Reducing Soybean Harvest Losses

Soybean harvest losses result in lost income. Even under the most challenging conditions, soybean harvest losses can be reduced. Careful observation while harvesting will help identify and diagnose problems.

Recommendations for reducing harvest losses 


  • Decrease your ground speed to 2.5–3.0 mph.
  • Plant a range of soybean maturities that are adapted to the area to help prevent all fields from being ready to harvest at the same time.
  • Begin harvesting when the beans in the earliest maturing field first reach 15% to 16% moisture.
  • Complete harvest operations before the beans and pods undergo repeated wetting and drying cycles after they have reached 13% moisture.
  • Avoid harvesting beans that are under 11% moisture when excessive shatter losses are occurring.
  • Under hot and dry conditions, harvest in the morning and in the evening when the pods and beans have picked up some moisture and avoid the heat of the day if shatter losses are excessive.
  • Reduce the speed of the reel in relation to the ground speed if the reel is flailing beans out of the pods. Beans hitting the combine’s windshield is an obvious sign that the reel speed needs to be reduced.


  • Decrease your ground speed to 2.5–3.0 mph.
  • Position the cutter bar as close to the ground as possible.
  • Angle the pickup fingers on the reel back slightly to pull the lodged plants more aggressively to the cutter bar. Reduce the angle of the fingers if the plants are riding over the top of the reel.
  • Move the reel axle forward so that it is 9–12 inches ahead of the cutter bar.
  • Contact the manufacturer for specific recommendations if using an air-assisted reel in lodged soybeans. Moving the reel forward to pick up lodged plants decreases the performance of air-assisted reels. Pivot the drop tubes above the crop if this option is available or remove the entire air manifold and drop tube assembly.
  • Operate the reel as low as necessary to pick up lodged plants without causing them to ride over the top of the reel. Raise the reel if this happens.
  • Install crop lifters on the cutter bar in conditions of severe lodging.
  • When the plants are lodged in one direction, use crop lifters, and travel at a 20- to 25-degree angle to the direction of lodging. Alternatively, harvest the lodged plants traveling opposite to the direction they are leaning.
  • Increase the reel speed relative to the ground speed. It may be challenging to maintain the correct ground and reel speed combination in lodged beans with brittle pods. When ground speed is too fast relative to reel speed, the cutter bar will ride over some plants. When the reel speed is too fast relative to ground speed, the reel may shatter the pods. The reel should run 10% to 25% faster than ground speed under ideal conditions. However, in lodged beans, increase the reel speed incrementally up to a maximum of 50% faster than the ground speed. If the reel is causing pods to shatter, decrease the reel speed to the point when the shattering stops. If the cutter bar rides over lodged plants, decrease your ground speed.

Green stems

  • It is critical to continue harvesting soybeans having green stems even though it requires slower travel speeds and closer attention to cutter bar maintenance, reel speed and position, and threshing adjustments. Waiting for the stems to dry down will lead to large shatter losses.
  • If shatter losses are excessive, consider combining earlier in the morning or later into the evening when the pods have regained some moisture and are less brittle. However, this may increase plugging problems.
  • Reduce your ground speed to 2.5–3.0 mph if necessary. This will reduce shatter losses and plugging at the cutter bar by providing a crisp sideways cut.
  • Harvest at a 20- to 25-degree angle to the rows. This will improve cutter bar performance and provide more even feeding of the crop into the threshing cylinder or rotor. This may be the single most beneficial practice.
  • Draper headers should also reduce plugging problems when harvesting soybeans with green stems as they provide more uniform feeding into the threshing cylinder or rotor.
  • If the cutter bar is plugging, inspect and repair all identified problems. Check that the speed of the knife is correct and that drive mechanisms such as belts are not slipping. Make sure that the knife is in proper register with the guards. Rotate the knife through one complete cycle and make sure that the tips of the knife sections are centered on a guard at the beginning of a cycle and end up centered on a guard at the end of the cycle.
  • Maintain the reel speed at 10–25% faster than the ground speed. Fore and aft reel position is important to reducing slug feeding. Generally, positioning the reel as close to the auger as possible promotes even feeding into the combine.
  • Separating problems result from worn parts on the cylinder or rotor and improper cylinder or rotor clearance or speed settings. The separating equipment must be in good condition to handle soybeans with green or tough stems. Adjustments made to the cylinder or rotor clearance and speed is a balancing act between separating losses and seed damage and split beans. Make one adjustment at a time and inspect the clean grain tank to determine your progress toward minimizing separating losses and maximizing seed quality.

