Saturday, April 12, 2014

Evaluate Alfalfa Stands for Winter Injury



                       Rory Lewandowski, Extension Educator Wayne County
            As alfalfa stands break dormancy and begin growth, growers should make plans to take some time to evaluate the health of those stands and determine if there was winter injury.  Some early bud growth was observed the last full week of March in the southern half of Ohio.  This evaluation is especially important in those areas of the state where we had periods of near zero to below zero temperatures this winter combined with little to no snow cover during some of those cold temperatures.   After doing a quick literature review, it appears that there is general agreement that temperatures in the 5 to 15 degree F range as measured at the alfalfa crown can begin to damage the plant and prolonged exposure to these and lower temperatures can kill the plant.  Generally, the soil temperature at a 2 inch depth is associated with the temperature of the alfalfa crown.  Snow cover is an important component of protecting an alfalfa plant from sub-zero temperatures since even a cover of 4 inches of snow can provide 10 to 15 degrees of protection.  Once again, the concern is for those areas that experienced periods of zero and subzero temperatures without a 4 inch or greater snow cover.  For many areas of the state, however, soil temperatures at the 2-inch depth remained at or above 26F even through the coldest days this winter.
            An alfalfa stand health evaluation and winter injury assessment needs to be done by getting out into the field and doing a combination of stand counts and digging up some plant roots.  Generally that evaluation should be done when there is 3 to 4 inches of growth from the plant.  Evaluation involves selecting random sites throughout the field and counting the plants in a one foot square area.  Check at least one site for every 5-10 acres, and like soil sampling, more random sampling is better.  In addition to counting the plants per square foot, a count of the total stems per square foot is also useful because healthy plants can often produce more stems per plant thereby compensating for potential yield loss from fewer plants per square foot.   After counting the plants, dig up all the plants in a one foot square area for every 5 to 10 acres and examine the crown and roots of the plants.
            The winter survival rating determined by the plants per square foot is based upon the age of the stand.  The following table is from a 2012 article on the Iowa State University (ISU) Integrated Crop Management web site by Stephen K. Barnhart, ISU Extension forage specialist.


__________________Plants Per square foot_____________________
Stand Age
Good
Marginal
Consider reseeding
Year after seeding
+12
8-12
Less than 8
2 years
+8
5-6
Less than 5
3 years
+6
4-5
Less than 4
4 years and older
+4
3-4
Less than 3

            As mentioned previously, counting the total stem number in a square foot is another method of evaluating winter survival and yield potential of a stand and has been promoted by Dan Undersander, Extension forage specialist at the University of Wisconsin.  Here is a summary of that system:

Stem number/square foot
Expected result or action
Over 55
Stem density not limiting yield
40-55
Some yield reduction expected
Less than 39
Consider stand replacement
            Source: Undersander et al 2011, University of WI Extension publication A3620

While plant and stem counts are useful, to get a true determination of stand health, plants must be dug up so that crown and root tissue can be evaluated.  To do this you must split the crowns/roots.  The inside should be a creamy white color.  If it is yellowish brown to chocolate brown color the tissue is damaged or dying.  If more than 50% of the roots show these symptoms, reduce your stand counts and yield potential. 
            One other weather condition that can have a detrimental impact on alfalfa stands is freeze/thaw cycles. These cycles that typically occur in February through March often present the greatest danger of winter injury in Ohio. There is the potential during these cycles to physically lift or heave alfalfa plants out of the soil.  This heaving exposes the crown of the alfalfa plant making it more susceptible to temperature and physical injury.  In some cases, heaving breaks the root system, effectively killing the plant.  Heaving tends to be more of a problem in wet, saturated soils and clay soils.
            Although winter temperatures and snow cover amount are primary driving factors affecting alfalfa winter survival, there are also management factors that growers can control to decrease the chance of winter injury.  Those factors include:
·         Selecting varieties with good winter hardiness and disease resistance.
·         Maintaining soil fertility levels.  Potassium in particular is associated with enhancing alfalfa tolerance to winter injury.
·         Improving soil drainage.
·         Harvest management: more cuts is generally associated with a higher risk of winter injury, particularly if the last fall cut falls in that mid-September  to mid-October time frame.

Thursday, January 9, 2014

Forage Production School 2014



A forage production school is being offered by the Ohio State University Extension Dairy Working Group at six locations around Ohio. 
The school is geared to anyone producing hay or silage to be fed to ruminate animals. Dairy, Beef, and sheep producers will be able to improve their forage production to increase profits and commercial hay growers will learn new information to be able to better meet there customer’s needs and grow more tons on less acres.  

