CMEG Crop Management Extension Group

Field Crop News

Website Address: http://fcn.agronomy.psu.edu/

November 29, 2006    Vol. 06:27

IN THIS ISSUE:

Weather Outlook — Paul Knight

Unseasonably warm weather will linger until late Thursday. Cooler air pushing from west to east across Pennsylvania will be accompanied by periods of rain later on Thursday and into Friday. A disturbance is expected to form along the front, prolonging the wet conditions and delaying the arrival of colder air in the eastern third of the state until late Friday or early Saturday. Expect much colder (though just a bit below seasonal levels) weather during the weekend with snow showers in the northwest. A second surge of very cold air (daytime readings between 20–35F) should reach the region on Tuesday. It may be preceded by a period of light snow in central sections. The chilly air will remain through much of next week with another opportunity for rain or snow late in the week. It is very likely that more than half the state will notice its first measurable snowfall next week. A progressive weather pattern is expected during December with early month cold yielding to a mid—month mild spell.

Forages Take a Long Winter Nap — Marvin Hall, Forage Management, Crop & Soil Sciences

By now forages have been “put—to—bed” for 2006 and producers are hoping their forages will have a long winter nap. Energy production and storage for winter are finished and there isn’t much you can do now to harm or improve the condition of your forage. “The lot has been cast”. Weather will now play the largest role in determining how healthy your forage stands will look next spring when they awake from their winter nap. The best case scenario would be to have unsaturated soils with 6 inches of snow cover from mid December until March. Lack of snow cover, wet soil conditions and prolonged temperatures at or below 0 °F could spell disaster for “sleeping” forages.

Due to some fancy chemistry and metabolism, the buds on the crown or at the base of the plant can withstand temperatures of about 5 °F before they begin to freeze to death. Snow cover and dry soils help insulate the buds so that even air temperatures below –10 °F won’t cause the buds to freeze.

Saturated soils not only transmit cold temperatures to the buds quicker; they are also more prone to ice sheeting. A frozen layer of ice over a forage stand will restrict oxygen from reaching the plant roots and suffocate the plant. Wet soils are also much more prone to “frost heaving” (repeated freezing and thawing of the soil which pushes the crown above the soil surface and eventually snaps the roots) than dry soils.

With the forages “in bed” for the winter now is the time to focus on other aspects of your farm operation. However, don’t forget to conduct a thorough maintenance inspection of your forage harvesting equipment this winter because once the forages wake up next spring you’ll be too busy. As for me, I’ll bid you “a good night!”

Soil Quality Concerns with Biofuel — Sjoerd Duiker, Soil Management, Crop & Soil Sciences

Earlier this year, the journal Science devoted an issue to biofuels. In the editorial Stephen Koonin, Chief Scientist for BP, urged the scientific community to focus in on this issue, claiming “the size of the price is too large to ignore”. Biofuels gain interest as global oil demand surges, known reserves remain concentrated in certain regions, costs of finding and exploring new reserves rise, and concerns with GreenHouse Gas (GHG) emissions increase. A few years ago, the U.S. Government set the goal to produce 5% of the nation’s power, 20% of transportation fuels, and 23% of chemicals from biomass in the year 2030 (Roadmap for Agriculture Biomass Feedstock Supply in the United States). To achieve that, 1 billion tons of dry lignocellulosic biomass are needed annually by 2030. Much of the biomass is expected to come from corn stover. To illustrate the enormity of the task, just compare the total annual corn stover production in the U.S. This year’s crop is expected to be 11 billion bushels (15.5% moisture). At a harvest index of 0.5 the corn stover produced is 260 million dry tons. Fortunately, soil and water quality concerns have been part of the biofuel discussion since the beginning. It is recognized that not all corn stover can be removed without negatively affecting soil quality. The stover protects the soil from wind and water erosion, contains valuable nutrients that will be recycled to a future crop, and is needed to feed soil microbes and maintain soil organic matter contents. Soil organic matter helps to make soil resist compaction, improves water holding capacity and infiltration, and makes soil less sensitive to erosion.