Short plants with low pods

  • Position the cutter bar as close to the ground as possible. Check and adjust the skid shoes on the bottom of the header to lower the cutter bar. You may need to increase the angle of the header to lower the front of the cutter bar (a 3-degree angle is a good starting point). This is a balancing act, as too much of an angle may increase the potential to pick up soil and stones leading to more broken guards and knife sections and cause cut plants and loose beans to build up on the cutter bar. Too flat of an angle may leave unharvested pods on the stubble due to a higher cutting height.
  • Purchase an air-assisted reel, wind system, or an air bar as the air stream produced by this equipment effectively moves short plants and loose beans and pods to the auger or belt. Follow the manufacturers recommendations for positioning the outlets on the drop tubes to maximize performance.
  • Remove the stone guard on the cutter bar if it is preventing short plants, loose beans, and pods from moving to the auger or belt and you do not have an air-assisted reel.
  • Harvest on a slight angle (15 to 20 degrees) in fields planted in 15- or 30-inch rows. This will usually help the short plants feed into the combine more uniformly.
  • The position of the reel will be critical to reducing gathering losses when harvesting short plants. With auger headers, positioning the reel as close to the auger as possible provides the most uniform feeding under most conditions. However, you may need to experiment with fore and aft reel position with very short plants. Lowering the reel is recommended when plants are short to prevent the plants and beans from building up on the cutter bar. The tips of the reel fingers should be about 1.6 cm above the top of the guards or the header floor.
  • Set the speed of the reel about 10–25% faster than the ground speed and adjust as necessary to improve feeding.
  • Set the speed of the belts on draper headers fast enough to assure plant material isn’t building up on the cutter bar.
  • Experiment with your ground speed to find the sweet spot where the cut plants are feeding well into the feeder house and the stubble is cut cleanly and uniformly.
  • Reduce shatter losses by harvesting in the morning or evening when relative humidity is higher.

Check your corn now for stalk strength

As harvest approaches, its time to check our corn plants for stalk integrity.  Time spent tin the field now, may pay huge dividends later this fall.  As stalk tissue becomes compromised below the main ear the stalk may become brittle or weak and be prone to lodging.

There are a number of plant pathogens that can cause stalk rot including, Anthracnose, Bacteria, Charcoal, Diplodia, Fusarium, Gibberella, and Pythium. Some of these stalk rots have very characteristic symptoms that can help identify the specific problem, while others may require laboratory diagnosis (Table 1).  The Purdue Extension Publication Corn Diseases: Stalk Rot has good images to help identify the major stalk rot diseases. ( ).

Check field by using the Push or Pinch Test by evaluating 20 plants in at least five random areas in a field.

  • Pinch Test – grab the stalk somewhere between the lowest two internodes and pinch between your fingers to see if the stalk is strong enough to handle the force – if the stalk collapses, it fails.
  • Push Test – push the stalk to a 30-degree angle – if it pops back up when released, it passes the test, if not it fails.

Threshold: 10% or more of the stalks fail then consider field for early harvesting to avoid risk for lodging.

What can you do in the future – management options will depend on the specific disease (see table 1). Production practices that promote good plant health including balanced fertilization, appropriate plant populations, and good water management can reduce stresses that might predispose corn to stalk rot. In addition, these key management tools can help mitigate future stalk rot issues.

