UNL Grazing Corn Residue Research
Many stalks in Nebraska are left ungrazed for various reasons. One reason I’ve heard is the potential impact of increased compaction and reduced yield of the next crop. Nebraska Extension has long-term research addressing this concern…in fact, 16 years of research conducted at the Ag Research and Development Center near Mead. There’s various components to this study and you can view the full report at: http://go.unl.edu/8mp6.
In this study, cattle were allowed to graze corn residue in the spring (February to mid-April) or the fall (November through January) and these treatments were compared to an area not grazed. Corn and soybeans were planted the spring after grazing the residue for 16 years to determine the effect of grazing on the subsequent crop yield.
In the fall grazing treatments, the corn and soybeans were planted no-till. For corn or soybeans planted into the spring grazing treatments, three tillage treatments were also implemented for nine years: no-till, ridge-till, and spring conventional till, after which all treatments were converted to no-till. This result of the tillage by spring grazing treatments for either corn or soybean yield over nine years showed no interaction and suggested the same effect on yield regardless of tillage treatment used after spring grazing.
Spring grazing across all tillage treatments did increase soybean yields statistically (58.5 bu/ac for spring grazed vs. 57.0 bu/ac for ungrazed) and had no effect on corn yields. The results were similar looking at 16 years of grazing vs. not grazing under no-till for both corn and soybeans in the spring; there was no yield effect found for corn and the soybeans showed a slight yield increase with grazing.
Looking at a 10 year period of no-till management for both spring and fall grazed corn residue and subsequent corn and soybean crops, fall grazing statistically improved soybean yields over both spring grazing and no grazing (65.5 bu/ac vs. 63.5 bu/ac and 62.1 bu/ac respectively). No grazing effects were observed on corn yields in either season. All statistics were at the 95% confidence level meaning the researchers were 95% confident any yield differences were due to the treatments themselves vs. random chance.
Regarding compaction, in the fall, the field was typically frozen and the researchers felt any mud and compaction associated with grazing cattle was minimized; highest subsequent soybean yields were achieved with fall grazing. The spring treatment was designed to look more at potential compaction and muddy conditions after spring thaw till right before planting-thus the implementation of different tillage treatments as well. They used a stocking rate consistent with UNL grazing recommendations resulting in removal of half the husks and leaves produced (8 lbs of leaf and husk per bushel of corn grain produced). Results of this study indicate that even with muddy conditions in the spring, grazing increased subsequent soybean yields compared to not grazing regardless of tillage system used and that corn yields were not different between grazing vs. not grazing and regardless of tillage system used in the spring. This study was conducted in Eastern Nebraska in a rainfed environment with yields ranging from 186-253 bu/ac with a 16 year median yield of 203 bu/ac.
Additional Grazing Study
A five year fall grazing study (December through January) was conducted in an irrigated continuous no-till corn field at Brule, NE to determine the effect of corn residue removal via baling corn residue or fall grazing on subsequent corn yields. That environment receives limited rainfall and residue is deemed important for reducing evaporation of soil moisture in addition for catching/keeping snow on fields. Farmers were questioning the effects of any residue removal on subsequent corn yields and the study was implemented.
Treatments were 1) fall grazing at 1 animal unit month/acre (AUM), 2) fall grazing 2 AUM/ac, 3) baled, or 4) ungrazed. The researchers found that residue removal did not affect corn grain yields from 2009-2013 in the continuous corn rotation. There were no statistical yield differences with 5 year average yields of: 152 bu/ac, 155 bu/ac, 147 bu/ac and 148 bu/ac respectively for the above-mentioned treatments.
Forage, Feed, and Grazing Restrictions for Row Crop Herbicides
It’s nice seeing cattle being turned out into corn stalks! One point that I haven’t mentioned recently is that we all need to be checking the herbicide label for any grazing restrictions of crop residues.
So check the labels from in-season applied herbicides to row crops and fall-applied herbicides to crop residue for any potential grazing restrictions…and any restrictions on grazing cover crops planted into crop residues following application of those chemicals to a row crop. If the label doesn’t specify any restrictions, then it should be ok. If you want to be on the safe side, a rule of thumb many chemical reps use is to use the pre-harvest interval for the amount of time to wait before grazing stalks.
Some labels will say that residue should not be grazed or baled and fed to livestock. Sometimes studies were actually conducted to know there is a safety concern. In other cases, the chemical company may not choose to conduct all the studies the Environmental Protection Agency (EPA) required for labeling due to high costs. If that’s the case, the EPA requires the strongest restrictive language be placed on the label.
