- Corn Ear Tip Back
Corn Ear Tip Back
It appears corn ears have tipped back more than normal in a large number of fields and seed brands across a wide geography in the corn belt this year. What can we blame this on? Well, the list is long for possible causes of ear tip back from year to year. Drought, excessive post pollination heat, shortage of nutrients, hail, insects, disease, high planting populations, and genetics are just some of the many things that get blamed for this. Sometimes it’s a combination of more than one and sometimes it’s hard to pinpoint anything at all for why it happens. I would agree that in some instances loss of nitrogen can be to blame in those fields that were water logged early and often this year. But what about those fields showing excessive tip back that we know are not short of fertilizer, did not get flooded or hailed, have no real disease or insect pressure, experienced no drought, and are not planted at high populations? What about these that look absolutely beautiful and healthy but when you walk in and pull back ears, you see 3 inches of tip back? The answer isn’t always clear cut and may be fairly complex. One thing is certain. A stress or stresses at the time period following pollination triggered the corn plant to abort some of the kernels at the tip of the ear. Although there has been very little drought stress to our corn crop this year we have to remember drought stress and heat stress are not the same. A corn plant would rather go through its ear fill period at moderate temps than at temps much above 86 degrees. We did have a prolonged period of excessive temperatures during the post pollination period this year. Those nights where temps failed to dip below 70 degrees can be especially detrimental to grain fill and starch accumulation. This may have played a direct roll in some of this excessive ear tip back we are seeing in some fields this year. I would not try blaming it on any one hybrid either. Yes you will see some hybrids do it much worse than others at locations but I think it’s more about the way that specific hybrid responded to it’s environment at that location than the hybrid itself. The above picture shows two ears that I pulled from fields last week over 100 miles apart. The hybrids are both tipped back significantly and they share absolutely no genetic relation. In summary, the corn plant is a complex plant physiologically and reacts to the many different curve balls mother nature throws its way. As always, keep an open mind when trying to determine why things happen in a corn field. Often times there is no one absolute right or wrong answer.
Ryan Spurgeon
Hoegemeyer Hybrids - Planting Date Decisions
If you ask ten different farmers for the right time to plant corn, you are likely to get ten different answers. Some wait for a specific date. Some wait for a specific temperature. And some wait to see what their neighbors do. In reality, they may all be right. Every situation is different because of soil type, drainage, tillage practices, number of acres and hybrid maturity. All of these factors need to be evaluated when determining a date for planting corn. That being said, there is a slight advantage to being on the early side. There are many benefits to planting early, however the primary benefit is that your crop will reach maturity quicker. A corn plant uses the most energy during its reproductive stages. Because the corn plant gets this energy from the sun, it is desirable to have the longest days of the growing season closest to the reproductive stages. June 21st is the longest day of the year; after that date, the days get shorter. Therefore, reaching the reproductive stages as close to this date as possible will give the plant more energy, resulting in the potential for higher yields.
In addition, early planting can help reduce the amount of damage from disease. For example, the amount of yield loss due to corn leaf and ear rot diseases can be reduced if the plant is more mature. Diseases such as Grey Leaf Spot, which occurs later in the growing season, will not cause as much damage in more mature plants. Planting early will also decrease the chances of having a black cutworm problem. Black cutworms won’t start “cutting” until their fourth instar and corn is most susceptible from the spike to V3 stage. So, the sooner you reach the V4 stage, the better off you will be. If circumstances require late planting, protection from black cutworm can be attained via the Herculex trait.
There are also some risks assumed when planting early. The most prominent are disease and frost. The cooler the soil, the longer it takes for the seedling to emerge, which makes it more susceptible to seedling rot and damping off. Cooler soil can also lead to uneven stands. The wetter the soil, the longer it takes to warm. When moisture conditions vary in the field, the temperature will also vary and this is what can cause uneven stands. In case early season problems are encountered, there is more time to make replant decisions if you plant early.
In most cases, planting a week early will mean less yield loss than planting a week late. If conditions are right for planting, but planting is intentionally delayed a week, weather changes may delay planting for another week or more. Regardless of planting date, it is best to start with your fuller season hybrids on your warmest soils. These soils tend to be in well-drained, upland fields where there is little or no residue cover. Soil temperatures in fields with heavy residue can be as much as fourdegrees cooler than bare soil. Though reaching maturity early is advantageous, it is important not to sacrifice a fuller season hybrid with an earlier one. According to a University of Missouri study, where normal adapted hybrids were compared to earlier ones, the adapted hybrids showed a 15% yield advantage regardless of planting date. In the end, it is important to understand one’s unique circumstances, evaluate the options and weigh the risks to achieve everyone’s desired outcome: timely planting with a good stand.