  1. Properly diagnosis the stalk rot pathogen.
  2. Select hybrids with resistance if available.
  3. Crop Rotation – rotating to non-host crop will help reduce stalk rot potential in a field. Note that Charcoal rot and Gibberella stalk rot can infect other rotational crops.
  4. Tillage – burying infected crop residue will encourage more rapid desiccation and help reduces risk of overwintering in crop residue.
  5. Good soil drainage and reduced compaction.
  6. Foliar Fungicides – applying foliar fungicides can help protect crop from foliar diseases that could predispose plant to stalk rot when present, but devoid of foliar disease pressure fungicides applications have not consistently been found to help reduce stalk rot.

Ohio Crop Progress

Source: USDA

Crop maturity accelerated under last week’s warm and dry conditions, according to Ben Torrance, State Statistician, USDA NASS, Ohio Field Office. Topsoil moisture conditions were rated 6 percent very short, 49 percent short, and 45 percent adequate. Statewide, the average temperature for the week ending on September 24 was 63.4 degrees, 2.0 degrees above normal. Weather stations recorded an average of 0.09 inches of precipitation, 0.64 inches below average. There were 6.5 days suitable for fieldwork during the week ending September 24.

Last week’s field activities included hay bailing, manure application, lime spreading, and drainage tile installation. Limited instances of tar spot fungus in corn stands were reported in west-central portions of the State. Seventyseven percent of corn was in or past dent, 40 percent was mature, and 2 percent was harvested. Corn for silage was 59 percent harvested. Fifty-two percent of soybeans were dropping leaves. Corn and soybean condition were 72 and 68 percent good to excellent, respectively. Third cuttings of alfalfa hay and other dry hay were 95 and 80 percent complete, respectively. Fourth cuttings of alfalfa hay were 63 percent complete. Winter wheat was 3 percent planted. Pasture and range condition was rated 56 percent good to excellent, down from the previous week.

Weed management practices: Fall scouting and equipment cleaning


Weed management encompasses more than controlling actively growing weeds. You can be proactive to help prevent the future spread of weeds. Two different management practices are discussed below: fall scouting for weed escapes and equipment cleaning.

Fall scouting can help plan for future control

Weeds that escape control by in-season management practices can cause several problems, including the possibility of reduced harvest efficiency and crop yield. Even if these factors do not justify an herbicide application, it is important to consider the future costs of seeds produced by those escapes – particularly if those escaped weeds produce a lot of seed and/or are herbicide resistant.

Just a few escapes of species such as waterhemp or Palmer amaranth can have a big impact. For example, research conducted in Georgia showed that one female plant in five acres added about two million seeds per acre to the soil. Those seeds can have impacts for many years. It took six years of total palmer amaranth control to deplete the seedbank by 98% in Texas. In some situations, scouting during the weeks leading up to harvest may provide an opportunity to remove these plants by hand to reduce the number of seeds in the soil.

Scouting for weeds at harvest, even if you simply make notes from the combine, is important for planning future weed management.

When scouting, make notes about

  • which weed species are present,
  • where weed escapes are present, and
  • any changes in the size or location of areas with weed escapes.

Some observations might be the result of soil or environmental conditions, while others might suggest problems with the herbicide selection or application equipment. However, some of these escapes might indicate the presence of herbicide-resistant weeds in your field – especially if the same herbicide program has been used for a number of years. Two examples of observations that might indicate herbicide resistance are 1) a growing patch of a particular species, or 2) herbicide failure on a few plants of a single species that is normally controlled.

Stop spreading weed seed during harvest activities

Weeds can spread in a variety of ways, including on farm equipment. As you move harvest equipment from field to field, be aware of the potential to spread weed seed – especially if uncontrolled weeds are known or suspected to be herbicide resistant. Some steps to prevent spreading weeds when moving harvest equipment from one field to another are listed below.

