Minnesota Crop News

Hybrid Maturity Considerations for Delayed Corn Planting

2013-05-17T18:23:00Z

By Jeff Coulter, Extension Corn Agronomist

For much of Minnesota, the windows of opportunity for corn planting have been late to arrive and interrupted by weather. This article addresses several concerns about late-planted corn.

Expected yield remains high for corn planted by May 25

University of Minnesota Extension planting date studies show that highest corn yields typically occur when corn is planted by early to mid-May. However, high corn yields can still occur if planting is completed prior to Memorial Day.

In a study from 2009 to 2011 at Lamberton, Morris, and Waseca that was funded by the Minnesota Corn Growers Association, grain yield was still within 93% of the maximum if planting was completed by May 25. In another study from 1988 to 2003 at Lamberton, a planting date of May 25 resulted in grain yields that were 87% of the maximum. With this year's late spring, yield reductions due to delayed planting will likely be similar or less than those observed in the study conducted from 2009 to 2011.

Avoid planting when soils are too wet

Although it is important to finish corn planting as soon as possible now, it is equally important to avoid planting when soils are too wet. Sidewall smearing can occur when double-disc openers cut through wet soil, resulting in compacted soil around the seed that is difficult for nodal roots to penetrate. Seed furrows can also open up after fine-textured soil dries following wet conditions at planting, resulting in poor seed-to-soil contact and poor stand establishment.

Stick with planned hybrids a little longer

In order to maximize economic return, a general guideline for growers in Minnesota is to stick with the planned seed choices until May 25. This is supported by a University of Minnesota Extension study conducted at Lamberton and Waseca in 2010 to 2012 that was funded by the Minnesota Corn Growers Association and is shown in the figures below. In this study, highest grain yield occurred with mid- to full-season hybrids (99- and 104-day relative maturity), even when the average planting date was as late as May 24. However, grain moisture at harvest was 2.3 percentage points higher with the 104-day hybrid than the 99-day hybrid with the late planting date (May 24).

When corn planting occurs between May 25 and May 31, it is wise to use hybrids that are 5 to 7 relative maturity units earlier than full season for the region. This reduces the risk of the corn being frozen prior to physiological maturity in early autumn.

Planting grain corn after May 31 carries high risk in Minnesota. If corn must be planted after May 31 in Minnesota, growers can reduce their risk by planting hybrids that are about 15 or more relative maturity units earlier than full-season hybrids.

At June 5 or later, most growers in Minnesota that still need to plant should consider planting a crop other than grain corn if feasible. However, the decision of what to plant is also influenced by factors such as fertilizer applied and seed availability. These factors will need to be evaluated on a field by field basis.

Additional information

Corn production: http://z.umn.edu/corn

Late planting: http://z.umn.edu/lateplanting

University of Minnesota Extension Launches Websites for Alfafa Weather Damage and Survey to Determine Extent of Alfalfa Damage

2013-05-16T03:46:13Z

By David Nicolai and Doug Holen, Extension Educators - Crops

The University of Minnesota Extension Forage Team has developed a list of resources available to livestock and alfalfa producers affected by the recent alfalfa winter injury and winterkill in 2013. These resources are available at the U of MN Extension crops website http://www1.extension.umn.edu/agriculture/crops/spring-issues/

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Reports of winter injury and winterkill of alfalfa continue to intensify across parts of southern Minnesota. Producers are examining options in light of their field assessment and inventory; many are faced with purchasing hay or growing some type of emergency forage crop. Livestock producers will need to carefully consider short and long-term inventory needs and then manage the damaged alfalfa to get as much tonnage and quality as possible. The University of Minnesota Winter Injury article for livestock producers which is located on-line at the U of MN extension crops web site includes information on Forage Inventory Management, Feeding , Animal and Forage Cropping Options.