- Replanting Corn & Yield Loss
When Should Replant Be Considered?
The replant decision is a tough call. Things to consider in this decision include:- Productive Plant Population: You will need to determine the productive plant population in several areas of the field to help estimate the potential yield of the field if left as is.
- Stand Uniformity: If the productive plant population is not uniformly distributed within the row, additional yield loss will likely occur.
- Original Planting Date: The original planting date plus the remaining productive plant population will be used to estimate the yield potential of the field.
- Likely Replanting Date & Target Plant Population: These will be used to estimate the yield potential of the replanted field.
- Likely Replanting Costs: The cost of replanting a damaged field often makes or breaks a replanting decision. Usual costs include seed, fuel (tillage and planting), additional pesticides, and additional dryer fuel.
- Expected 'Normal' Yields: Estimates of the yield potentials of the damaged field and the replanted field are based on a percentage of 'normal' yield for the field in question. Unless you are excellent at predicting yields for the coming year, consider using a five-year average.
- Expected Market Price for Corn: The dollar gain or loss by replanting obviously depends greatly on what you expect to receive for the grain this fall. The volatility of the grain market this year makes it especially difficult to plug in' a value for determining a replant decision. Use your best guess.
Plant Population?
Row length equal to1/1000
acre for various row widths.Row width Row length equal to 1/1000 acre 20" 26' 1" 28" 18' 8" 30" 17' 5" 36" 14' 6" 38" 13' 10" 40" 13' 1" To figure the plant population, use the chart above:
- Using the chart, find the row width of your planter
- Using the chart, determine how many feet it takes to make 1/1000th of an acre (example: 30” = 17’ 5”)
- At multiple locations throughout the field, count the number of remaining plants in 1/1000th of an acre lengths
- Average your 1/1000th of an acre counts
- Multiply the average of your counts times
- 1000 for the average population in the field
Stand Uniformity?
Corn plant skips or gaps in the field cause yield loss. Longer skips usually reduces yield more due to fewer plants, uneven plant placement or possible weed competition. The following chart lists the plant spacing at different row widths and plant populations.- Corn plant spacing (inches) at four different plant populations and row widths
Row width (inches) Plant population 18,000 22,000 26,000 30,000 30 11.6 9.5 8.0 7.0 36 9.7 7.9 6.7 5.8 38 9.2 7.5 6.3 5.5 40 8.7 7.1 6.0 5.2 Original Planting Date & Stand Compared To A Later Plant/Replant Date & Stand.
- Corn yield expressed as a percent of the optimum stand and date.
Plant Date April 20 to May 5 May 20 June 1 June 10 Established Stand* %Yield 26,000 to 30,000 100 90 81 67 22,000 96 86 78 64 18,000 91 82 74 61 14,000 80 72 65 54 10,000 65 59 53 4 * Assumes reasonably uniform stands. Source: G.O. Benson, Iowa State University
If Corn Plants Are 100% Defoliated At Different Growth Stages, What Is My Potential
Yield Loss?
- Winter Annual Weeds & No-Till Farming
Winter Annual Weeds & No-Till Farming
What Are Winter Annual Weeds?
An annual weeds job is to produce seed so that the species will continue on next year, everything else is secondary. Unlike summer annual weeds such as foxtail or velvet leaf which typically germinate and produce seed within a summer growing season, winter annuals actually germinate in the fall and begin growing before winter. During winter these weeds go into dormancy, but at the first signs of spring, winter annuals come out of dormancy, bolt and produce seed before corn and beans are usually planted.
What Are Some Winter Annual Weeds?
Some commonly seen and problem winter annual weeds include henbit, horseweed (mares tail), pennycress, shepherds purse, curly dock, perennial dandelion and the mustard family.
Are We Seeing More Winter Annual Weeds in No-Till?
As the use of no-till farming increases, winter annual populations and problems in the fields seem to be increasing. Many producers, especially in dry-land situations, have found that one of the benefits of no-till is that it helps conserve moisture but, no-till may not interfere with the life cycle of winter annual weeds like tillage does. Consequently, many no-till users feel they are having more winter annual weed problems in their fields than they had when they used more tillage. Another speculation on why winter annuals are popping up more in no-till fields is the increased use of Roundup-Ready soybeans. Since Roundup has no residual there is no long term control of weeds. When conventional soybeans were the norm, traditional herbicides provided residual control that kept many of the winter annuals from germinating or growing in the fall.