The school is composed of three different sessions,  on Jan. 30, Feb. 4 and Feb. 11 from 12:45 pm to 3:30 pm each day
Workshop topics include small grains and double cropping, fertility and manure utilization, agronomic products and additives, precision agricultural technologies for forage production, forage quality evaluation, economics of cutting management, shrink in silage/hay making, forage inventory management and corn silage.
The course will be offered in Ashtabula, Darke, Licking, Mahoning, Morrow, Knox and Wayne counties via interactive video feeds and in-person speakers.
For information on specific class locations contact the following Extension educators:
* Ashtabula County: David Marrison at 440-576-9008 or marrison.2@osu.edu
* Auglaize County: John Smith at 419-739-6580 or smith.132@osu.edu
* Darke County: Sam Custer at 937-548-5215 or custer.2@osu.edu
* Licking County: Ted Wiseman at 740-670-5315 or wiseman.15@osu.edu
* Mahoning County: Eric Barrett at 330-533-5538 or barrett.90@osu.edu
* Morrow County: Jeff McCutcheon at 419-947-1070 or mccutcheon.30@osu.edu
* Wayne County: Rory Lewandowski, 330-264-8722, lewandowski.11@osu.edu 
Registration is $45, which includes a notebook of materials and covers all three workshops.
A brochure about the school and a REGISTRATION FORM can be found at http://go.osu.edu/forageschool.
The deadline to register Jan. 17, 2014.



2014 Ohio Forage & Grassland Council Annual Conference



The 2014 Annual Meeting of the Ohio Forage and Grassland Council (OFGC) is scheduled for February 14 at the Ohio Department of Agriculture located at 8995 E. Main St., Reynoldsburg, Ohio. Registration and refreshments begin at 8:30 am with the program starting at 9:00 am. 
The keynote speaker for this year’s program is Laura Paine, a Grazing and Organic Specialist with the Wisconsin Department of Agriculture. Her two topics are entitled: Managing Pastures for Certified Organic Production and Managing Grazing to Benefit Stream Habitats.
Other speakers on the program include: Dr. Mark Sulc, OSU Forage Specialist, providing a Forage Research Update; Dr. Dave Barker, OSU Forage Specialist on Pasture Management Stategies; Chris Penrose, OSU Extension Ag Educator, speaking on Profitable Forage Utilization.
Producers to be featured on the popular Producer Panel are:
Roger High from Richwood,Ohio on Sheep
Chris Hamn from Racine,Ohio on Dairy
Phil Altsetter from Bellefontaine,Ohio on Beef
Austin Wipple from Orient,Ohio on Commercial Hay Production
There will also be a short business for OFGC and several Forage related Industry Awards presented.
Registration cost is $30 for OFGC members and $50 for non-members and is due Feb. 1, 2014.
For online Registration goto: http://afgc.associationsonline.com/site_event_detail.cfm?pk_association_event=7971
For more information, please contact Gary Wilson at 419-348-3500 or Perry Clutts at 740-248-1448.