The University of Minnesota and Wisconsin Forage Teams are collaboratively working to better understand the scope, severity and causes of this year's alfalfa winter injury that has been reported throughout the two states

We are asking all Minnesota and Wisconsin alfalfa and hay producers to complete a brief 12 question survey before Friday, June 13, 2013. Please answer all questions, and then select "Done" and your answers will be recorded. The survey can be found at https://www.surveymonkey.com/s/alfalfainjury2013. One survey per farm is sufficient. (individual survey results are confidential and only bulk represented by county and state.)

We will share the summarized survey results at future Minnesota and Wisconsin forage programs.

In addition to the forage producer survey we have developed a specific alfalfa winter injury survey for crop consultants and ag professionals to better understand the scope, severity and causes of this year's alfalfa winter injury that has been reported throughout Minnesota from their unique perspective as consultants to forage producers available at https://www.surveymonkey.com/s/2013alfalfainjuryconsultant

Again this consultant survey will help researchers and extension personnel to better understand this year's alfalfa winter injury that has been reported throughout Minnesota thus helping with future recommendations for similar winter injury events. Thank-You.

Sauk Centre Hay Auction Report May 2, 2013

2013-05-10T22:11:30Z

by Dan Martens, U of M Extension Educator in Stearns-Benton-Morrison Counties

Three Items:

1. Reports from May 2, 2013 Sauk Centre Hay Auction (here)

2. Winter Alfalfa Injury Resources (read more)

3. Alfalfa Harvest Alert Scissors Cut Project in Central MN (read more)

MAY 2 HAY AUCTION REPORTS

May 2 2013 SC Hay Auction.pdf ... A summary of all tested hay lots and bedding materials sold... grouped by kind of hay, type of bale and 25 RFV points... cost per pound of dry matter and per RFV point are calculated.

History of Selected Lots 2012 2013.pdf ... A summary of hay auctions held this year showing Medium Square Alfalfa 101-200 RFV divided in 25 RFV groups, and medium sq. straw.

Graph 2001 to 2013 SC Hay Auction.pdf ... A line graph of these auctions from 2001 to 2013. For the Feb 16 auction, the 176-200 RFV group is just one load - so not really an average.

The next auction at Sauk Centre will be held on Thursday May 16.

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Extension Staff, farmers and agribusiness people have been busy for the last 10 days or so evaluating fields and sorting out information together that might be useful in dealing with significant winter injury to alfalfa. At this time it looks like the most serious issues are across southern MN and southern Wisconsin.

There are some problems through central Minnesota also, but generally not as widespread and not as intense. But if you have a lot of it on your own farm, it is significant.

We have posted some articles that might be useful on the Extension Agriculture Crops Web page. Go to

http://www1.extension.umn.edu/agriculture/crops/

Look for "Spring 2013 Issues" in the upper right-hand corner.

The most recent article is an overview of alfalfa evaluation, crop strategies, livestock strategies.Other articles provide more detail about some topics. More may be added during the coming week.

A more direct link might be (http://www1.extension.umn.edu/agriculture/crops/spring-issues/).

I believe Jim Salfer is summarizing some of this for an article in the next DairyStar.

Because Wisconsin is dealing with a lot of this too, The Wisconsin Extension Forage website is a good source for a lot of practical information related alternative forage crops and related issues.

www.uwex.edu/ces/crops/uwforage/uwforage.htm

You can also do a search for "Minnesota Crop News" to catch information and links.

blog.lib.umn.edu/efans/cropnews

THIS IS A GREAT PLACE TO PICK UP CURRENT INFORMATION AS THE CROP SEASON UNFOLDS WITH A VARIETY OF CROP ISSUES.

SURVEY - Some Extension staff are working on a web based survey to see what we can learn from this experience this year - any key factors and trends related to alfalfa and grass hay or pasture problems. So some of you might watch for that.