Can Winter Annual Weeds Do Much Damage?
Research at the University of Nebraska shows that winter annuals can use as much as three inches of soil moisture in 30 days. In another study, Agriculture and Agri-Food Canada, concluded that 8% to 11% of the soils moisture could be saved by controlling winter annuals early. “Winter Annual Weed Pest Alert” Remember, patches of winter annuals are a preferred area for cutworms to lay their eggs in.Controlling Winter Annuals?
The biggest issue for control is timing. Herbicides used to control winter annuals work best when applied before the weeds have bolted. Typically, this means checking fields early and spraying as soon as temperatures warm up enough for fast plant growth to begin. Studies done by the University of Nebraska regarding spring applied products and the percentage of winter annual weed control experienced are (1) 2,4-D with 65% control, (2) 2,4-D plus Banvel with 83% control, (3) Atrazine COC with 100% control and (4) Roundup with 93% control. The University of Missouri did a fall application study for henbit and documented the following results (1) Canopy with 100% control, (2) Canopy XL with 98% control and (3) Sencore with 94% control. In most cases, a herbicides effectiveness or control can also be influenced by the air temperature at which the herbicide was applied. In many situations, cooler application temperatures than the manufacturer recommends may render a herbicide less affective.CREDITS: University of Nebraska
University of Missouri
Kansas State University - Selecting a Corn Hybrid
The Perfect Hybrid There is no perfect hybrid that fits every situation or need. Therefore, when selecting those hybrids for your farming operation, you’re the one that must assess your farming operations strengths and weaknesses in order for you to properly evaluate the hybrids that have the
What Are Some Corn Hybrid Selection Factors to Consider?
-
Genetic Diversity
Don’t put all of your eggs in one basket and plant one variety. No two years are the same and planting a portfolio of genetic backgrounds will give you diversity to help give you yield consistency from one year to the next. -
Seedling Vigor
Because you most likely can’t plant your entire crop in one day and in one field, chances are you will be planting in different weather conditions, soil types, soil temperatures, and overall environments. Plant the hybrids at the times and in the areas they can best handle. -
Desired Population
Each hybrid has its most advantageous population at which it expresses its uppermost yield potential. Consider ear type and its interaction with the corn production system you use in your farming operation. -
Ear Type
Ear types are either fixed or flex. With-in reason, fixed ear types make the same size ear regardless of population while flex ears can make either longer or girthier ears if competition is decreased by reducing population. -
Tillage Practices
The less that you till the fields, the greater are the chances you will encounter cooler soil temperatures, wetter soils, and more residues which may well mean increased insect pressures at or after seed germination. -
Continuous Corn or Rotation With Another Crop
Crop rotation tends to break insect and weed cycles. It could also help in reducing some of the residue buildup that possibly will be the host for insect and disease survival. Poorer stalk quality might also be a problem in many continuous corn on corn fields. -
Dryland, Irrigated or Drought Tolerance
Hybrids that can flex in ear length or girth fit dryland or drought conditions better. Irrigated or adequate moisture situations are more manageable, so hybrids that can handle high populations, have high yield potential, or produce determinate ears are good choices. -
Soil Fertility, Soil Type and Topography
Lower fertility soils get the best yield potential from flex ear type hybrids and varieties that do not need higher populations to produce yields. Another advantage of flex ear hybrids in lower fertility soils is at lower populations less vegetative matter is produced. Lower plant population means a smaller amount of vegetative matter is produced so fewer plants means less demand for moisture and nutrients needed from the soil. Topography, what’s the lay of the land? Canopy cover is advantageous to help conserve moisture and shadow out weeds. Consider the hybrids height when planting in hills or on poorer soil types. -
Plant Growth Type (early or late flower for hybrid maturity)
Flowering or pollination in relation to length of grain fill is a yield consideration. Later flowering hybrids many times produces a larger stature hybrid, the grain fill period for yield potential is shorter, and yield may be hurt if a prolonged period of heat coincides with the shorter grain fill period. Shorter grain fill periods sometimes make softer kernels and lower test weights. Early flowering hybrids use longer grain fill periods to generate yields but plant stature may be smaller. Areas where heat could be a problem during grain fill choose to use early flowering type hybrids. -
Stalk Quality and Root Lodging Resistance
Stalk quality is the ability of the plant to stand and stay intact through harvest. The two main sources of stalk quality are rind thickness and staygreen. It is not necessarily the diameter of the stalk, but the thickness of the rind that provides resistance to lodging. The rind is made of lignin and lignin provides the rigidity that keeps the plant upright into the harvest season. -
Drydown and Grain Test Weight
Drydown, or the rate at which moisture leaves the kernel, is influenced by husk looseness, plant staygreen and test weight. Test weight is influenced by how staygreen a hybrid is. Hybrids that are fast-die and fast-dry are more apt to have lower test weights. -
Corn Borer and Insect Tolerance
Hybrids differ in tolerance to corn borer. Hybrids that are planted early or grow fast early are more attractive to first brood corn borer. Later planted or immature corn is more attractive to second brood corn borer. If other insects are a concern, consider genetically altered varieties or ordering specific seed treatments for the varieties you choose. -
Herbicide Tolerance
Herbicide tolerant hybrids are becoming more popular and work well when properly applied and utilized. However, we also need to be good stewards of herbicide use and understand that we still need to rotate herbicides. Good stewardship will help delay weed resistance to a herbicide and prolong its overall effectiveness. According to the chemical company’s representatives, no new herbicides are on the horizon. If we abuse the herbicides we are using today, and resistance becomes a problem, there is not a new lifesaving herbicide waiting to replace it!