Regardless, if it says there’s a grazing restriction on the label, the label needs to be followed as it is a legal document and the law. Your cattle may/may not be affected by grazing stalks or cover crops where a chemical with a grazing restriction is on the label, but there may be other concerns such as problems with the chemical affecting the calf or being retained in the cow’s milk.
For quick references, the 2015 UNL Guide for Weed Management shows Forage, Feed, Grazing Restrictions for Row Crop Herbicides on pages 174-177. A new weed guide will be released January 2016. These pages just provide a reference; it’s truly best to read and follow the label.
This week, I’d like to share some information that came out in a white paper from the UNL Agricultural Economics Department on the special relationship we have here in Nebraska between crops, livestock, and biofuel production capacity not found in other parts of the U.S. to the extent we have here. It’s called the “Nebraska Advantage”.
I think it’s important for all of ag industry to realize we need each other as it seems we sometimes forget how inter-dependent we are. Crop producers need the livestock and ethanol industries as they are a high percentage of our end users. Yet many times I hear of crop producers fighting livestock expansion or livestock coming into an area. The purpose of the white paper was to share the numbers of where Nebraska livestock, grain production, and ethanol production currently stands, and what Nebraska could gain if we worked to increase livestock production in-state where we have a wealth of resources with our crops, water, and biofuel production.
Nebraska currently ranks 1st in irrigated acres, 1st in commercial red meat production and is tied with Texas for cattle on feed, 2nd in corn-based ethanol production, 3rd in corn for grain production, 4th in soybean productions, 6th in all hogs and pigs, and 7th in commercial hog slaughter, and 9th in table egg layers. However, in reading this white paper, one quickly realizes we’re not taking advantage of the tremendous grain production capacity here in the State.
We export over 1/3 of our annual corn crop, at least half of the in-state production of distiller’s grains (a co-product from ethanol production that is fed to livestock), and more than 80% of our soybean meal output. Corn and soybean production have increased in our State by 50 and 25% respectively, which is a blessing due to our irrigation capacity. But increasing amounts of this grain are being shipped out-state instead of benefiting rural economies in Nebraska if it was used in-state for value-added livestock production and processing instead.
In the white paper, graphs are shown comparing Nebraska to neighboring states. These graphs show Nebraska lagging neighboring states in growth of the livestock industry. For example, while Nebraska overall increased in hog production, the inventory increased 17.2% during the first half of the decade, but declined 11.8% in the second half. In comparison, Iowa realized an increase of 31.5% within the decade. What was really interesting to me is the fact that Nebraska exports 2.5 million pigs annually to neighboring states to be finished and shipped back to Nebraska for processing, showing potential for growth in the market hog sector. The dairy sector has also declined in herd numbers in Nebraska compared to other states and Nebraska’s poultry industry (mostly egg laying hens) has declined over the past decade in spite of constant numbers across the U.S.
When one looks at Nebraska’s economy, cash receipts from all farm commodities totaled over $25.6 billion in 2012 and livestock/livestock product sales was 45% of this total ($11.6 billion). Increased employment, local tax revenue, value-added activity, and manure for fertilizer are all economic benefits of livestock expansion. The paper stated,
A base expansion scenario that includes a 25% increase in market hogs, a doubling of dairy cow numbers, a ten percent increase in fed cattle production and a tripling of egg production, along with the associated processing industries, has the potential to provide an additional 19,040 jobs, with labor income of almost $800 million and value-added activity of over $1.4 billion. This activity has the potential to generate over $38 million in local tax revenue. While this amounts to a fairly small percentage of Nebraska’s total economy, these impacts will occur almost entirely in non-metropolitan areas of the state and would be quite beneficial to rural economies.
Livestock development has been held back by various issues and policies including: limitations on corporate farming activity in Nebraska, state and local permitting processes, nuisance roles and lawsuits, and issues/concerns from the general public and interest groups. The final conclusion of the paper was that significant growth in employment and economic output throughout Nebraska is dependent upon these issues being overcome.
I would challenge all of us to keep an open mind when producers desire to diversify by including livestock in their operations or through livestock expansion. In many cases, doing so allows another person to come back to an operation, or allows someone to get started farming, which in the long run benefits our rural economies. It’s ok to ask questions, to become more educated. It’s through these questions that one learns how production practices have changed to ensure the health and welfare of our livestock and in odor reduction from the facility and manure application. You can read the entire white paper contents here.
Toothless grins…Fun Fact Friday
Welcome Dr. Lindsay Chichester, UNL Extension Educator, to the blogging world! Here is her first post regarding a “fun fact Friday” on how cattle eat!
Did you know…
Ruminant animals (animals that have one stomach with four compartments and chew their cud; includes cattle, sheep, goats, lamas, etc. – will explain more later) do NOT have teeth on their upper jaw?