ALALFA HARVEST ALERT SCISSORS CUT PROJECT - CENTRAL MN

We will be working with the Central MN Forage Council and cooperating farmers and agribusinesses again this year. I doubt if we will take our first samples before May 20, unless things take off in an unusual way. I am attaching a new release about or plans for this year based on arrangement that are confirmed so far. Please let me know if you have any question or suggestions about this.

2008 was a really slow spring. We took our first samples on May 22 with alfalfa 14 to 16 inches tall. The main harvest push from June 2 to 9. Rain showers scattered through the last week of May and first 10 days of June and made harvest decisions more challenging.

Alfalfa Harvest Alert Project.pdf

Let's encourage each other to work safely and patiently along with persistently and strategically. Let's think about that with family and working relationships as well as with the work. I'm still learning that too.

Starter and Sulfur Fertilizer use for Corn:Spring 2013

2013-05-10T16:42:13Z

By Daniel Kaiser

Extension Soil Fertility Specialist

With the variation in conditions we have seen this spring there are a few issues that may show up in fields related to cool and wet soils. Purpling of corn leaves due to phosphorus (P) deficiency and early season interveinal striping due to sulfur (S) may occur if temperatures remain cool and we continue to have frequent rains. I want to take some time and outline these issues and some of the related research that has been conducted in the past five years.

]]> Starter Fertilizer Use and Purple Corn

I have had a few questions related to starter fertilizer use this spring. With planting being delayed there may be some questions as to what can be eliminated from the planting operation to speed things up. If we continue to see the temperature changes that have occurred thus far I would except to see some purpling on corn that has already been planted as it is coming out of the ground. Whether this purpling actually affects yields is debatable.

We typically say that starter helps get corn out of the ground in cool and wet soils we typically see in the spring. Survey work on research data from Wisconsin by Dr. Larry Bundy indicated that the potential for a significant return to starter was greater with later planting dates with full season hybrids. So the questions on forgoing the starter fertilizer are valid as we progress into what should be warmer planting days. However, the Wisconsin data gives an alternate prospective that may indicate that some starter still should be used.

In a joint project between Jeff Coulter and Myself we studied the effects of starter fertilizer use on medium to high P testing soils for three differing hybrid relative maturities (94, 99, and 104 day) at three different planting dates over three years at the Southern and Southwest Research and Outreach Centers at Waseca and Lamberton. The main conclusions that can be drawn from the data is that 5 gallons of 10-34-0 applied "pop-up" consistently increased plant height early in the growing season and sped up the time to silking by 1-2 days across hybrids and planting dates. However, we found very inconstant yield responses. In most of our studies we have been seeing that if broadcast P is applied the starter P has less of an impact on yield. The exception to this may be high pH soils, but many our responses have been similar to more acid soils with high P availabilities.

Certain years seem to favor responses to starter regardless of broadcast P applied or high testing soils. One option is to reduce the rate applied for those whom wish to still apply some starter. In most of our studies we have seen little difference between 2.5 and 5 gallons of 10-34-0 per acre. Reduced rates would allow coverage of more areas per fill of the planter and is a viable solution for those not wanting to eliminate "pop-up" in their fertilizer program. An application of 2.5 to 3.0 gallons per acre still can give a satisfactory growth response and will likely give a similar yield increase if we occur a year where there is a high probability of a response to starter.

Striping on Corn Leaves due to Sulfur

As we have become more aware of sulfur deficiencies the instances of early season striping on the upper corn leaves have seemingly increased. With the spring we have had at this point I would expect some lower mineralization rates and potentially some striping to occur. I have seen this happen in some of our studies even when sulfur is applied so the overall effect on yield should be small unless the issue is present through the fifth leaf stage (about 12" tall). We have seen little difference when corn yields respond to sulfur when the fertilizer is applied at plating or by the fifth leaf stage. As long as there is a source of sulfur at that point yields should not be limited. If mineralization begins by that point sulfur may not need to be applied.
Watch fields applied with elemental sulfur in the fall closely. With the cool temperatures there may be some fields that may show yellowing because of poor conversion of elemental sulfur to sulfate. Some recent data we have collected shows that our soils have a capacity to mineralize elemental sulfur fairly rapidly at high soil temperatures. But the process still takes time and with the cool conditions we have seen the conversion will be very limited.