The question remains: how much stover can be removed safely? A flurry of activity in this area has resulted in new insights. Five USDA researchers published a paper in the Journal of Soil and Water Conservation in which they formulated preliminary recommendations based on a review of past research. First, they recommended no biomass harvest from highly erodible land (HEL). Second, on non—highly—erodible land, they recommended that at least 3.4 tons/A of dry stover be left with moldboard plowing, and at least 2.4 tons/A with chisel plowing or no—tillage. Research indicates that these levels of above ground biomass need to be returned to maintain soil organic matter content. In a continuous corn system, this means that no stover could be harvested from a 160 bu/A corn crop with moldboard plowing, while about 1 ton/A of dry stover could be removed with chisel/no—till. Higher yields could of course accommodate greater stover removal. In a corn soybean rotation no corn stover could be removed at this yield level without harming soil quality. Soybeans have been found to have a “priming” effect on organic matter decomposition. So, while they don’t add much residue to begin with, they actually contribute to accelerated decomposition of existing soil organic matter. If cover crops could be established in no—till corn (and other crops in the rotation), it would enlarge the opportunities for crop residue harvest. However, it is generally too late to establish cover crops by the time the stover is dry enough to be harvested for biofuel. This raises several research questions, such as: is it possible to grow earlier maturing corn so cover crops can be established in a timely fashion? Can cover crops be established consistently with seed flown on a standing corn crop? Can cover crops be established at corn planting time or at the time of last herbicide application? These questions and more need additional work before we can answer them confidently.

References: Johnson, J.M.F., D. Reicosky, R. Allmaras, D. Archer, and W. Wilheim. 2006. A matter of balance: Conservation and renewable energy. J.Soil Water Cons. 61:120–125. Koonin, S.E. 2006. Getting serious about biofuels. Science 311:435. USDOE. 2003. Roadmap for agriculture biomass feedstock supply in the United States. USDOE, Washington, DC.

Agronomy Meetings Update — Greg Roth, Grain Crop Management, Crop & Soil Sciences

Recently, the American Society of Agronomy Meetings were held in Indianapolis and I found a number of interesting papers there relevant to grain production issues in Pennsylvania. I thought our newsletter readers might be interested in some of the issues that were discussed there.

An excellent backgrounder on the ethanol issue was released by the Council for Ag Science and Technology (CAST) at the meetings. It’s entitled Convergence of Energy and Agriculture: Implications for Research and Policy and is available here: (http://www.cast-science.org/cast/src/cast_top.htm). It discusses the value of grain for energy versus feed, the economic opportunities of biofuels, the potential impact on the livestock industry and proposes some policy changes that are needed to move forward on this issue.

Several papers focused on breeding crops for cellulosic ethanol. It was interesting to see the similarities between our objectives in breeding for fiber digestibility for corn silage and similar efforts in increasing the degradability of corn stover through modification of the cell wall chemistry of the plants. One Wisconsin report estimated that potential ethanol yields would be much higher for corn stover containing the brown midrib (bm) genes. Another interesting major effort (http://cellwall.genomics.purdue.edu/index.html) is focused on developing mutants for breeding purposes directed at cellulosic ethanol by focusing on the genes that control cell wall development (biogenesis) in corn.

One limitation of cellulosic ethanol is the expense of enzymes needed to break down the cellulose into sugars. One corn breeding project report focused on the successful development of a recombinant corn line that produced one of these key enzymes inside the corn itself. The genes for this enzyme were isolated from Acidothermus cellulolyticus, a thermophilic bacteria isolated from hot springs in Yellowstone. Consequently, the enzyme is only active when exposed to the high temperatures during processing for ethanol.

Another interesting paper evaluated the potential of self seeding cover crops. This Iowa State group evaluated the concept of only killing a portion of the cover crop using herbicides or cultivation and allowing some of the cover crop (rye, wheat or triticale) to seed itself in the standing crop (soybean) to provide winter cover prior to corn. The authors reported the self seeding worked well but the cover crops in corn reduced yields by 9–12% due to competition from the cover crop regrowth.

At least one paper reported on the trend for lowered seeding rate recommendations on soybeans. I visited with a noted soybean physiologist on this issue and we discussed the management necessary for these lower seeding rates to be effective. His point was that some factors like seed quality could be more significant at these lower seeding rates, since in the past the effects of reduced emergence was minimized by seeding rates that were often higher than necessary under ideal conditions.