  • Clean new-to-you equipment so someone else’s weeds are not introduced to your farm.
  • If possible, harvest fields with excellent weed control first.
  • Harvest fields where weeds are or might be herbicide resistant last.
  • Harvest around areas with extremely dense weed populations.
  • Slow the combine to ‘self-clean’ between fields.
    • Run the unloading auger empty for a minute or two.
    • Open grain elevator doors, rock trap, and unloading auger sump then run the separator with maximum airflow and suction.
  • Use an air compressor to remove material remaining in the rock trap and grain auger and from the head, feeder house, straw spreader.
  • Take half a day to do a deeper clean when possible.
  • Check fall-tillage equipment between fields.

It is very difficult to completely remove weed seeds from harvest equipment. However, taking a few minutes to reduce the number of seeds on your harvest equipment may save time and money in the future.

Estimating soybean yield

Soybeans are beginning to change color (mature) which has many of us thinking about yield potential.  To estimate soybean yield, four yield components need to be considered: plants per acre, pods per plant, seeds per pod, and seeds per pound (seed size).  A printable worksheet to estimate soybean yield can be found by clicking here.

Proceed with caution when estimating soybean yield. It is difficult to accurately predict soybean yield because of plant-to-plant variability and fall weather conditions can influence seed size.  Estimates are more accurate later in the growing season and on uniform stands.

To estimate soybean yield:

Step 1: To calculate plants per acre, count the number of pod-bearing plants in 1/1,000th of an acre.  In 7.5-inch row spacing, count the number of plants in 69 feet, 8 inches of row.  In 15-inch row spacing, count the number of plants in 34 feet, 10 inches of row.  In 30-inch row spacing, count the number of plants in 17 feet, 5 inches of row.

Step 2: To estimate pods per plant, count the number of pods (containing one or more seeds) from 10 plants selected at random.  Divide the total number of pods by 10 to get the average number of pods per plant.

Step 3: To estimate the number of seeds per pod, count the number of seeds from 10 pods selected at random.  Generally, the number of seeds per pod is 2.5, but this number can be less in stressful environmental conditions.  Divide the total number of seeds by 10 to get the average number of seeds per pod.

Step 4: To estimate the number of seeds per pound (seed size), assume that there are 3,000 seeds per pound.  If the soybean plants experienced stress, seed size will be reduced, and it will take more seeds to make one pound.  Use a seed size estimate of 3,500 seeds per pound if smaller seeds are expected because of late season stress.

Using the above estimates, the following formula can be used to estimate soybean yield in bushels per acre:  bushels per acre = [(plants/1,000th acre) x (pods/plant) x (seeds/pod)] ÷ [(seeds/pound) x 0.06]

 Example:110 plants per 1/1,000th acre, 65 pods per plant, 2.5 seeds per pod, 3,000 seeds per pound. [110 * 42 * 2.5] / [3,000 * 0.06] = 64.2 bushel per acre.

Estimating corn yields

According to the latest Ohio Crop Weather Report 90% of the Ohio corn crop is in the dough stage, 3 percentage points ahead of the 5-year average.  40% of the crop is in the dent stage 10% below the 5 year average.

This time of year many of us begin to think about our potential corn yield.  The most popular yield estimator is the  THE YIELD COMPONENT METHOD.  This procedure was developed by the Agricultural Engineering Department at the University of Illinois.  The yield component method involves use of a numerical constant for kernel weight which is figured into an equation in order to calculate grain yield. This numerical constant is sometimes referred to as a “fudge‑factor” since it is based on a predetermined average kernel weight. Since weight per kernel will vary depending on hybrid and environment, the yield component method should be used only to estimate relative grain yields, i.e. “ballpark” grain yields. When below normal rainfall occurs during grain fill (resulting in low kernel weights), the yield component method will OVERESTIMATE yields. In a year with good grain fill conditions (resulting in high kernel weights) the method will underestimate grain yields.