If a deficiency is detected sulfur can be applied early in the season. Remember that broadcast AMS does pose some risk for damaging corn leaves if the fertilizer gets into the whorl. Normally at low rates of S this damage should not result in a large reduction in yields. Gypsum and potassium sulfate could be used as substitutes. Ammonium thiosulfate liquid could be used, but not as a sprayed on application over the top of the plants as significant leaf damage may occur. ATS is best suited for surface dribbled or knifed in applications for corn to avoid tissue damage.

Iron Deficiency Chlorosis Research in NW Minnesota

2013-05-09T14:32:04Z

By John Wiersma
Agronomist
Northwest Research and Outreach Center

High pH, highly calcareous soils, common in western Minnesota, restrict the availability of soil Fe needed for optimum soybean growth and yield. On such soils, the amount of Fe fertilizer applied must surpass a threshold before there is sufficient available Fe in the soil solution to induce a positive growth response. Only a limited number of management tactics designed to improve the availability of Fe have been studied with soybean. These include variety selection, seeding density, seed-applied or in-furrow materials, and foliar treatments.

]]> John Wiersma outlining research findings conducted over many years in the Red River Valley. Click on the link to the PDF file to read more.

Fe Chelates_Wiersma.pdf

Maximizing forage in winter injured and killed stands, Spring 2013

2013-05-03T18:32:19Z

By Dr. Craig Sheaffer, David Nicolai and Doug Holen

An unusual amount of winter injury and winterkill of alfalfa stands occurred in south central and southern Minnesota. While reports do not represent a detailed analysis of where injury to alfalfa has occurred across Minnesota, they do suggest a need for producers to check on stands and evaluate them for potential winter injury.

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Several environmental factors likely interacted to stress alfalfa and cause winter damage. These include: 1) a very dry fall and early winter that may have prevented alfalfa from accumulating adequate root reserves to survive the unusually long dormant period; 2) periods during the winter without snow cover which typically provides insulation against low air temperatures; 3) ice sheeting due to snow melting and rainfall in January/February; and 4) the long periods of snow cover and low temperature that prevented spring alfalfa regrowth when reserves were low.

What does winter injury look like?

Slow or no "green up" in all or portions of the field. It is intuitive that if plants are dead, there will be no regrowth. There may be regions of the field that are green while other areas remain brown. Alfalfa is a perennial that hibernates during the winter. In the fall, energy reserves are stored in the roots and crown buds are formed. The reserves provide energy during the winter and in the spring shoots grow from the crown buds. Injury can destroy the roots and crowns but often some crown buds survive and slowly regrow; however, this may be limited to only a few per plant and these may be stunted or chlorotic (yellow).

Alfalfa taproot on the left is turgid from a live and healthy plant. The alfalfa taproots on the right are brown, dehydrated and ropey from dead or dying plants. Photo courtesy of Dr. Dan Undersander, University of Wisconsin.

Uneven regrowth. Damage to several of the crown buds during the winter will create uneven regrowth. The plant has potential to regenerate new crown buds, but this regrowth is typically delayed. Plants look "scraggly." If the plant root has been damaged, some shoots may die.

Root damage. Healthy roots are firm and white. Injured roots are spongy, grey, and if twisted, water can be expressed. Over time, injured roots will become diseased, rot and turn dark brown. A damaged root cannot sustain crown bud growth.

