September 20, 2007
In this issue
§ 2007
§ Checklist for improving soybean yields
§ Is nitrogen a moving target? Lessons from a 15-year corn rotation trial
§ Fertilizer supply – demand situation
§ MSU Soil & Plant Nutrient Lab for soil testing
§ Stewart’s disease (wilt) on field corn revisited
§ Grant funding program seeks innovative ideas for the farm and ranch
This is the last issue for the 2007 season of the Field CAT Alert newsletter. Included in this issue is an index of articles to help guide readers through the topics covered this year. Educators and specialists have worked hard to inform readers about current issues and crop production throughout the last few months.
Now we would like to hear from you! Please send us suggestions on topics that you would like us to cover in 2008. Also, please let us know how we can improve our print publication and web site (http://www.ipm.msu.edu/field-cat.htm).
Please send your comments to catalert@msu.edu or mail them to: Joy
Landis, MSU IPM Program, B18 National Food Safety and Toxicology Bldg.,
Thank you. -Joy
Landis, editor & Andrea Buchholz, asst. editor
Jan Byrne
Diagnostic Services
Over 125 samples were evaluated this year through the
sentinel plot system. In
Diseases most commonly found on soybean sentinel plot
samples included Septoria and bacterial leaf spots. These pathogens were mostly
found on lower leaves. Soybean rust, the disease of most interest, was not
detected in
This year the program was expanded to include a few other
legumes (in
Kurt Thelen, MSU Extension Cropping Systems Agronomist
George Silva, MSU Extension Agricultural Educator
The following checklist summarizes management practices that are proven to contribute to high-yielding soybeans. The practices are organized chronologically, beginning with the fall before the soybeans will be planted. This list can be used to identify opportunities for increasing soybean yields.
Avoid soil compaction
during harvest and fall tillage operations.
Soil compaction limits root growth, reduces nodulation, inhibits potassium uptake and promotes diseases such as sudden death syndrome and phytopthora. Yield losses due to compaction are variable and closely related to the availability of soil moisture. Yield reductions are more severe under dry conditions. Yield losses of 15 to 40 percent can occur.
Take soil samples for
nutrient and pH analysis.
Maintain soil pH between 6.0 and 6.5. Researchers from the
Collect and submit
soil samples for soybean cyst nematode analysis.
Soybean cyst nematodes cause more economic losses than any other soybean pest. Yield losses up to 15 bushels per acre can occur before symptoms are visible. Collecting and submitting soil samples in the fall before planting soybeans is the first step to reducing yield losses from soybean cyst nemtodes. Each farm can submit 20 samples to the MSU Nematode lab free of charge.
Apply lime and
broadcast potash if needed.
Apply lime in the fall before planting soybeans as lime typically takes at least six months to react in the soil. Potash can be safely applied in the fall to mineral soils having caution exchange capacities of 6 meq/100 g or higher.
Select high-yielding,
well-adapted varieties.
Variety selection is one of the most important management decision producers make. Utilize the Michigan Soybean Performance Report, information from seed companies and your on-farm trials to select high-yielding, well-adapted varieties. Consider the following characteristics: yield, soybean cyst nematode resistance, disease resistance or tolerance, standibility and maturity.
Inspect, repair and
calibrate planting equipment.
Uniform seed spacing in the row will improve yields. Small seed will plant more evenly and will experience less mechanical damage than large seed when planted with a drill equipped with a fluted metering system. Always calibrate your drill by seeds per foot of row or seeds per acre. Recalibrate whenever seed size changes.
Control weeds prior
to planting.
Always plant into weed-free fields. Delayed burn-down applications have resulted in yield losses of eight bushels per acre in MSU research trials. Tillage or herbicides can be used to control weeds.
Broadcast potash on
coarse-textured or organic soils if needed.
Fall applications of potash are not recommended on coarse-textured soils having CECs less than 6 meq/100 g or on organic soils due to the potential for leaching losses.
Apply phosphate
fertilizers if recommended.
Plant into good soil
conditions.
Adequate and uniform soil moisture, soil temperatures higher than 50ºF and a level surface will promote uniform seedling germination and emergence.