In the past, the YIELD COMPONENT METHOD equation used a “fudge factor” of 90 (as the average value for kernel weight, expressed as 90,000 kernels per 56 lb bushel), but kernel size has increased as hybrids have improved over the years.  Assuming no stress during grain fill, a “fudge factor” of 80 to 85 (85,000 kernels per 56 lb bushel) is a more realistic value to use in the yield estimation equation today.

Step 1. Count the number of harvestable ears in a length of row equivalent to 1/1000th acre. For 30‑inch rows, this would be 17 ft. 5 in.

Step 2. On every fifth ear, count the number of kernel rows per ear and determine the average.

Step 3. On each of these ears count the number of kernels per row and determine the average. (Do not count kernels on either the butt or tip of the ear that are less than half the size of normal size kernels.)

Step 4. Yield (bushels per acre) equals (ear #) x (avg. row #) x (avg. kernel #) divided by 85.

Step 5. Repeat the procedure for at least four additional sites across the field. Keep in mind that uniformity of plant development affects the accuracy of  the estimation technique.

The more variable crop development is across a field, the greater the number of samples that should be taken to estimate yield for the field.

Example: You are evaluating a field with 30‑inch rows. You counted 32 ears (per 17′ 5″ = row section). Sampling every fifth ear resulted in an average row number of 16 and an average number of kernels per row of 33. The estimated yield for that site in the field would be (32 x 16 x 33) divided by 85, which equals 199 bu/acre.

Field Observations Thru July 14


2nd cutting is well underway.  Potato leafhoppers are very active. If you haven’t cut yet, continue to monitor, where damage is increasing, cut as soon as weather permits.

Click here for alfalfa insect scouting calendar

Click here for more information on Potato Leafhopper


Our corn growth varies greatly throughout the county. Some fields are beginning to tassel and some field are at V8.

V12 to V13 – Six weeks after the plant emerges, V12 begins. Moisture or nutrient deficiencies may reduce the potential number of seeds, as well as the ear size, seriously. These two components of yield have key development during the period from V10 to V17. The length of time for the plant to develop through these stages affects harvestable yield.

Early maturity hybrids normally progress through these stages in less time and have smaller ears than later hybrids. Higher plant populations are needed for earlier hybrids to produce grain yield similar to normal-maturity hybrids in the adapted region. Cultivation of plants at this time will destroy some of the plant roots. Brace roots are developing from the fifth node and the first above-ground node.

V14 to V15 – Seven weeks after the plant emerges, V14 begins. The corn plant at V15 is only 12 to 15 days (around one to five V stages) away from R1 (silking). This vegetative stage is the most critical period of seed yield determination. The number of ovules that develop silks, and thus the number of kernels, is being determined. Any nutrient or moisture deficiency or injury (such as hail or insects) may seriously reduce the number of kernels that develop.

The tassel is near full size but not visible from the top of the leaf sheaths. Silks are just beginning to grow from the upper ears. Upper-ear shoot development has surpassed that of lower ear shoots. A new leaf stage can occur every one to two days.

Brace roots from the sixth leaf node are developing, and the permanent roots have continued to elongate and proliferate, eventually reaching a depth of about 5 to 8 feet and spreading several feet in all directions. In some hybrids, brace roots also will develop from the eighth and ninth leaf nodes or even higher. Some corn plants in North Dakota may only develop 16 leaves.

Critical corn growth stages

Table 5. Postemergence Herbicides in Corn – Grasses

Table 6. Postemergence Herbicides in Corn – Broadleaves


Soybeans are starting to look a little bit better, however, there are still a lot of “yellow” beans throughout the county.  Two possible reasons are Yellow Flash and Soybean Cyst Nematode.  Other possibilities are seedling diseases and water-logged roots, more information on these topics next week.

After planting, the second biggest challenge we face is timely weed control.  If you haven’t already made a postemergence application, it might be time to check your fields.  Most beans (and weeds) are at stage that might warrant an application.  The links below will contain OSU Herbicide rating for postemergence applications.