We recommend the following:

1) First make sure that "dead" spots are actually dead and not just delayed: (Stands can be slow to recover when injured). So don't be in too much of a hurry to till up a stand until you've looked at some roots to determine health)

a) Dig up a few plants and check the top four inches of the tap root for color and turgor. Split the root and crown. The tap root should be an off white (like the inside of a potato) and turgid (not ropey).

b) Check plants that are putting out small shoots. Sometimes the dying plants will produce shoots one to two inches tall and then die. Again, dig a few plants and look for off‐white and turgid taproots. Regrowth should also be scouted following first cutting as sometimes plants have the ability to put on growth initially but die after being harvested.

2) Determine the percentage of field affected and manage to meet your goals, there are several alternatives approaches:

a) If a small or moderate percentage of the field is affected and you want to harvest forage from the existing stand, go over the affected areas with a drill seeding (10 lb/a) with a 50/50 mix of Italian (annual) ryegrass and perennial ryegrass to a maximum depth of ¼ to ½ inch.

b) If a moderate percentage of the field is affected you can immediately interseed Italian ryegrass (10 lb/a), take the first cutting for forage. Corn or soybean can then be planted into the killed forage. An alternative to this approach is to take two forage harvests and seed oats for fall forage.

c) If a moderate or large amount of the field is affected seed oats (2 bu/a) and peas (20 lb/a) for haylage harvest. In some regions, corn or sorghum-sudangrass can be planted following the oat-pea harvest.

d) If a large percentage of the field is affected, seed corn or BMR sorghum‐sudangrass before July 1 (20 lb/a). These crops can use the nitrogen from alfalfa. Corn will likely produce the most tonnage of any forage. Sorghum‐sudangrass is a good choice if you expect dry conditions and/or above average temperatures (like last year). Alfalfa can be seeded into a different field at 10 to 12 lb/a either alone or in mixture with grass (e.g., 6 lb/a tall fescue and 2 lb/a Italian (annual) ryegrass).

e) Once a stand of alfalfa is killed from a winterkill event, auto-toxic compounds are released into the soil environment. How long they remain and what affect they have on a new alfalfa seeding is a function of soil type, temperature, amount of rainfall, and time from tillage to reseeding. Directly reseeding is risky, but the minimum risk of autoxicity occurs if you till the old stand and incorporate the residue, wait 1 month from tillage to reseeding, and the old stand is one year old. Risk is also less on sandy soils. The University of Minnesota Agronomy department has developed an alfalfa autotoxicity risk spreadsheet (http://z.umn.edu/AlfalfaAutotoxicityRisk) to help growers determine the risk of re-seeding alfalfa in existing alfalfa stands along with appropriate management recommendations.

In situations where producers are making decisions for the long term they should use stem counts to estimate current yield potential and assess root and crown health to determine future yield potential. Stand health based on stem densities per square foot can be assessed in the following manner:

· Greater than 55 stems indicates density will not be a limiting factor,

· Between 40 and 55 stems is understood to represent some reduction in yield but probably more than adequate in years of low inventories and high value, and

· Fewer than 40 stems indicate a poor stand and consideration for termination.

Stands can be slow to recover when injured. So don't be in too much of a hurry to tear it up until you've looked at some roots to determine health. If surviving plants are injured, but have adequate stem density to maintain the stand it's probably best to plan to push the stand with annual forages (i.e. Italian ryegrass or oats) to get the most out of it this year than to plan to terminate after this growing season. If most surviving plants look reasonably healthy (i.e. losses were localized and/or ice-sheeting related) you might consider inter-seeding perennials to stretch the stand beyond this year. Note that legume credits from winterkilled alfalfa fields are the same as if the stand had been terminated last fall. Article contributions: Dr. Dan Undersander, Department of Agronomy, University of Wisconsin

Daniel Kaiser
439 Borlaug Hall
1991 Upper Buford Circle
Saint Paul, MN 55108
612-624-3482
dekaiser@umn.edu

Soil Testing Sentinel Program in Minnesota

2013-04-29T15:08:55Z

By Daniel Kaiser

University Extension Soil Fertility Specialist

With the extreme variability in growing conditions there have been some questions regarding the variability in soil test. A project is being launched to establish a series of sentinel plots to study the monthly variation in soil test values over the next two growing season. We are looking for participants that are willing to take samples from a single point within a field and mail them off to us at Saint Paul. The goal of this study is to gain a better understanding of what is happening over the growing season for a number of different nutrients commonly measured.