-
Genetic Diversity
- Meaningful Product Comparisons
Gathering good yield information during harvest is important. Making accurate product comparisons with your own yields will help ensure that you can glean the most profitable results next year.
Remember that while product performance measured in bushels-per-acre, adjusted for moisture, is the primary consideration when evaluating hybrids, other characteristics can often play a large role in whether or not a product fits your farming operation. Consider this scenario: a top yielding variety in an unusually dry year catches your attention and you decide to plant it on 75 percent of your acres next year. But next year your micro-climate returns to near normal rainfall and diseases that had been common before return. The product that did so well when it was dry underperforms because it was selected in an environment that was not typical for your area.
Here are three important suggestions that can help you make meaningful product comparisons:
- Gather results from several sites within your area of operation, rather than a single test from your own farm. Decades of university and independent on-farm studies have shown that a broader collection of harvest data will help you determine accurately what the “best” yielding varieties were.
- Compare varieties of similar maturity and technology traits. In other words, compare Bt hybrids with Bt hybrids and group II soybeans with group II soybeans. Most producers would like to know each year whether Bt technology paid for itself or if a fuller maturity hybrid was best. Those are excellent questions and you should make those comparisons for your farm. But when evaluating plot results, you’ll get accurate information by comparing varieties with similar maturities and technologies. And that should give you results that you can translate into good decisions for next year.
- Contact your district sales manager (DSM) if you measure your yield in side-byside plots or evaluation plots with a weigh wagon or yield monitor. Your DSM can assist you and will submit your data so it can be entered in our product comparison database. Your harvest results will become part of a meaningful, multi-location comparison of many hybrids that will be available this fall and winter for you and other customers.
- Hybrids for Ethanol Production
Ethanol production is expanding at a very rapid pace with new plants coming on line and more in the planning and construction phases. As a seed company, Hoegemeyer is working to supply the hybrids and the agronomic information that our producers need to maximize production for themselves and for the ethanol plants. First, it is important to understand that there are three main elements that contribute to the amount of ethanol that a bushel of corn produces. High extractable starch (HES) is the key ingredient in corn that is needed to produce ethanol. The three main elements that determine the amount of HES are:
- Overall grain quality
- The hybrid’s characteristics
- Agronomic practices
We recently tested 10 Hoegemeyer corn hybrids at a central Nebraska ethanol plant to determine their HES rating. A Near Infrared (NIR) test is done on every load of corn that enters the plant. The test takes about one to two minutes. The samples we tested were all from high yielding test plots. Several of our hybrids were rated very high in extractable starch and some of them were among our highest yielding hybrids, too. In fact, one of the hybrids (2679) had the second highest HES rating of all the hybrids ever tested to date by this ethanol facility.
We tested another sample of this same hybrid that had a barely noticeable amount of mold in it. The mold caused the extractable starch content to drop dramatically, making it one of the lower tested samples. So, it appears that producing very clean, high quality grain is the first step in ensuring your corn will have a high extractable starch (HES) rating. Why would poorer quality grain reduce ethanol production? One of the reasons is that it takes enzymes to help in the starch extraction process and poorer grain quality, with mold and foreign matter, interferes with the enzymes and their action. As a result, the efficiency and productivity of the ethanol plant is affected. Damage from insects, harvesting and heat drying will also decrease extractable starch. So, care must be taken in how the corn is handled during harvest and in storage.
Hoegemeyer is currently working to collect hybrid samples so we can make accurate and specific recommendations to those customers who sell their corn for ethanol production. There are a multitude of websites on ethanol if you want to learn more. One you might check out is ethanolfacts.com.
