Agronomy Notes

December, 2002

Contents:

CORN
SOIL TESTING?
FORAGES AND PASTURES
RICE
SOYBEANS
SOIL and NUTRIENT MANAGEMENT

 

CORN

Dr. Erick Larson

Hybrid Trials - The new MSU Corn for Grain Variety Trials bulletin will be available this month. The corn yield data is also available now at your local extension office or by contacting Dr. Larson at MSU. This publication provides useful data for selecting hybrids to plant in 2003. I recommend growers plant several hybrids based upon three primary criteria - grain yield, stalk strength and maturity. High grain yield is obviously the primary consideration because grain is sold on a weight basis. However, variety trials may not reflect harvestable yield in a field situation unless stalk strength is considered. Leaning or broken stalks can lead to significantly reduced harvest efficiency in terms of harvest loss, time and fuel. Hybrid maturity influences harvest date and can impact profit through its effect on grain moisture. Hybrids grown may differ in maturity by as much as two weeks. Producers who market their grain at harvest may benefit from growing earlier-maturing hybrids because market prices usually decline through harvest.

Crop Rotation - Everyone is always searching for possible marketing opportunities. However, one method every producer can use to increase profitability and add stability to their cropping system is crop rotation. The reason is simple -- crop rotation significantly increases productivity of all your crops in the long run, while reducing input costs. Reports consistently indicate 10-20% yield advantages for cotton or soybeans grown in rotation with corn on Mississippi farms. Crop rotations normally improve yields because many weed, insect, nematode and disease problems build up when using the same management program every year in continuous cropping. Crop rotation systems effectively disrupt many of these cumulative effects, preventing problems and reducing input costs. Crop rotation allows the producer to attack the predominant weed problems by altering tillage systems, changing herbicide chemistry, and disrupting weed life cycles. Corn rotations can also improve soil physical structure by recycling more organic matter and changing from a tap-rooted crop to a fibrous root system. Numerous other beneficial effects of rotation have been reported, including improvements in soil fertility, soil moisture, soil microbes, and phytotoxic compounds and/or growth promoting substances originating from crop residues. Growers can maintain these benefits by continuing to rotate crops on a yearly basis. A crop rotation system also spreads risk in case of unpredictable problems.

How long should I grow corn? - The rotational benefits described above generally diminish every year after the first year in a rotation system. Additional yield, soil improvements, weed control, and nematode benefits are sometimes realized by a two year rotation, particularly if the field has been continuously cropped for a long time. However, yields will gradually decline and pest problems substantially arise the longer corn is grown continuously. This reduces potential gross return, while substantially increasing potential risk and/or input costs. Thus, I would not suggest not growing corn in the same field for more than two consecutive years.

SOIL TESTING

Dr. Keith Crouse

Soil testing is the basis of a sound soil fertility program. Therefore, a fertilizer recommendation is only as good as the soil sample submitted. Remember that you should always take the soil sample from an area that usually is about 10 acres or less in size. Take enough separate cores within the area for a representative soil sample, generally, about 15 to 20 cores. Take your soil cores from the surface to plow layer. Mix your soil cores thoroughly and submits a full box of soil for analysis. If soil results indicated low soil pH and fertility, you can make corrections following soil recommendations. For most crops, lime should be incorporated into the top 5 to 6 inches of the soil, preferably at least 3 months in advance of planting.

A fertilizer recommendation is only as good as the soil sample submitted; therefore, a representative soil sample is very important in any soil testing program. We have been receiving several samples with an insufficient amount of soil; please remind the clientele that we need a full box of soil. We are also still receiving soil samples without the correct payment or MSU Account number; therefore this delays the processing of the soil or tissue sample(s). We ask that you discard all old forms with the wrong cost for analysis and if a clientele wishes to be invoiced remind them to submit a MSU Account Number or a completed MSU customer identification form with the samples.

Remember that clientele can view soil sample results on the web. The address for clientele http:/ext.msstate.edu/special/soiltest.cgi. For the clientele to access soil test results, they need to know their AAA number, customer account number, county and report type, such as soil (field crops, pastures, commercial crops) or horticulture (gardens, flowers, lawn grasses, etc.).

FORAGES AND PASTURES

Dr. David Lang

Blast in Ryegrass-Grey leaf spot or Blast has damaged many ryegrass pastures this fall, particularly in the southern part of the state. It is caused by Pyricularia grisea and occurs during wet, moist falls like the one we have had. All ryegrass varieties are susceptible to Blast, so it didn't matter which ryegrass you planted. If you lost a field to Blast, it was likely not your seed, but rather an act of nature. The fields most affected by Blast were planted in early September before the tropical rains came at the and of September and again in early October. Ryegrass planted in mid to late October has not been as severely affected.