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1) Select and geo-reference a field area with GPS in order to return to that site every 4 to 6 weeks when sampling is possible.
2) Collect about 2 lbs of soil in a fixed area around the sampling point. Within a radius of 10 feet or less would be adequate.
3) Label the sample with location and sampling date and store in a lined or Ziploc bag and place in a refrigerator.
4) Send the samples off to the University.
5) If possible, hand harvest a small section around the sampling point.

Maintaining the samples in a cool place where the loss of moisture is critical. Once we receive the samples they will be sieved and split into two samples, one will be air dried and sent off for analysis. The second sample will be kept in a field moist state for analysis, One major component of this work will be to attempt to gain a better understanding of the variation of the potassium soil test over time. The moist samples will help to determine if the difference between the field moist and dry potassium test warrants more research around the state of Minnesota.

Postage to send the samples off to me is available, or a pickup can be scheduled. Compensation for travel to and from the sampling sites can be arranged.

We also will have soil temperature sensors to install at the field locations. Soil moisture will also be measured, but completed directly from the soil samples by taking weights before and after drying. Moisture and temperature will be studied in order to determine if there is any link between differences in analysis before and after drying on the test themselves and on the variability in the soil test over time.

If interested, Please contact Daniel Kaiser via email (dekaiser@umn.edu) or by phone at
612-624-3482. We currently are looking for up to 20 sampling locations to start by the end of 2013 to represent most of the major soil associations around the state of Minnesota..

Specific details for the project can be found in the link below.

Soil Test Sentinel Plots.pdf

Black cutworm pheromone trapping network

2013-04-26T15:54:10Z

By Bruce Potter

IPM Specialist SW MN

The late spring has had one advantage. Migration of insect pests from the south into Minnesota has been delayed.

The black cutworm, one of the migrant pest species that sporadically causes problems in Minnesota crops, reduced stands in some 2011 and 2012 corn fields. The females prefer to lay eggs in un-worked fields where areas of winter annual or early spring germinating weeds, common lambsquarters for example, occur.

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This spring, 70 intrepid cooperators across southern MN are manning pheromone traps to detect black cutworm moths migrating into Minnesota. Based on when and where moths are captured, potential damage can be predicted. We will provide alerts if any significant moth flights are observed this spring. We cannot predict damage from other cutworm species that overwinter here.

To this point in the 2013 spring, weather systems have not been favorable for migration and very few moths have been captured. This could change with the next thunderstorm. Depending on how soon they arrive, immigrating black cutworms could find plenty of locations to lay eggs because of the delay in spring tillage.

This spring, you can view black cutworm trap captures and a weekly report at: http://swroc.cfans.umn.edu/ResearchandOutreach/PestManagement/CutwormNetwork/index.htm.

Does My Soybean Crop Need Sulfur?