Well, technically they have premolars and molars in the very back of their mouths on the upper and lower jaws, but no teeth upper front teeth. Instead they have a dental pad, which would be hard, slick surface.
(Photo: Virginia cooperative Extension)
So how do they eat? Glad you asked! The part of their mouth where the upper teeth would normally be is called a dental pad. When they take a bite of grass they wrap their tongue around it and use the dental pad and their bottom teeth to bite it off.
So how do the young animals nurse you ask… They wrap their tongues around the mother’s teat and use pressure from…
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County Fair Time!
This year marked my 10th Clay County Fair. It was bitter-sweet in a way as I have watched this group of youth from their pre-4-H years through graduation this year. It’s neat seeing the young men and women they’ve become, ready to take that next step in life towards college and careers! Rachel and Kristen, our interns, helped us greatly in different ways which was a blessing; it was another smooth fair overall!
Also bittersweet is the fact that this was Cindy Strasheim’s last Clay County Fair as a UNL Extension Educator as she plans to retire in December. We will miss her and if you see her around, please thank her for her 29 years of dedication to the Clay County Fair and serving our constituents here!
I realize I say this every year, but we wouldn’t have fair if it wasn’t for all of our 4-H and FFA leaders, families, and youth-so thank you all for your hard work and efforts with your projects and the many ways you volunteer at fair! Thank you to our awesome fair board who we greatly enjoy working with and who keep our fairgrounds looking great! Thank you to Deanna, Holli, and Cindy for the long hours of preparation and also during fair in ensuring everything ran smoothly! Thank you to our 4-H Council and all our Superintendents for working so hard in various capacities during fair and throughout the year! Thank you to Tory, Kris, Teri, Karla, and Megan with the Clay County News for sticking out all the shows in the heat to cover the fair for us; we truly appreciate your support! Thank you to Lonnie Stripe for auctioneering, all our auction buyers, plaque and award sponsors, and donors for supporting our 4-H and FFA youth! Thank you to everyone who made the 2013 Clay County Fair a success!
Aflatoxin Concerns in #Corn
This article originally appeared in http://cropwatch.unl.edu written by Dr. Tamra Jackson-Ziems, UNL Extension Plant Pathologist.
Drought and high temperatures promote development of the disease Aspergillus ear rot (pictured right). The fungi that cause this disease (most commonly, Aspergillus flavus) can produce aflatoxin. Aflatoxin is one of many chemicals in a group known as mycotoxins that are produced by fungi (molds). Mycotoxins, such as aflatoxin, can be toxic to animal and human consumers and, at certain concentrations, can lead to dockage or rejection of grain at elevators.The unusually high temperatures and drought this summer are having severe impacts on Nebraska corn. In addition to reductions in test weight and overall yield, secondary problems are developing in some corn fields as a result of these conditions.
Corn harvested for grain to this point has been predominantly from fields that sustained substantial drought damage leading to early maturation and plant death. Notable aflatoxin contamination appears to be in a small percentage of southeast Nebraska fields, based on samples submitted to several laboratories in the area.
Mycotoxins are common and can be safely consumed at low concentrations. The concentration of aflatoxin that is considered safe for consumption depends on the age and species of the consumer. An abbreviated summary listing the Action Levels identified by the FDA for aflatoxin is listed in Table below.
Testing for Aflatoxin: Farmers and crop consultants can scout high risk fields for Aspergillus ear rot as an indicator for aflatoxin, but only lab testing of grain samples can accurately identify the concentrations of aflatoxin in the grain. Accurate lab test results for aflatoxin will depend greatly on the quality of the sample that is collected and the laboratory methods used to test it. The test results are only applicable to the sample that is submitted, so it is very important to collect an adequate sample for the best results. Refer to the publication, Sampling and Analyzing Feed for Fungal (Mold) Toxins (Mycotoxins) for recommendations on how to collect and submit a high quality sample for mycotoxin analysis.
Contact and submit samples to a laboratory that is certified by the federal Grain Inspection Service and Grain Inspection, Packers, and Stockyards Administration (GIPSA) for mycotoxin analysis for the most accurate results. A GIPSA website lists laboratories certified to conduct testing in Nebraska. They include
- Lincoln Inspection Service, Inc.;
- Fremont Grain Inspection Department, Inc.;
- Omaha Grain Inspection Service, Inc; and the
- Sioux City Inspection and Weighing service Company.