Small grains (Oats, Rye, Wheat, and Triticale) are not as severely affected by Blast, compared with ryegrass. Planting a mixture of small grain and ryegrass provides good insurance against early stand loss. All of the small grains have a forage yield (4000 to 6000 lbs/A) which is about half, compared with ryegrass (6000 to 10,000 lb/A). Oats provide good early growth, but Oats are more likely to winter kill in December or January if the temperature drops into the teens. Rye and wheat are much more cold tolerant and can be planted into late November. Nitrogen needed by small grains for forage is about 50 lbs N/A in the fall and 50 lbs N/A in the early spring (ex. 150 lbs/A of 34-0-0). Be careful to not over apply nitrogen (more than 60 to 80 units/A per application) to all cool season forages as they tend to accumulate nitrate and can lead to nitrate/nitrite toxicity.

The forage quality of small grains is excellent while the plant is vegetative. They stay vegetative throughout the fall and into early spring. Rye declines in quality the earliest as it matures in March. Oats mature 2 to 3 weeks earlier than wheat in late April and May. Oats retain forage quality longer than wheat. Animals will eat the seed heads of oats. It is possible to graze wheat through the winter and still harvest 25-35 bu/A of wheat, if you stop grazing by the first of March. This is feasible on an early (mid-October) planting of wheat, particularly during mild winters. Most wheat, other small grains, and ryegrass grown for pasture in Mississippi is grazed off to allow early growth of summer grasses.

The winter weather will determine whether a lot or a little hay will need to be fed. Ryegrass, small grains, and Tall Fescue will survive and regrow within a day or two of low temperatures in the twenties, but when the temperature dips into the teens and below, it may take a week or more for growth to recover. Water logged soil and cloudy days also reduces growth of these cool season plants. Plants need oxygen for their roots to breathe, just as we do. Plants also provide oxygen for us during photosynthesis. When the soil becomes saturated with water, the roots can not get enough oxygen and plant growth is severely affected or they die. Mild, sunny days are a blessing to both us and to our pastures and animals. Let us give thanks for the many good days given to us and pray that the days of rain will be enough, but not too much, and that the days of sunshine will be abundant, but interrupted by timely rains. Happy Thanksgiving !

NOTE: Prussic Acid/Cyanide in Johnsongrass and Sorghums is HIGH for 2-3 weeks following FROST. Do not allow animals to graze these. Johnsongrass hay needs to be dried completely to be safe, which will be difficult given the wet conditions.

RICE

Dr. Joe Street

I hesitate to write about economics of rice production because I am not an economist and have trouble managing my own finances. During these times of low rice prices, everyone wants to cut production costs to improve the bottom line but that is becoming more difficult to do. One of the best practices is timely management to avoid problem situations. Variety selection is very important in determining input costs and thus the bottom line. In an economic model developed in conjunction with MSU economist, Dr. Steve Martin, assuming the worst-case scenario of production inputs (i.e. if a variety is susceptible to a disease, a fungicide is charged to production), the most important aspect of production is yield. Although milling is important, with the current farm bill, overall yield is the primary factor in determining income. Unless a variety is selected for a particular situation such as red rice control with the Clearfield lines or a short season variety to spread harvest times, select a variety with maximum yield potential and minimum inputs. Lodging potential is an important issue but most of the high yielding varieties are somewhat susceptible, thus fertilizer management is more important with these varieties. The extra cost of harvesting down rice was not factored into the model. The economic analysis model is posted on our web site at http://www.msstate.edu/dept/drec and click on rice variety selection. This will provide a full economic analysis for several varieties and will also allow individual farm inputs to be plugged into the model. If you do not have Internet access, contact me for a copy of the analysis. Based on this model, which is based on yields from on-farm variety trials grown at seven locations throughout the state, Wells is the most profitable variety for 2003 followed by Priscilla and Cocodrie. Unless you are willing to drain for straighthead, do not plant Cocodrie on the lighter silt loam soils. I observed several fields with straighthead during the 2002-growing season.