Soybean Postemergence Weed Control – Grasses

Soybean Postemergence Weed Control – Broadleaves

Soybean Growth & Development – R1: Beginning Bloom


  • Open flower at any node on the main stem
  • Flowering begins at 3rd to 6th node (V6 to V10 stage)
  • Flowering period is 3 to 4 weeks
    –Begins ~6 to 8 weeks after emergence
    – Peaks R2 to R3; ends ~R5
  • Vertical root growth rates increase rapidly
    – As much as 1.3 to 3.2 in/day


Wheat harvest has come to an end and most of the straw is in the barn.  From what I hear, wheat yields were pretty good with little to no disease issues.

If you removed the straw, remember to account for the additional fertilizer removal when planning for fertilizer needs next year.  Read more here.

Double crop beans have been, or are being planted now.  Click here for the Double Crop Soybean Production Guidelines from Dr. Laura Lindsey.

Misc. – Something you don’t see everyday.

I can honestly say that I have never seen one of these before! Click on the picture to see the video. If you know what it is, put your answer in the comment section.  Be sure to check back next week for the answer!

… AND THE ANSWER IS – Horsehair Worm

County Rainfall Update

Corn Water Requirements

Soybean Water Requirements

Nutrient Value of Wheat Straw

Wheat harvest is wrapping up and a lot of straw has been bailed this week.  If you are bailing straw, remember to account for the additional fertilizer removal when planning for fertilizer needs next year. Each bushel of wheat removes .5 lbs of P2O5 and .25 lbs K2O.  So 100 bushel/acre of wheat removes 50 lbs of P2O5 and 25 lbs K2O.  The following article summarizes the value of the additional nutrients removed in the straw.

Before removing straw from the field, it is important to understand the nutrient value. Though we have seen some softening of the 2022 fertilizer prices, P and K fertilizer prices remain higher than normal. The nutrient value of wheat straw is influenced by several factors including weather, variety, and cultural practices. Thus, the most accurate values require sending a sample of the straw to an analytical laboratory. However, “book values” can be used to estimate the nutrient value of wheat straw. In previous newsletters, we reported that typically a ton of wheat straw contains approximately 11 pounds of N, 3.7 pounds of P2O5, and 29 pounds of K2O. According to June 2023 fertilizer prices (Source: DTN Fertilizer Price Index: Ohio) and nutrient removal “book values”, one ton of wheat straw would remove N, P, K valuing approximately $25.13 ($16.55 of P2O5 & K2O).

Although N adds value, we do not give it an economic value in the form of fertilizer (as seen in Table 1). Within straw, N is in an organic form and will not immediately be available for plant uptake. The organic-N will need to be converted by microorganisms to ammonium-N (an inorganic form) before it is available for plant uptake – a process called mineralization.  The rate of which mineralization occurs depends on the amount of carbon (C) and N in the straw (C:N ratio). The USDA reports a C:N ratio of 80:1 for wheat straw which means there are 80 units of C for every unit of N. Mineralization rapidly occurs when the C:N ratio is ≤ 20:1. At a C:N ratio of 80:1, mineralization will be much slower. (For comparison, corn stover is reported to have a C:N ratio of 57:1.) Rate of mineralization is also influenced by soil moisture and temperature. Since mineralization is a microbial-driven process, mineralization will be slowed (halted) in the winter when temperatures are cold. Thus, no N credit (i.e., value) is given for wheat straw since it is not known when the N will mineralize and become available to the following crop.

In addition to N, removal of straw does lower soil K levels. If straw is removed after heavy rainfall, some of the K may have leached out of the straw, lowering the nutrient value. However, a soil test should be done to accurately estimate nutrient availability for future crops. Besides providing nutrients, straw has value as organic matter, but it is difficult to determine the dollar value for it.