Some grain elevators and individuals may be using a black light (ultraviolet light) to detect for fluorescence as a method for rapid screening of grain samples. This practice is NOT recommended when making decisions about aflatoxin contamination in loads of grain. The component that produces fluorescence under black light is called kojic acid. Although kojic acid is produced by the same fungus that produces aflatoxin, its presence is not necessarily an indicator of aflatoxin and might lead to false positive results and unnecessary rejection of grain.
High Risk Factors for Aflatoxin Contamination in Corn
- Drought-damaged fields, including rainfed (dryland) fields and non-irrigated pivot corners
- Fields or areas with higher incidence of corn ear-feeding insects, such as the corn ear worm
- Grain damaged before or during harvest or after harvest while in storage
Ear rot diseases and aflatoxin are not evenly distributed across fields or in the grain, so scouting and/or sampling should include a substantial portion, at least several acres. The presence of the fungus in kernels does not always correlate well with the presence of aflatoxin, nor does the absence of visible fungal growth necessarily indicate the absence of aflatoxin.Scouting For Aspergillus Ear Rot
- Open husks to view a large number of ears.
- Look for the presence of dusty yellow-green to olive-green spores, especially on the surface of damaged kernels or ear tips (Figure above).
- Pay special attention to higher risk areas.
Harvest and Storage: If fields have documented Aspergillus ear rot and/or risk of aflatoxin contamination, it is recommended that you harvest and keep grain separate from other grain at less risk, such as irrigated fields. Storage of affected grain is not recommended because ear rot diseases and mycotoxins can continue to accumulate during storage. If storage is necessary, cooling and drying grain to less than 15% moisture within 48 hours of harvest will help to slow fungal growth and aflatoxin production. Grain intended to be stored for longer periods of time should be dried to less than 13% moisture.
Presently, it is too early in the harvest to know the extent of aflatoxin contamination in this year’s corn crop, but at this time only a small percentage appears to be affected.
Resources: For more information, refer to the list of publications below or view this week’s episode of Market Journal.
- Plant Disease Profiles #3: Ear Rot Diseases and Grain Molds, EC1901
- Understanding Fungal (Mold) Toxins (Mycotoxins), G1513
- Sampling and Analyzing Feed for Fungal (Mold) Toxins (Mycotoxins), G1515
- Use of Feed Contaminated with Fungal (Mold) Toxins (Mycotoxins), G1514
- Aspergillus Ear Rot and Aflatoxin Production, Iowa State University Integrated Crop Management News
- Check Cornfields for Aspergillus Ear Rot, University of Illinois the Bulletin
|Table 1: FDA action levels for aflatoxin contamination in corn intended for livestock.|
|Commodity Action Level||(ppb)|
|Finishing (feedlot) beef cattle||300|
|Finishing swine of 100 pounds or greater||200|
|Breeding beef cattle, breeding swine, or mature poultry||100|
|Immature animals and dairy cattle||20|
|For animal species or uses not otherwise specified, or when the intended use is not known||20|
|Source: FDA Action Levels for Aflatoxin|
Protecting #Nebraska #Ag & #Farm Transition
A few weeks ago I shared some thoughts with you regarding what I learned from an animal welfare conference. We have an opportunity to hear more in at a much closer location-Sutton Community Center in Sutton-on March 12th at 6:00 p.m. Dewey Lienemann, UNL Extension Educator will be presenting on “Protecting Nebraska Agriculture” following a meal sponsored by the Sutton Chamber of Commerce Ag Committee as well as area Cattlemen Associations, Breeders & Feeders, and Ag Producer groups. Anyone interested is invited to attend-and I would encourage anyone who possibly can to attend. This topic not only affects livestock producers, it affects crop producers, and consumers as well. It’s very important to understand how various interest groups are attacking animal agriculture and why and how we in rural America can share our stories. Please pre-register by contacting Tory Duncan at (402) 773-5576 or email@example.com or Todd Mau at (402) 773-5224 or firstname.lastname@example.org.
Another opportunity for learning more about family farm transition is with the last Farmers/Ranchers College program this year. It will be March 15 in Friend at the San Carlos Community Room (next to the Pour House) with meal beginning at 6:00 p.m. (Registration at 5:30 p.m.) The program entitled “Discussing the Undiscussabull” will be presented by Elaine Froese from Manitoba, Canada. Froese’s expertise in helping families get unstuck is sought after across the country. She has worked with families in business for over 20 years and is now coaching the next generation. Elaine believes that change is an opportunity, not a threat…she has practical tools to help people discuss the “undiscussabull” to make their dreams come true. In order to save your spot and reserve a meal, registration is needed by calling the Fillmore County Extension office at (402) 759-3712. The Farmers & Ranchers College is sponsored by area agribusiness, commodity groups in collaboration with the University of Nebraska-Lincoln Extension.