As a reminder, if you plan to use Icon seed treatment for rice water weevil control, let your seed dealer know as soon as possible so you will have treated seed when you need them. Icon is very effective against the rice water weevil as well as the grape colaspis. If you have had a problem obtaining a good stand on the lighter soils following irrigated soybeans, you may have a problem with grape colaspis rather than seedling disease. Icon should improve emergence in these situations. The grape colaspis is generally not a problem on clay soils although I have seen it on those soils. Icon also offers partial control of chinch bugs and about 50 percent control of the cattail billbug, which has been destroying levee rice. Even if you do not use Icon treated seed in the paddies, using it on the levees could improve levee rice by reducing the chinch bug population after flushing young rice and reducing the cattail billbug damage.

SOYBEANS

Dr. Alan Blaine

As a new year approaches, there are several end-of-year tasks that need to be addressed.

1) Make varietal decisions as soon as possible. Variety trial information is available in the county extension offices. It should also be accessible on the internet prior to Christmas. If you find it helpful, we have finished compiling our variety list for the coming year.

Following 2002, I expect Group IV acreage to increase slightly to 55-60 percent of the total crop. Seed production acres were not immune to the problems many experienced this fall. It is due to these problems that I expect Group IV acreage to increase.

Group V seed supplies will be very tight this spring. Many seed growers' lost their V production. Group IV's should be in better shape since they are mainly grown further north. However, they may get scarce with additional pressure placed on IV supplies.

Do not delay making varietal decisions. As always the best varieties will go fast, but this is going to be the worst supply problem most have ever experienced.

2) Spread your risks by varying maturity groups. We have seen the exact same thing happen for two consecutive years. Last year the Group IV's, and this year on Group V's. Vary maturity groups to facilitate timely harvest.

3) Give serious consideration to crop rotation. All of the major row crops benefit from crop rotation and it should be utilized to the fullest.

4) The recent dry spell has allowed a window to complete soil sampling. Do not guess at soil fertility. I feel that many of the foliar disease problems we saw this year were due to low fertility. If you do not have time to pull samples but know the amount of harvested crop removed, we can help you maintain soil test levels.

Soil fertility has been overlooked on many acres in recent years. This appears to be worse in the Delta than in other areas of the state. A soil's fertility status has a tremendous impact on a plants ability to withstand disease pressure.

5) Perform necessary tillage as the opportunity occurs. Next years' crop is already going to be more expensive because of added tillage costs. In addition, if we are not afforded a tillage window prior to next spring, this will contribute to next years' crop being late. Later planting will impact yields.

Take time to access varietal information, and if we can help in anyway please do not hesitate to contact your county extension office.

SOIL and NUTRIENT MANAGEMENT

Dr. Larry Oldham

A great deal of remedial tillage will be needed following this record wet harvest season. (Remedial tillage is very different from recreational tillage.)The last issue of Agronomy Notes made a very good point about using this opportunity to get lime into the fields which are going to be tilled anyway. Lime will work in surface applications, but it is more efficient if tilled into the soil. Soil test to determine whether it is needed, buy good quality lime, and get it out.In cooperation with other MSU departments and state agencies, we are determining the ramifications of the Conservation Title of the new farm bill. This includes cost share practices applicable in Mississippi, implementing the Conservation Security Program for those already using Best Management Practices sometime during the life of the bill, and the role of third party Technical Service Providers in planning assistance.The USDA is sponsoring a Farm Bill Rollout Session on December 12 at Mississippi Valley State University in Itta Bena. More details on the program and participation will be available soon.Delta Agriculture Exposition

"Agriculture: The Essential Industry" is the theme for the 30th celebration of the Delta Ag Expo to be held Jan. 21 and 22 at the Bolivar County Exposition Center in Cleveland, Miss. The event, cosponsored by the Delta Ag Expo Corporation and the MSU Extension Service, offers ag-related seminars, more than 125 commercial and educational exhibits and an 11:30 a.m., Jan. 21 keynote address by Under Secretary of Agriculture, Bill Hawks. Also, as part of the 30th birthday celebration, the first 100 people who register that were farming or involved in the agriculture industry in 1974 will receive a special gift and will be entered for a chance to win a grand prize to be given away at the conclusion of the two-day event. The Expo opens daily at 8:30 a.m. and admission is free. Contact Don Respess or Kay Garrard at (662) 843-8361 or e-mail drespess@ext.msstate.edu or kayg@ext.msstate.edu.Department of Plant and Soil Sciences.

SEASONS GREETINGS

 

Department of Plant and Soil Sciences
Box 9555
Mississippi State, MS 39762

Will McCarty, Ph.D.
Extension Leader

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