2013-04-26T15:38:35Z

Daniel Kaiser
Extension Soil Fertility Specialist

I know there are still questions on the application of sulfur for soybean. Between me and a number of other researchers in Minnesota, we have been working on a number of projects focusing on sulfur management on corn, soybean, and spring wheat. Recently the soybean research has been fully summarized so I want to take a minute or two to highlight some of the findings to outline where we are at with the current guidelines for fertilizer management on soybean.]]>
We have been mainly focused on researching sulfur response for corn. One thing that seems to come to the forefront in this research is the overall importance of soil organic matter when considering where a yield increase will occur. For soybean it is not that simple. If you go through much of the research from around the country there is not much supporting evidence for recommendations for sulfur application to soybean. I believe much of any potential for response of soybean to sulfur is related to a few factors, the most important of which revolved around climatic conditions. Where we saw the response was in 2009 which was a year that saw very large responses to sulfur in many of our corn studies. With temperatures being cool and with most areas being relatively dry the potential for mineralization of sulfur from organic matter was low. Two other factors I think were important at the locations were the soil and the previous history of sulfur deficiency symptoms in other crops (alfalfa and corn). The site was on a silt loam soil in southeastern Minnesota with an organic matter concentration that averaged less than 2.0% in the top six inches. All these factors together created a perfect storm in terms of creating conditions were a sulfur application would benefit soybean.

Other than the field location in 2009, there was one other instance that I know of where sulfur benefitted soybean at the Southwest Research and Outreach Center at Lamberton. In this instance soybean yielded higher with sulfur, but the sulfur was applied before the previous corn crop. To follow up on this response we set up trials to look further into the sulfur cycling within corn-soybean rotations to better understand if there are greater benefits from application before the corn crop. One thing that we found in the studies in 2008 and 2009 is that we increased the amount of soybean plant material relative to the total grain produced, meaning we had more plant material per acre. When sulfur and phosphorus were added with N there was a large increase in soybean vegetative growth at all locations. This concerns me due to extra water usage in dry years and potential for disease pressure to increase.

So what are the overall benefits? Increased yield is the overall goal but I do not think that there is a widespread need for sulfur to be applied on all soybean acres. I think the best bet would be to look at fields that are in a areas prone to sulfur deficiency on corn or alfalfa, soil organic matter is around 2.0% or less, and the field has not had any sulfur (including manure) applied to it for several years. In this case 10-15 lbs of sulfur broadcast per acre should be enough for soybean. I would suggest not applying high rates of nitrogen and phosphorus with sulfur. In our field trials we broadcast potassium sulfate and did not see the large increases in plant mass. Another source that may work is gypsum.

I do not think sulfur needs to be applied to soybean if it was applied the previous year. Based on all of the data we have there does appear to be enough sulfur cycling from year to year that the soybeans crop should have enough. Sulfur does leach out of the soil but the relative rate it will leach is lower than some other anions. In coarse sand our data indicates that given enough rainfall any sulfate applied will be below the 2 foot depth in the soil by the middle of the growing season. Even with a small increase in clay content that rate can be reduced. At another site with a loam soil texture we just started to see elevated levels of sulfate by the end of the growing season. Thus, there will likely be some sulfate still in the profile for the soybean crop as long as rainfall is not too excessive.

The other aspect we have been studying is sulfur cycling in corn residue. Based on the information I had a few months ago there did not appear to be much, if any, sulfur that would mineralize from the breakdown of corn stover. However, a more recent set of data shows that it may be possible. From the data we have now, without sulfur, the ratio of carbon to sulfur tends to maintain at a point where the breakdown of corn stalks will not release or tie up sulfur. However, when we looked at the data from 10 and 20 lbs of sulfur applied to corn, the ratio became smaller indicating a potential for a small amount of sulfur to be potentially released. The amount released will again depend on soil temperature, moisture, and tillage to incorporate the residue. This cycling mechanism may explain some of the response we saw in 2009. We also studied higher rates, but the effect appeared to not extend past 20 lbs of sulfur.

To reiterate, if sulfur is applied before another crop I do not think it needs to be applied before soybean, especially corn where the chance of a profitable return is much greater. I think yield can still be increased without a direct application and we also have evidence to increases in grain protein concentration when sulfur was applied before corn. These increases have only been identified in our work in Southeastern Minnesota at this time. While most of our evidence does not support widespread use of sulfur on soybean, some of the isolated responses indicated that some changes needed to be made to our recommendations. Moving forward we will continue to study the cycling mechanisms in order to provide the most up to date information for our current guidelines.

