting the university’s curriculum and state needs. The Smith-Lever Act authorized the Extension Service in 1914. MSU College of Agriculture, Montana Agricultural Experiment Station and MSU Extension have been cooperatively serving the land-grant mission and the Montana public for the past 100 years.

For more information about the Montana Agricultural Experiment Station, visit http://agresearch.montana.edu/maes.html. For more information about the station’s research centers, visit http://agresearch.montana.edu/researchcenters.html.

MSU Extension sets March 10 workshop on agricultural resiliency

BOZEMAN – Montana State University Extension in Gallatin County will host the workshop “Building Resiliency in Agriculture,” from 10 a.m. to 3 p.m. Friday, March 10, at the Gallatin County Extension office, located at 903 N. Black Ave., Bozeman.

The workshop aims to improve farmers’ and ranchers’ ability to respond to variability and extremes in agricultural operations. Topics will include past, present and future climate; flexible stocking rates; emerging crops; weed management; irrigation efficiency and soil moisture measurement; and financial resiliency.

To register, contact Emily Lockard, MSU Extension agriculture agent, or Brad Bauer, MSU Extension natural resources agent, at (406) 582-3280, gallatin@montana.edu. Attendees can also register at the Extension office in Bozeman. The workshop costs $10 and includes lunch.

For more information, see: http://www.gallatinextension.com.

MSU Extension and MSGA announce 2016 Steer of Merit certifications

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Montana State University Extension and the Montana Stockgrowers Association (MSGA) distinguished 106 “Steers of Merit” out of 924 entries for 2016. Out of 612 steers entered in the Carcass Division, 69 were deemed Steers of Merit. In the Ultrasound Division, 37 out of 311 entries received the distinction.

 

The exhibitors and breeders of the top five steers in each category were honored at MSGA’s Annual Convention, Dec. 7-9 in Billings at the Radisson Billings Hotel. The top five steer entries in the Carcass Division were: 1) Kaleb Probst, Beaverhead County (Probst Livestock, breeder); 2) Reese Meine, Beaverhead County (Reese Meine, breeder); 3) Layne Boeh, Park County (Terry Reuter, breeder); 4) Sara Malesich, Beaverhead County (Malesich Ranch, breeder); and 5) Madeline Hamilton, Missoula County (Two Creek Ranch, breeder).

 

The top five steer entries in the Ultrasound Division were: 1) Brighton Lane, Montana Fair (Dr. Bryan Roe, breeder); 2) Tucker Turbiville, Fallon County (Tucker Turbiville, breeder); 3) Beau Bromenshenk, Montana Fair (Bromenshenk Farms, breeder); 4) Tate Thompson, Montana Fair (breeder unknown); and 5) Isabelle Lowry, Montana Fair (Probst Livestock, breeder).

 

The number of Steer of Merit certifications for 2016 decreased by 2 steers, with 21 more entries submitted compared to 2015.

 

The Montana Steer of Merit program was initiated in 1967 as a joint effort between the Montana Stockgrowers Association and Montana State University Extension. The program was designed to measure, record, and improve carcass characteristics in beef cattle. Data from these carcasses has been summarized and analyzed statistically. Over time, significant increases have been made in quality grade and in yield grade, or cutability, indicating that cattle can be selected for leaner carcasses with higher cutability and still maintain high quality grade as reflected by marbling.
To be designated a Steer of Merit, carcasses are evaluated by a qualified individual using information that relates to yield of lean meat and eating quality. Beef carcasses must meet criteria set by the Steer of Merit Committee in the areas of hot carcass weight, dressing percent, fat thickness over 12th rib (back fat), total rib eye area, yield grade, percent cutability, and quality grade. Computer software programs help compile data and rank carcasses for state and county awards. Data is also analyzed periodically to track genetic and feed management progress. The minimum standards for Steer of Merit are reviewed each year and the program is updated to meet the changing industry standards.

 

For more information about the Steer of Merit program call Megan Van Emon, Montana State Extension Beef Cattle Specialist at (406) 874-8286.