An interesting Nebraska paper reminded me of some recent discussions on lower populations for drought prone soils. These researchers have been evaluating skip row corn (plant 2 skip 2, plant 2 skip 1) and finding that these actually yield slightly better than conventional plantings in low yield (<70 bu/acre) environments), apparently due to the timing of water availability and use. (Caution: trying this here could result in some phone calls and ribbing from neighbors).

One symposium during the meetings was devoted to transgenic corn, soybeans, and cotton. In general, adoption of these crops has been steadily increasing and insecticide inputs in corn and cotton have declined as a result. Transgenic cotton has resulted in a dramatic increase in conservation tillage in the south. A consistent theme from several speakers, however, was emerging glyphosate resistant weeds in various parts of the country, which is resulting in the need for alternative weed management strategies and eroding the value of the glyphosate tolerant crops.

Another symposium focused on canola production for biodiesel and biolubricant use. Several canola based biodiesel plants on the Great Plains have caused renewed interest in this crop.

Overall the meetings were very productive and upbeat, and provided lots of food for thought for future projects and demonstrations.

End of Season Weed Update — Bill Curran, Weed Management, Crop & Soil Sciences

Hopefully your weed control concerns are about over for 2006. There are certainly a few opportunities left before the New Year (i.e. weed control in wheat and maybe alfalfa), but hopefully most of you have already cleaned up and winterized the sprayer. I queried our county extension educators earlier this fall about weed issues that they dealt with during the 2006 season. I don't think there were too many surprises and suspect most of you dealt with many of the same problems. In corn and soybeans, burcucumber, glyphosate resistant horseweed/marestail, and pokeweed were at the top of the list of problems. In addition, lambsquarters escapes, horsenettle, and annual grass breaks in corn kept our farmers and applicators busy. In alfalfa and grass hay and pasture, Canada thistle and curly and broadleaf dock continue to be a problem, as is johnsongrass in some grass hay crops, spiny amaranth or pigweed seems to be increasing in many of our pastures in the Southeast, and Japanese stiltgrass or Microstegium vimineum, an increasingly common invasive exotic annual grass, is a growing problem in some Pennsylvania forests and is becoming more common in agricultural fields. The bromes including downy, Japanese chess, hairy chess, and cheat were the number one grassy weeds in winter wheat and barley. These winter annual bromes all look very similar and can very difficult to manage in winter cereals. Perennial brush species continue to cause trouble across the state with tree—of—heaven, sumac, multiflora rose, and autumn olive becoming increasingly common in no—till fields and in other areas that don’t receive much tillage or mowing. Managing these perennial weeds and others in CREP is increasingly a common problem facing some landowners.

In 2006, we did a number of field trials in corn, soybean, and other crops looking at new herbicides and other weed management tools. Some things that stuck out in my mind include Impact herbicide from Amvac, an HPPD inhibitor (same mode of action as Callisto) that came on the market in 2006. It did a nice job at controlling small foxtails and other grasses postemergence in corn. Bayer Crop Science is hoping to introduce Laudis, another product in the same herbicide family that also has post grass activity. Something other than the ALS—inhibitors (Steadfast, Option, etc.) or glyphosate for post grass control in corn is much needed. I was also pleased with the results from some of our pasture work. In particular, I was glad to see the activity of aminopyralid, the active ingredient in Milestone and Forefront, on smooth bedstraw. This is a perennial broadleaf that continues to spread and has become a real problem in grass hay, especially in the Northern Tier. We tested glufosinate resistant (Liberty—Link) soybeans for the first time in the new millennium. I’m looking forward to testing stacked glyphosate/glufosinate corn in 2007. I personally think a glufosinate product could have more of a place in both corn and soybean, especially with the increasing presence of herbicide resistant weeds. Finally, some of you had an opportunity to see or hear about the cover crop roller/crimper research that we are involved in. We’ve had some good and not so good results with the roller/crimper and will continue to investigate and identify where this type of tool/technology makes sense and where is doesn’t. I’ll report more on some of the results from our 2006 field research in future newsletters.

Act 38 Winter Manure Application Requirements — Jerry Martin, PA Nutrient Management Education Programf

Pennsylvania’s Nutrient Management Law (referred to as Act 6) was originally passed in the spring of 1993 and became effective on October 1, 1997 when the State Conservation Commission’s (SCC) regulations detailing the requirements under Act 6 went into effect in Pennsylvania. In 2005, Act 6 was revised and is now referred to as Act 38. In addition, the SCC has revised the nutrient management regulations which will become effective on October 1, 2006.