Fertilizing Soybean in Minnesota

Safely Handling Treated Seed

2013-04-25T15:12:14Z

By Lizabeth Stahl, Extension Educator - Crops

Much of the seed planted this year will have been treated with a fungicide, insecticide and/or nematicide. As when working with any pesticide, care should be taken when handling treated seed so that exposure to the handler, non-target organisms, and the environment is reduced or prevented as much as possible.

]]> Exposure to the Handler: Although growers may be more familiar with checking an herbicide or insecticide label for the appropriate personal protective equipment (PPE) to wear when handling a product, every bag of treated seed will also list the proper PPE to be worn when handling the treated seed. Wearing the appropriate PPE will help reduce or prevent pesticide exposure when working with treated seed.

The PPE to be worn when handling treated seed will typically include a long-sleeve shirt, long pants, shoes, socks, and chemical-resistant gloves. Unless the seed bag label specifies the type of chemical-resistant gloves to be worn, there are several types a handler can choose from, varying in flexibility and durability. Note that leather or cloth gloves are not chemically resistant! Cloth and leather gloves can soak up pesticide residues and result in pesticide exposure each time they are worn.

Handlers of treated seed should also take care to limit exposure to any dust when opening or emptying out seed bags.

Exposure to non-target organisms and the environment: Treated seed is not to be used for food, feed or oil processing, and care must be taken to not contaminate grain that will be going into the food or feed market. There is ZERO tolerance for treated seed in the export market, meaning that a single seed could result in the rejection of an entire load.

Treated seed should also not be left on the ground surface as some products can be hazardous to birds and mammals, or may be toxic to fish and aquatic invertebrates. Any seed spills should be covered or cleaned up as soon as possible.

A number of products are also toxic to bees and pollinators, so care should be taken to minimize dust as much as possible when filling and emptying out planters. Avoid conducting these tasks near flowering plants where bees and pollinators may be foraging.

Disposal of leftover treated seed: The best and most preferred option is to plant out any leftover treated seed on fallow ground or an unused parcel of land. Depending on the seed treatment, there may be restrictions on planting rate and depth. Seed burial may also be allowed, although care must be taken avoid burial next to water sources. Other potential options include disposal in an approved municipal landfill, use as a fuel source for a power plant or kiln, or incineration by a waste management facility.

For more information: Always be sure to check the seed bag label for specific details and restrictions about the product you are using. Depending on the product, there may also be rotational, plant-back, grazing or feeding restrictions. Futher details can also be found on the U of MN Factsheet about this topic at: http://z.umn.edu/shtseed.

Planting Window for Small Grains Already Closing

2013-04-19T14:47:27Z

While nearly all the small grains were seeded in Minnesota by this date in 2012, this spring is a different story. The unseasonably cold temperatures and relentless snow fall is setting us up for a (very) late spring. This will mean that, already, the planting window for small grains is closing for parts of the state. Understand that you can still plant spring wheat, barley, and oats after the last recommended date but that the chances to have good, competitive grain yields and quality are greatly reduced.

Check out this post from 2008 to understand how and why the planting window for wheat, barley and oats is what it.

Sauk Centre Hay Auction Report April 4, 2013

2013-04-17T19:44:44Z

by Dan Martens, Extension Educator Stearns-Benton-Morrison Counties
I am posting 3 items based on information from the April 4, 2013 Hay Auction at Sauk Centre Minnesota. The next auction is scheduled for April 18, starting at 12:30.

Apr 4 2013 SC Hay Auction.pdf.. A list of tested lots sold an bedding materials, grouped by bale type and quality.

History of Selected Lots 2012 2013.pdf .... Average and range of values for Medium Square Alfalfa in 25 RFV groups from 101 to 200 RFV, listed for each sale this year.

Graph 2001 to 2013 SC Hay Auction.pdf.... Line graph for market years since 2001 for Medium Square Alfalfa in groups by 25 RFV points from 101-200 RFV.