Saturday, November 9, 2013

Grazing Corn Residue



Corn Residue: A Resource for Graziers
                        Rory Lewandowski, Extension Educator Wayne County
            For every bushel of corn harvested by the combine, there is between 14 to 16 pounds of corn residue dry matter left in the field.  Graziers need to view that residue as a resource opportunity.  In recent years, between 3.3 to 3.6 million acres of corn have been harvested for grain in Ohio.  The remaining corn residue on those acres is composed of corn grain, cob, husks, leaves, and stalks, all of it with some nutritional value.  Corn residue, when grazed during a mid-October through December time frame is a suitable feedstuff for most classes of ruminant livestock.  The exceptions are livestock in a late gestation or lactation stage of production.  In addition to using a low cost feedstuff, grazing corn residue removes animals from grass pastures during the late fall period.  This can benefit pastures, insuring that they are not overgrazed before they go dormant.  Grazing corn residues can help to stretch stockpiled forages so that they are not used until later in the year.   
            The nutritional value of corn residue varies depending upon how the residue is grazed, the amount of time that has passed between harvest and grazing and environmental conditions.  According to a South Dakota State University Extension publication entitled “Grazing Corn Stalks” a crude protein (CP) content of 8% and a total digestible nutrient (TDN) content of 70% can be expected early in the grazing period.  Over time the nutritional content will decrease to 5% CP and 40% TDN.  This is a typical pattern where livestock are provided with an entire field or a large section of a field and allowed to graze over an extended time period of 30 to 60 days. The nutrient content decreases because livestock are selecting the highest quality, most palatable portions of the residue first and because nutrient content decreases as the residue weathers and soluble nutrients are leached out. 
The University of Nebraska has done a lot of research on the topic of grazing corn residue.  A University of Nebraska study conducted over a 5 year period from 2004 to 2009 measured corn grain left in the field after harvest.  An average of 1.0 bu/acre was available for livestock grazing.  A 2004 Nebraska beef report on corn stalk grazing included more information about the make-up of corn residue.  Generally, stalks account for 49% of the residue dry matter, leaves 27%, husks 12% and cobs another 12% of the residue dry matter.  Livestock typically consume any corn grain first.  After the grain, plant leaves and husks are eaten and the last portions of residue eaten are cobs and stalks. Strip grazing across a field can even out the nutritional quality because livestock will be forced to consume both the higher and lower quality components of the residue within a given grazing period before the fence is moved to provide a new strip.  A 2004 Nebraska beef report on corn stalk grazing listed the average TDN value at 54-55%.
            Now let’s look at an example of how corn residue can be used. The general rule of thumb that is used is; one acre of corn residue will provide grazing for one mature cow for about 45 days.  Often that cow is defined as one animal unit or 1000 lbs.  Most cows are heavier than that so those thumb rule grazing days are less in most instances.  If corn yield is 150 bushels per acre, we might expect somewhere around 2250 lbs. of total dry matter residue.   Not all of that dry matter residue will be consumed.  University of Nebraska research on the effect of stocking rate on animal performance and diet quality while grazing cornstalks demonstrated that very little if any of the corn stalks are eaten.  The study measured the amount of each component of corn residue consumed as a percentage of the total dry matter consumed by cattle.  After corn grain, leaves and husks accounted for 71 to 88% of the total residue consumed and cobs contributed up to another 23%.  Overall the study found that less than one-third of the total residue material available was actually removed from the field.  The University of Nebraska has a corn residue grazing calculator available on-line at: http://beef.unl.edu/learning/cornStalkGrazingCalc.shtml that can calculate the number of acres of corn residue needed for a desired number of grazing days based on corn yield and cow weight.  It will even provide some economic analysis depending upon figures entered into the calculator. 
            Livestock in mid-gestation and even into the third trimester of gestation can do well on corn residue without additional supplementation provided they are not forced to begin eating the actual corn stalks as a significant portion of the diet.  A 2012 Nebraska Beef Cattle Report included the topic of “Supplementing Gestating Beef Cows Grazing Cornstalk Residue”.  This was a 5 year study that evaluated the effects of protein supplementation to beef cows grazing corn residue in late gestation.  The study concluded that “supplementing cows grazing corn stalks in mid to late gestation did not improve cow reproduction or calf performance.  Protein supplementation is not necessary for cows grazing cornstalks, given they begin the grazing period in adequate body condition (BCS greater than or equal to 5).”
            Occasionally I hear some misgivings that livestock can no longer get the same performance from the genetically modified corn residues compared to the non-genetically modified varieties.  This topic has been investigated.  The 2004 Nebraska beef report included results from a study that used steer calves grazing four different fields of corn residue for 60 days. The four fields were residue from a Bt corn rootworm variety, a non Bt variety, a Roundup Ready (RR) variety and a non RR variety.  The conclusion was steer performance was not different between Bt corn or RR hybrids and their non-genetically modified variety controls.  The same study concluded that “there was also no preference between Bt and non Bt hybrids” during the grazing period.
            Some crop farmers may be wary of letting a neighbor’s livestock graze across a field because of concerns about possible negative impact on the yields of subsequent grain crops.  This subject has also been researched at the University of Nebraska in a series of multi-year corn residue grazing studies using various stocking densities.  The conclusion as reported in the 2013 Nebraska Beef Cattle Report was that “…corn grain yields in either a continuous corn or a corn-soybean rotation show no effect of grazing on grain yields and soybeans planted the year following corn residue grazing show a significant increase in yields due to grazing treatment.”
Corn residue represents another opportunity to extend the grazing season. Those graziers willing to find a way to use corn residues by developing relationships with crop farmers, utilizing temporary fencing and water can reduce the amount of stored forage needed for winter feeding and reduce production costs.
University of Nebraska beef cattle reports can be found on-line at: http://beef.unl.edu/web/beef/reports .