Plant soybeans early.
The first two weeks of May is considered the ideal planting
window for soybeans in the lower half of the
Inoculate seed
whenever soybeans are planted.
Researchers from
Consider a
soil-applied, residual herbicide application followed by a post-emergence
application.
Benefits include: reduced early-season weed competition, consistent control of weeds that emerge over a long time period, consistent control of hard-to-control weeds, and herbicide resistance prevention.
Plant at the optimum
seeding rates.
Plant 175,000 seeds in 7.5 inch rows, 150,000 seeds per acre in 15 inch rows and 130,000 seeds per acre in 30 inch rows.
Plant in narrow rows.
Narrow rows have been shown to increase soybean yields.
Plant at the optimum
depth.
Plant beans between 0.75 inch and 1.25 inch deep. In general, plant at the shallower end of the range when planting early and in no-till and plant at the deeper end of the range later in the season.
Plant a range of
maturity groups.
Planting a range of soybean maturity groups spreads your risk during the growing season, allows more of the crop to be harvested at the optimum stage and allows for timely wheat planting.
Use seed treatments
where warranted and provide uniform coverage of the seed.
Fungicide seed treatments are warranted when planting very
early or where pythium is known to be a problem (
Monitor fields
closely beginning at emergence.
Diagnose emergence problems early. Emergence can take 6 to 18 days depending on soil temperature and soil moisture conditions. If slow and uneven emergence occurs, dig up the delayed plants and look for disease or insect damage. Plant stands of 100,000 plants per acre will produce optimum yields if the plants are relatively evenly spaced. After emergence, continue checking fields for bean leaf beetles and black cutworms. Monitor weed heights and use this information to time post-emergence herbicide applications.
Apply post-emergence
herbicides timely and properly.
Apply post-emergence herbicides before weeds exceed four
inches tall as early emerging weeds cause the greatest yield reductions. Please
see the Soybean facts fact sheet entitled “Maximizing Glyphosate Performance”
at: http://www.ipm.msu.edu/cat07field/pdf/9-20glyphosate.pdf.
Identify and correct
manganese deficiency symptoms.
Yellow, stunted plants growing in dark-colored or high pH soils are likely deficient in manganese. Manganese deficiency symptoms always reoccur in the same areas as manganese does not build up in the soil. Check for deficiency symptoms and make foliar applications of manganese when the plants are six inches tall. Manganese sulfate produces the most consistent results. Refer to the Soybean facts fact sheet entitled “Maximizing Glyphosate Performance” for information on reducing antagonism when tank-mixing manganese carriers and glyphosate herbicides. (http://www.ipm.msu.edu/cat07field/pdf/9-20glyphosate.pdf)
Monitor and control
soybean aphids.
Begin scouting soybean fields in late-June and continue through mid-August. Make an insecticide application when the aphid populations reach 250 aphids per plant and increasing.
Harvest at the
optimum stage and adjust combine settings to maximize yield and quality.
Harvesting soybeans when the moisture content falls to 15 percent for the first time produces the highest test weight and yield. The probability of experiencing harvest losses due to shattering increases when the beans undergo several wetting and drying cycles after drying to 13 percent moisture.
Additional information about increasing soybean yields and profitability can be found online at http://web1.msue.msu.edu/soybean2010/.
Reference materials include:
“Adjusting a Grain Drill For Planting Soybeans,” J. E.
“Soil pH Influences Soybean Disease Potential Summary,”, C. Grau and N Kurtzweil, University of Wisconsin and G. Tylka, Iowa State University.
“Soil Applied Residual Herbicide Benefits in Soybeans,” C.Sprague, Field CAT Alert, Vol. 22, No.3.
“Soybean Seed Applied Inoculation”, K. Thelen and T.Shulz, Field CAT Alert, Vol, 22, No. 2.
Sieg Snapp and Lowell Gentry
Crop & Soil Sciences
Drought and hail storms have inflicted low and variable corn
yields on farmers throughout
Research findings are highlighted here from a 15 year
corn-based rotation trial located at MSU’s Kellogg Biological Station, in
southwest
Nitrogen remaining in the soil after a crop is harvested can be lost or captured. The primary loss pathway is by leaching, although denitrification and volatilization are sizeable loss pathways in specific situations.