There are several significant changes to Pennsylvania’s Nutrient Management Program. A summary of these changes, along with a comprehensive source of information on the program, can be found on the program’s website (http://panutrientmgmt.cas.psu.edu/). The direct link to Revisions to PA Nutrient Management Regulations is http://panutrientmgmt.cas.psu.edu/pdf/lr_act38_Reg_Sum.pdf.

One of the key areas of change relates to manure application setbacks and winter manure application requirements.

The revision of Act 6 to Act 38 incorporated year—round manure application setbacks.
The Act 38 requirements are:
• Year—round 100 foot setback from streams, lakes, ponds and open sinkholes.
• Unless there is at least a 35 foot permanent vegetated buffer next to the stream, etc., in which
case manure may not be applied within 35 feet of the stream, lake, pond or sinkhole.
• Year—round 100 foot setback from active drinking water sources (wells, springs)

In addition, the revisions to the nutrient management regulations include specific requirements related to the winter application of manure.

First of all, a definition of winter is outlined. It is winter if one or more of the following conditions exist: between the calendar dates of December 15 – February 28, or when the ground is frozen to a 4–inch depth, or when the ground is snow-covered.

Secondly, fields that will receive winter applied manure must have a minimum of 25% ground cover.

Thirdly, there additional application setbacks required for winter applied manure. These additional setbacks are:
• 100 feet from prior delineated wetlands adjacent to exceptional value streams.
• 100 feet from intakes to ag drainage systems.

In summary, an Act 38 nutrient management plan for agricultural operations planning to apply manure during the winter must include a “Winter Manure Spreading Procedures” section which will list the fields or crop management units where winter application is either planned or restricted, the manure application procedures to be used including application, applicable setbacks, the ground cover and conditions of the field during application, and the type of manure planned to be applied.

Corn and Soybean Update — Greg Roth, Grain Crop Management, Crop & Soil Sciences

Both the corn grain and soybean variety test results have been posted on line on our corn and soybean website (http://cornandsoybeans.psu.edu). Yields in both trials were respectable, given the growing season and drought stress in August. Almost all entries in our corn trials now are traited hybrids. When evaluating variety performance information, be sure to consider the LSD value, which is an indication of the variation in the test. Hybrids that have yields within one LSD of the top hybrid are not significantly different than that hybrid.

Also, plans have been finalized for the Corn Soybean and No—till Conference at the Holiday Inn New Cumberland on Friday January 26. Check the corn and soybean website for a copy of the program and registration forms. A great lineup of speakers is on tap covering many of the key issues of the day in corn, soybean and no—till production including biofuels and grain markets, building soil quality and new breeding objectives for soybeans. Mark your calendar and plan to attend.

A Perfect Gift for the Holidays — Dwane Miller, Schuylkill County Extension

Are you wrestling with what to get that “special someone” for the holidays? We’ve got the perfect gift for the ag professional in your life. Give the gift of a Penn State Field Crop News e—mail newsletter subscription! Would you like it to be from “Secret Santa?” — no problem! All you need is a name and an e—mail address. The best news is it’s FREE!

We are pleased to be able to provide you with weekly updates on current issues during the growing season. Subscribing to our newsletter is simple! Just visit (http://fcn.agronomy.psu.edu/subscribe.cfm) and fill in the recipient’s name and e—mail address. They will be added to our database, and receive our electronic newsletter automatically. Readers can also subscribe electronically to this newsletter by sending an email message to: lac8@psu.edu with CMEG Newsletter subscription in the subject line of the email.

Now that harvest is nearly complete, our newsletter will be sent out less frequently. Starting in December, we will publish a monthly newsletter through March. After that, we’ll be back on a more frequent schedule again.

Contributors: State Specialists: Doug Beegle, Bill Curran, Erick De Wolf, Sjoerd Duiker, Ron Hoover, Dwight Lingenfelter, Jeff McClellan, and Greg Roth. Extension Educators: Kevin Fry (Armstrong), Andrew Frankenfield (Montgomery), Dave Messersmith (Wayne), Craig Williams (Tioga) and Dwane Miller (Schuylkill)

Editor: Dwane Miller, Extension Educator, Schuylkill County

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