- How to Lower Soybean Seed Cost
How to Lower Soybean Seed Cost
How to Lower Soybean Seed Costs
The seeding rate for soybeans is determined by the desired harvest plant population to achieve high yield and the expected loss of plants (or seeds) between planting and harvest. Recent comparisons indicate that stand loss from V3 to R8 ranged from 10 to 15 percent. Additional stand losses due to germination and seedling diseases prior to stage V3 probably range from 5 to 15 percent. Therefore, the planting rate should be from 15 to 30 percent above the desired harvest plant population.
Table 1 shows the results of a three-year study at five locations in Iowa. Narrow rows (7.5 inches at one location, 10 inches at four locations) were compared with wide rows (30 inches). A soybean drill was used to plant the narrow rows and a planter was used for the wide rows. The target plant stand was the same for both row spacings; however, manufacturers' recommended machine settings for each stand resulted in different harvest stands, with the wide rows having fewer plants at harvest than narrow rows at each target stand. The highest target stands resulted in the largest gap between target stand and harvest stand for each row spacing.
Plant stand
targetNarrow rows (7.5 & 10 inches)
Wide rows (30 inches)
Harvest stand Grain yield (bu/acre)
Harvest stand Grain yield (bu/acre)
80K* 94K 47.9 73K 46.3 120K 133K 50.2 110K 49.3 160K 157K 50.9 135K 49.8 200K 186K 51.6 165K 50.6 240K 221K 51.4 189K 49.8 Grain yield did not differ significantly for harvest stands above 100,000 plants per acre in either row spacing. The narrow-row harvest stand of 133,000 plants per acre produced 50.2 bu/acre compared with 51.6 bu/acre with a stand of 186,000 plants. In wide rows, the harvest stand of 110,000 plants per acre produced 49.3 bu/acre and the stand of 165,000 plants per acre produced 50.6 bu/acre. A harvest population of less than 100,000 plants per acre produced a significantly lower yield than stands of 110,000 plants or more. These studies indicate that the producer should plant enough soybean seed to have a harvest stand of at least 100,000 plants per acre. The cost of additional seed, however, must be taken into consideration before planting excessively high plant stands.
Credits: Keith Whigham, extension agronomist, Department of Agronomy,
Iowa StateUniversity Extension, Integrated Crop Management issue IC-480(23), (10/12/1998) - Herbicide Resistance Management
In recent years more and more farmers have become aware of weeds that have become resistance to popular herbicide programs. As agricultural production continues to intensify farmers have increased their use of herbicides to manage weeds. In addition, farmers are relying more on continuous use of herbicides with similar modes of action (MOA) or even the same herbicide. Farmers have been selecting and developing weed resistance since the late 50’s when the first weeds were identified resistant to 2,4-D and atrazine. The number of weeds resistant to herbicides has grown to over 250 species worldwide. The number of species resistant to a given herbicide family range from over 70 species resistant to the triazines (i.e.: atrazine) and ALS/AHAS (i.e.: Glean, Spirit, Pursuit) herbicides, to just a handful for glyphosates, and only a couple of weeds for the chloroacetamide (i.e.: Dual, Harness) herbicides. With the exception of a few new herbicide derivatives, only the newest herbicide family, the HPPD mode of action group, has not yet had any weeds identified as resistant. The only herbicides presently labeled in this class are isoxaflutole and mesotrione (Callisto). There has been only two new herbicide MOA’s in the past 15 years, including glufosinate in 1994 and the HPPD’s since 2000. It is unlikely that there will be any new herbicide MOA’s launched within the next 8-10 years. The lack of new MOA’s will put increased pressure on farmers to better manage the products we have today to prevent further losses in weed control options. Weed resistance is defined as the inherited ability of a weed to survive a rate of herbicide, which would usually give effective control. There are differences in opinions on exactly what “use rate” defines resistance. Most researchers follow the WSSA’s guidelines that once a weed is no longer controlled at a rate 6 times greater than before, it is considered resistant. For example, if 1 lb per acre provided effective control of a given weed, then if a portion of that weed’s population could no longer be controlled at 6 lbs per acre, then the non controlled weeds would be considered resistant to that herbicide MOA. One of the common misconceptions is that weeds “mutate” to become resistant to herbicide treatments. Weeds actually do not mutate very easily but primarily rely on their diverse genetic codes to select for resistance to a specific herbicide family. There are two typical ways that weed resistance develops within a population. The first is through a simple selection process. In some weed species there exist a small number of weeds that have the inherent