Leaching happens when excess rainfall or irrigation causes rapid movement of water below the rooting zone. Nitrate is the main inorganic form of nitrogen that moves with water and is leached. The ammonium ion is quite different than the negative ion nitrate; it is a positively charged form of nitrogen that it is held tightly in soil by negatively charged organic matter and clay particles. This tightly held nitrogen, in the form of ammonium, is much less likely to be leached than nitrate. It is important to bear in mind that nitrogen is readily transformed from ammonium to nitrate by soil microorganisms through the nitrification pathway.
Denitrification is the process by which nitrate ions are transformed into gaseous forms of nitrogen by anaerobic microorganisms. This occurs generally under waterlogged soil conditions, and the gaseous forms of nitrogen produced are subsequently lost to the atmosphere. In specific sites in the soil, such as within the center of soil aggregates, denitrification can also occur even when the soil is not flooded. For substantial losses to occur, however, nitrogen application must be in excess of plant demand. If excess nitrate is in the soil, it is vulnerable to being denitrified whenever the conditions are right. Matching soil supply and plant demand for nitrogen, by using the proven yield for a given field to evaluate the amount of nitrogen to apply, is the foundation to reducing losses from denitrification and leaching.
Volatilization of ammonia is another pathway of gaseous loss of nitrogen from the soil, often when manure or urea-containing fertilizers are left on the surface and not incorporated. To minimize volatilization and loss of nitrogen from this pathway, fertilizer applied as urea or as manure should be incorporated into the soil.
Limiting the amount of inorganic nitrogen that is available to “leak” from the system is the key to limiting losses from leaching or denitrification. This poses a challenge, as nitrogen availability must also be sufficient to support optimum yields. A slow release source of nitrogen is an ideal way to improve both yields and limit losses. Slow release fertilizers are available, but can be quite expensive. Cover crops and manure can act as a form of slow release fertilizer, and have the advantage of improving the soil’s capacity to release nitrogen in a “just in time” fashion over time. Results from a long-term trial at Kellogg Biological Station are being used to reevaluate nitrogen credits for cover crops and composted dairy manure. Current recommendations are to use a nitrogen credit of 30 to 50 percent of the nitrogen applied in an organic form; yet our findings indicate this may be a significant underestimate of the nitrogen that is available over the long-term, particularly from manure applied in combination with cover crops. Improving our ability to estimate nitrogen contributions from organic inputs is our goal. This will help improve nitrogen efficiency while maintaining profitable yields.
Recycle nitrogen. Growing a cover crop or a forage crop is another way to improve nitrogen efficiency. The nitrogen remaining in the soil after harvest, especially following a poor growing season, is susceptible to leaching during the next winter and spring, however, it can be recycled. A winter cover crop can capture and release this nitrogen, thereby reducing the rate of nitrogen fertilizer needed on that field next year. Note: it is important to manage this recycled nitrogen so that residues are incorporated or killed with an herbicide, so that the residues decompose completely before a crop is grown. Residues provide a mineralizable, slow release nitrogen form, supported by microorganisms activity, to make nitrogen available, and support growth of the next crop.
Check your variety and your soil. There is some evidence that new crop genetics may have changed nitrogen efficiency compared to some historic varieties. In the past, some varieties may not have been able to use nitrogen as effectively to produce grain, compared to today’s high yielding hybrids. The take home message is that both plant nitrogen demand, and soil sources of nitrogen, are moving targets and require careful consideration in this time of increasing fertilizer costs. A presidedress soil nitrate test PSNT measurement is one of the best ways to evaluate your soil nitrogen supply capacity, which may be changing over time. Check with the MSU Soil and Plant Nutrient Laboratory to learn more about PSNT, see: http://www.css.msu.edu/SoilTesting.cfm.
Darryl Warncke
Crop & Soil Sciences
Increasing global crop production, especially in
A continued strong demand for phosphate is expected to
tighten the supply situation. Stocks of phosphate are at a recent low level.