ability to bypass a given herbicide’s mode of action. If a farmer makes a treatment and kills all but these “resistant” weeds, they remain to produce seed or pollinate with others. If the farmer continues to use the same single herbicide program for consecutive years, eventually these escaped weeds will build up a larger and larger portion of the field population – or natural selection. The second method of developing weed resistance is through cross breeding similar to what seed companies use to develop traits. This occurs when plants within a weed population have different levels of “tolerance” to an herbicide MOA. When farmers use low or reduced rates of the herbicide, these tolerant plants can survive (escape) and cross breed to potentially develop a stronger trait in the next generation. If this pattern continues, this cross breeding will develop a stronger trait of resistance in each subsequent generation, ultimately developing a population of resistant weeds. This is how Shattercane developed resistance to reduced rates of the ALS herbicides. It is important to note that not all weeds have the ability to develop resistance, and not every herbicide MOA will develop resistant weeds equally. Herbicides with very specific sites of activity, like the ALS/AHAS herbicides, tend to have a greater likelihood of resistance selection. The more specific the herbicide site of activity, the higher the probability that a weed can bypass that herbicide’s mode of action. By contrast, herbicides with a very complex MOA such as the chloroacetamides (i.e. Dual) have only two species that have selected for resistance in over 25 years of use. Farmers that are at the greatest risks for developing resistance are those that:
- Use the same herbicide MOA continuously and exclusively (alone)
- Continuously plant the same crop i.e.. Corn on corn
- Use herbicides that have very specific sites of activity
- Have high population of weeds that have shown the potential of developing resistant biotypes, such as kochia, waterhemp, pigweed, lambsquarter, etc.
- Use reduced or below label use rates targeting 80-90% control levels
- Multiple treatments of the same herbicide over and over again
- Use full label use rates of herbicides, even in a tank mix
- Treat weeds early within timing, smaller weeds result in fewer “escapes”
- Prevent weeds from flowering or going to seed
- Use tank mix treatments with multiple modes of action on tough weeds
- Rotate MOA’s between sequential treatments to break up cycles
- Use cultural controls such as tillage or crop rotations to break up cycles
Weed resistance is a growing treat to American agriculture. As fewer new herbicides are developed, there is an increased need to manage the tools that we have. The increased adoption of GMO crops puts increased weed resistance pressures on a select group of herbicides, significantly reducing their long term input value. By adopting the simple herbicide resistance strategies above, farmers can help prolong the use of these valuable tools. A good resistant strategy can incorporate several herbicide groups including GMO technology into a long term sustainable system. Use each herbicide where it provides the greatest value while using sequential or tank mixes to improve control. Incorporating a resistance strategy can lead to improved performance and value, otherwise “If you abuse it, you will lose it!”
- Fertilizer Guidelines
Alfalfa .. good stand .. 100 pounds of "N" per acre Soybeans .. 40 pounds of "N" per acre Alfalfa .. average stand .. 50 pounds of "N" per acre Other Beans .. 25 pounds of "N" per acre Alfalfa .. poor stand .. 0 pounds of "N" per acre Clovers .. 75 pounds of "N" per acre Estimated amount of Nitrogen available from manure application:
Beef Feedlot .. 5 pounds of "N" per ton Swine .. 8 pounds of "N" per ton Dairy .. 8 pounds of "N" per ton Slurry .. 17 pounds of "N" per 1000 gallons Poultry .. 15 pounds of "N" per ton Figuring Nitrogen need for corn:
Factors to consider when figuring Nitrogen need for corn:
- Corn nitrogen need (factor) is 1.33 pounds of "N" per bushel goal. **
- Subsoil factor 0.3
- Surface-soil ppm (parts per million) .. Surface soil depth is usually to 8 inches.
- Sub-soil depth ppm .. Usually up to 3 foot depth. Note if sub-soil ppm is unknown, as a rule of thumb use 5 ppm for fine textured soils and 2 ppm for sandy soils.
- Nitrogen that may be available from other sources after soil test was taken such as manure or other crop grown.
- The nitrogen requirement for corn is figured by (1) multiplying the crop yield goal by nitrogen requirement, 1.33 ** .
- Calculate the amount of Nitrogen available in the surface-soil by multiplying the ppm from the soil test by both the subsoil factor (0.3), and the soil depth in inches at which the soil samples were taken.
- Calculate the Nitrogen available in the sub-soil by multiplying the ppm from your soil test, (or use the 5 ppm or 2 ppm factors mentioned above if no sub-soil test was made) by both the subsoil factor (0.3) and the soil depth in inches at which the sub-soil test was taken.
-
Nitrogen need is then calculated by taking the corn Nitrogen requirement figure and:
subtracting the Nitrogen available in the surface-soil, and
subtracting the Nitrogen available in the sub-soil, and also
subtracting the Nitrogen available in the soil from other crops or manure applications.
** (NOTE: Some researchers feel if adequate nitrogen carryover is in the first three feet of soil, then .8# of added N is the figure to use for each bushel of your yield goal)
PHOSPHORUS …. (P2O5)
Each soil test range is an estimate of "sufficiency". Sufficiency is the range of possible yield as determined by the ppm level. The percent sufficiency ranges for phosphorus soil tests are as follows:Soil Test, Phosphorus ppm % Sufficiency (% of expected standard yield 0 - 5 ppm 25% - 50% of standard yield could be expected 6 - 12 ppm 45% - 80% of standard yield could be expected 13 - 25 ppm 70% - 95% of standard yield could be expected 26 - 50 ppm 90% - 100% of standard yield could be expected 51+ ppm 100% of standard yield could be expected Soil Phosphorus Level, ppm - Estimating Final Grain Yield in Corn
- Alfalfa Planting Tips
If you are planning to seed alfalfa this spring, you most likely have most of your plans made. You have chosen the field, conducted the necessary soil tests, selected an alfalfa variety, and finalized those last-minute planting arrangements. Most of you are now at the stage where you are waiting for the weather to cooperate so that you can seed or drill alfalfa. As you wait for the weather to cooperate, check over your seeding plans and see how they compare with some basic guidelines, as recommended by Warren Thompson, a national forage specialist.
Choose fields with well-drained soil. Thompson suggests that soils drain well internally and do not puddle or “pond”. He discourages the use of soils with a hardpan near (or shallower than) three feet.
Conduct soil tests. Soil pH should be six and a half or above. If lower, Thompson says apply lime, but save the field for another planting. “It takes a minimum of six to eight months to correct or partially correct a pH problem on “open” soils, and around twelve to eighteen months to correct on ‘heavier’ soils,” he says. “This is especially true if you need to elevate the level one full point or more.” (Add phosphorus and potassium as described by soil test results.)
Select an alfalfa variety. Take time to research the numerous varieties available from Hoegemeyer Hybrid’s/Target Seed’s line-up. Pay attention to dormancy and disease resistance ratings. Consider whether you are going to hay it or graze it. Ask questions and look at research data. Thompson says this is a very critical step in the overall planting process. “If you get a good stand, the price of seed represents only about five to seven percent of the total stand establishment cost,” he says. “But, if the stand is poor, or the variety you choose is unproductive, those percentages increase in direct proportion to decreased yields.”
Finalize planting arrangements. Decide whether conventional tillage or no-till is best for your growing situation. “More farmers each year are seeding no-till alfalfa,” says Thompson. “But, it’s very important that growers follow proven no-till seeding recommendations. Don’t take any shortcuts.”
Head for the field. Thompson says you can begin seeding as soon as the frost is out of the ground and you can get into the field. He cautions that precise placement of alfalfa seed is the last crucial step. “More stands of alfalfa are lost during seeding than at any other time in the history of the field,” he says. “Don’t bury the seed! The ideal seed depth in most soils is one-quarter to one-half inch. Deeper than this and you can kiss the stand goodbye.” Thompson adds that some sandy soils may require deeper placement. In addition to Warren Thompson’s statements, make sure that your newly established seed has good seed-to-soil contact.
Many alfalfa seedings could be greatly enhanced if theseeding is in a firm seedbed with good seed-to-soil contact (the fewer air pockets, the better). If the seedbed is not firm, maybe you should be prepared to pack the soil after you drilled or seeded the new alfalfa field. It could make a difference between seeding success or failure.
What about enhancing thinning alfalfa stands? It’s a sad thing, but alfalfa stands don’t last forever. Ironically, due to autotoxicity, you can’t even add new alfalfa to old alfalfa, and you can’t follow alfalfa with alfalfa. That’s why it’s important to evaluate your current alfalfa stands to determine the best time to over-drill with other crops, or to decide if it's time to let the field rest with a crop rotation. Warren Thompson, in conjunction with Dr. Jim Moutray, offers the following guidelines:
If your alfalfa stand drops below sixty percent, you should consider over-drilling with orchard grass either in the fall or early spring. Use a no-till drill to seed at about four to six pounds of orchard grass per acre, and make sure the orchard grass seed is actually covered by soil. Another option is to over-seed with red clover at about six to eight pounds per acre. Whichever option you choose, Thompson says, “Don’t dilly-dally around. The sooner the seed gets in the ground, the better chances are for a satisfactory stand.” If your alfalfa stand is between thirty to forty percent, you should consider over-drilling with both orchard grass and red clover. “This will help fill the holes in the alfalfa and prevent widespread weed encroachment,” says Thompson. “You might also consider moving this field into a grain rotation system to harvest the accumulated nitrogen.” If your stand is below twenty percent, it’s time to plant an entirely different crop. Consider row crops for a couple of years, then you can start over with a new seeding of alfalfa “from scratch”.