Demand for potash is expected to be strong this fall and
during the coming year. In the
For additional information on fertilizer supply and demand, see the news articles from "The Fertilizer Institute" at the following link: http://ipm.msu.edu/cat07veg/PDF/9-19FertilizerPrices.pdf
Darryl Warncke & Jon Dahl
Crop & Soil Sciences & SPN Lab
The MSU Soil & Plant Nutrient Lab (SPN) provides soil
testing and plant tissue analysis services for farmers, homeowners, greenhouse
operations, consultants, agribusinesses, governmental service agencies and
research programs at MSU and other universities. Water samples are tested to
determine suitability for use in growing plants. Samples of soil and plant
tissue can be sent directly to the Soil & Plant Nutrient Lab at A82 Plant
and Soil Sciences Bldg.,
A listing of the services provided can be found at www.css.msu.edu/soiltesting under “Testing Price List.” Test reports include the test results plus recommendations. The MSU SPN Lab works closely with the MSU county extension offices and educators in providing information about testing and managing nutrient inputs for growing plants whether in home landscapes, greenhouses or on farms. Questions regarding testing services, results or recommendations can be directed to county extension educators, the SPN Lab or Jon Dahl at 517-355-0218 or Darryl Warncke at 517-355-0271 x 1270.
Diane Brown-Rytlewski
Plant Pathology
Last fall, an epidemic of Stewart’s disease occurred with foliar symptoms showing up on many field corn varieties in numerous locations across the state. Stewart’s disease is caused by the bacterium, Pantoea stewartii, and transmitted to corn by the corn flea beetle when it feeds on foliage and deposits its bacteria-laden feces in the feeding wounds. The flea beetle overwinters as an adult in ground litter and harbors the bacterium in its gut. With the mild winter we experienced, there were concerns that overwintering beetles might cause the more serious wilt phase on field corn seedlings in spring instead of the foliar lesions that appeared in August and September when the corn was in the milk to dent stage. No wilt symptoms were reported on field corn this spring, although one grower did report heavy losses in a field of sweet corn.
However, this fall,
Stewart’s disease is appearing again, from infections that took place after
tassels emerged. The leaf lesion phase is caused mainly by the first summer
generation of flea beetles. At least two overlapping generations of corn flea
beetles occur over the summer, with the first generation peaking about mid-June,
and the second about four to six weeks later. Although it is less severe and in
a more limited geographical area, it still seems to be affecting a number of
varieties. Most of the fields affected have been in the greater Thumb area,
including Sanilac, Tuscola,
Fourteen out of 15 varieties from
Earlier this year,
Extension educators in
The North Central Region
Sustainable Agriculture Research and Education (NCR-SARE) Program is seeking
innovative farmers or ranchers who want to implement a new, sustainable, idea
to improve their operation. NCR-SARE is currently accepting applications for
their 2007 Farmer Rancher grant program.
NCR-SARE awards grants to farmers
and ranchers for on-farm research, demonstrations and education projects. By
providing funds ranging from $6,000 per individual grant to up to $18,000 for
grants awarded to groups of three or more, NCR-SARE helps facilitate essential
agricultural research and development.
Beverly Pender is an urban farmer in
“Our objective is to promote urban farming and to teach the community about healthy food production,” Pender explained.
Pender’s grant is just one example of the wide range of projects that NCR-SARE has funded over the years. Other funded topics include pest and disease management, soil conservation, local marketing, public education, waste management, agri-tourism, crop diversity, aqua-culture and many others.
NCR-SARE grants are awarded based on the applicants ability to describe how their project will be sustainable in terms of having long-term profitability, being good for the environment, producing healthy foods, being socially responsible and supporting their community.
Last year NCR-SARE funded 52 Farmer Rancher grants totaling
$400,037. This year farmers and ranchers throughout the North Central Region
will once again have the opportunity to apply for roughly $400,000 in grant
assistance. The 12 states that comprise the North Central Region are
Grant proposals are due in the NCR-SARE office by December 3, 2007. Interested applicants may contact Joan Benjamin with NCR-SARE at 402-472-0809 or ncrsare@umn.edu. The current Farmer Rancher Grant Call for Proposals application can be found on the NCR-SARE web site at http://ncr.sare.org/prod.htm. Previous project reports are made available through the national SARE web site at www.sare.org.