Planting Tips:
- A very firm seedbed is required. You should be able to dribble a basketball across the acres you plan to seed!
- Seed-to-soil contact is absolutely necessary.
- Fifteen to twenty pounds per acre is a good seeding rate.
- In clay-loam soils, plant ¼” to ½” deep – no more!
- In sand, plant ½” to ¾” deep.
- In the seeding year, a good stand will have 15 to 25 plants per square feet.
- Alfalfa Stand Analysis
Stand Analysis by Plant Count
This is the conventional way of checking the condition of a stand – Counts must be based on live, HEALTHY plants – do not count plants that have severely damaged roots or develop shoots of different lengths. (Plants per square foot)
Alfalfa Age (yrs) Good Marginal Tear up 1 12+ 8-12 <8 (overseeding may still be an option) 2 8+ 5-6 <5 (autotoxicity limits overseeding success) 3 6+ 4-5 <4 4+ 4+ 3-5 <3 More growers are looking at stem count as a more accurate way of analyzing a stand. Products like TS 4007 have the potential to produce a lot of stems without a high plant count.
Stand Analysis by Stem Count – at 4” – 6” avg. height – count stems over 2” (Stems per square foot)
Alfalfa Age (yrs) Good Marginal Tear up 2 yrs + 55+ 40-55 <40 - Drydown & Standability Making an Ugly Harvest
Dry-down and Standibility in an Ugly Harvest Season
By Dr. Tom Hoegemeyer
As ye sow, so shall ye reap—Galatians 6:7. This year, 2008, has been a VERY unusual year. After many of us were forced to “mud the crop in”, now we are faced with having to “mud it out”. And to make matters worse, it was a cooler than normal spring, summer, and fall. Rather than the crop hitting “blacklayer” in late August or early September, it really didn’t get mature until late September, or even October in many areas. Now we have wet corn in the field.
Before physiological maturity, grain dries down due to a combination of adding more starch to the kernels, transpiring water from the green plant, and from evaporation. After physiological maturity, grain dries primarily from evaporation from the kernel, with some added transpiration in some hybrids. Hybrid characteristics such as ear diameter, husk number, tightness, “staygreen”, and kernel pericarp thickness also affect the rate of moisture loss. This rate of evaporation, as you realize, is a function of temperature, humidity, and wind. To put it simply, warmer, windier, and drier conditions encourage rapid drydown of corn. Most years, the Western Cornbelt has her ideal drying conditions, but cool, humid, rainy weather hampered it this year.
We have several factors working against us concerning rate of dry down. Most corn matured in late September this year, so even with “normal” rain and humidity, the lower temperatures after black layer formation would have slowed drying rates a lot. Second, in most areas we have had over double the “normal” rainfall combined with periods of cloudy, humid, and cool weather—just the opposite of what drives drying. Corn drying in early September will often lose a point or more of moisture per day. Corn drying in the last half of October will loose less than a quarter point per day. Add to that the rain, and having to dry the husk and ear off after each shower before kernel evaporation has a chance. So we find ourselves with wet corn that likely won’t dry much unless we have a period of warmer, sunnier and drier weather.
Stalk quality is also becoming a serious issue. Because corn was (1) behind in maturity and was filling grain September and early October, (2) we had cooler, cloudier weather than normal during grain filling, less photosynthate (sugar) was available to keep the stalk tissues alive and healthy; the plants were madly trying to fill the kernels as we had high yield potential set up. The fungi that cause stalk and root rots are the same ones that deteriorate residue from the previous crop. They don’t strongly attack live tissue, but are very effective in breaking down dead or weaken (poorly nourished) stalks and roots. Plus the growth rate of these fungi is favored by cool, damp weather. Thus, we have the perfect storm for stalk and root rots. Add wind, rain and/or snow, and the potential for problems is large.
My recommendation is that we can’t let a day pass without hitting harvest hard, because corn isn’t going to get significantly drier and it will get harder to harvest every day.