North Central Region - Sustainable Agriculture Research and Education Farmer Rancher Grant Program
402.472.0809 or 1.800.529.1342 (toll free)
Ned Birkey
The weather has been cool to warm and generally dry over the
past two weeks. This has made for great tomato harvesting weather. Temperatures
may have dipped just below 32ºF early Sunday morning in the
Alfalfa fourth cutting has been made in some fields, with other fields recovering nicely from a good third cutting. Potato leafhoppers are not a problem. New seedings have gone in, some a bit late depending upon the fall weather. Prices have moderated, temporarily in my opinion, with the bigger third cutting. There is very little hay in storage from this year to get us through the winter and spring.
Corn silage harvest is over half done and most grain has dented and some nearing physiological maturity. Giant ragweed has had a great year. One farmer, who is 5’5”, had a photo taken of him standing near some corn and ten-foot tall giant ragweed plants. I have not seen any corn harvested for grain yet. Farmers are wondering about yields, which I expect to be widely variable in the four county areas here. Corn earworms are still in the sweet corn.
Soybeans are turning yellow, dropping leaves, with an occasional field that is harvested. I expect yields to be generally fair to good and have not seen any fields that I think are great. Only the double crop soybeans are still generally green.
Wheat planting
will start next week in
We have a harvest moon coming next week, with the first full moon after the start of fall. Some farmers still say that is when we will have a killing frost. Weed pressure is terrific in some corn and soybean fields, so a frost will help. I expect combines to begin next week in some fields, as crops seem to be maturing a bit earlier this year. An earlier frost date this year should not be a big problem except for double crop soybeans, which is usually a gamble. The Detroit Red Wings open their exhibition season at home next week, so I wonder if that is a sign of early winter weather?
Fred Springborn
Rain showers on September 10-11 yielded 0.5- 1.0 inch of rain over much of the area in the past two weeks, but by in large it has been quite dry for the past two weeks. High temperatures have been moderate with highs in the upper 60s to low 80s for much of the two week period.
Wheat planting is underway with good soil conditions across the area.
Corn silage harvest is nearly complete as stalk moisture is going down rapidly. Much of the crop is mature and about one percent harvested. European corn borer numbers remain low in the pheromone traps. Corn earworm numbers in the traps have also been low over the past two weeks.
The soybean crop is developing rapidly. Harvest will be underway shortly.
The dry bean harvest is well underway with mixed yields reported. Dry land yields are generally well below average. A few fields have had late European corn borer injury showing up in the harvested beans.
A few dairy farms are still harvesting alfalfa from older stands that will be torn up this fall or spring. Alfalfa needs to put on regrowth now to build its reserves to overwinter. Many are planning to take a cutting after dormancy next month.
Jeff
Andresen
Agricultural Meteorology
Geography
An upper air troughing feature across the western United
States will lead to southwesterly flow across the Great Lakes region during the
next several days, leading to above normal temperatures and to the passage of
at least two frontal boundaries through Michigan. A cool front will move from
northwest to southeast across the state Friday, September 21, before stalling
out across the
For the first frontal passage Friday, moisture is generally lacking and for most of the state only scattered showers and thunderstorms are expected, with best chances for rainfall across extreme northern sections of the state. Most areas of the state will remain dry. Precipitation that does fall will generally remain in the 0.10-0.25 inch category where rain occurs. High temperatures will generally range from the mid- to upper 70's Thursday, and then increase to the upper 70's north to upper 80's south on Friday along with strong southwest winds (ahead of the cool front). Low temperatures will generally range from the upper 40's north to upper 50's south on Thursday, warming slightly to the 50's to low 60's Friday and Saturday. Shower and thunderstorms will be possible once again across the state as the next frontal boundary approaches from the west. More moisture is expected ahead of this front, increasing the chances of a more widespread rainfall event in most sections of the state late Monday into Tuesday.
Further ahead, latest medium range forecast guidance
suggests a general continuation of upper air troughing across the western