Potential for Nitrate Problems in Drought Stressed Corn

Source: Peter Thomison, Laura Lindsey, OSU

Have very dry soil conditions increase the potential for toxic levels of nitrates in corn harvested for silage? Nitrates absorbed from the soil by plant roots are normally incorporated into plant tissue as amino acids, proteins, and other nitrogenous compounds. Thus, the concentration of nitrate in the plant is usually low. The primary site for converting nitrates to these products is in the growing leaves. Under unfavorable growing conditions, especially drought, this conversion process is slowed, causing nitrate to accumulate in the stalks, stems, and other conductive tissue. The highest concentration of nitrates is in the lower part of the stalk or stem. For example, the bulk of the nitrate in a drought-stricken corn plant can be found in the bottom third of the stalk. If moisture conditions improve, the conversion process accelerates and within a few days, nitrate levels in the plant return to normal.

The highest levels of nitrate accumulate when drought occurs after a period of heavy nitrate uptake by the corn plant. Heavy nitrate uptake begins at the V6 growth stage and continues through the silking stage. Therefore, a drought during or immediately after pollination is often associated with the highest accumulation of nitrates. Extended drought prior to pollination is not necessarily a prelude to high accumulations of nitrate. The resumption of normal plant growth from heavy rainfall will reduce nitrate accumulation in corn plants, and harvest should be delayed for at least 1 to 2 weeks after the rainfall. Not all drought conditions cause high nitrate levels in plant. If the soil nitrate supply is low in the dry soil surface, plant roots will not absorb nitrates. Some soil moisture is necessary for absorption and accumulation of the nitrates.

If growers want to salvage part of their drought damaged corn crop as silage, it’s best to delay harvest to maximize grain filling, if ears have formed. Even though leaves may be dying, the stalk and ear often have enough extra water for good keep. Kernels will continue to fill and the increases in dry matter will more than compensate for leaf loss unless plants are actually dying or dead. Moreover, if nitrate levels are high or questionable, they will decrease as the plant gets older and nitrates are converted to proteins in the ear.

Making Corn Silage in Dry Conditions

Source: Bill Weiss, OSU

The primary goal of making corn silage is to preserve as many nutrients in the corn plant as possible, to produce a feed that is acceptable to cows, and to minimize any risks associated with feeding the silage.  The following are important considerations for making corn silage when growing conditions have been dry.

Chop at the correct dry matter concentration (Editor’s note: see accompanying article “Corn Silage Harvest Timing”). Drought-stressed corn plants are often much wetter than they appear, even if the lower plant leaves are brown and dried up.  Before starting chopping, sample some plants (cut at the same height as they will be with the harvester) and either analyze DM using a Koster tester or microwave or send to a commercial lab (turn-around time may be a few days if you send it to a lab).  If the plants are too wet, delay chopping until the desired plant DM is reached.  The plant may continue to accumulate DM (increase yield), and you will not suffer increased fermentation losses caused by ensiling corn that is too wet.

Use a proven inoculant.  When silage is worth upwards of $80/ton (35% DM) reducing shrink by 2 percentage units has a value of about $2/ton. Homolactic inoculants (these are the ‘standard silage inoculants’) produce lactic acid which reduces fermentation losses but sometimes can increase spoilage during feedout. The buchneri inoculants increase acetic acid which slightly increases fermentation losses but greatly reduce spoilage during feedout.  Severely drought-stressed corn can have a high concentration of sugars because the plant is not depositing starch into the kernels.  High sugar concentrations can increase spoilage at feed out because it is food source for yeasts and molds.  Use of a good (from a reputable company with research showing efficacy) buchneri inoculant may be especially cost-effective with drought-stressed corn.

Check for nitrates.  Drought-stressed corn plants can accumulate nitrates which are toxic (as in fatal) to ruminants.  Silage from drought-stressed fields should be tested before it is fed.  Ideally, corn plants should be sampled and assayed for nitrates prior to chopping (most labs offer very rapid turn-around times for a nitrate assay).  If values are high, raising the cutting height will reduce nitrate concentrations in the silage because the bottom of the stalk usually has the highest nitrate concentrations.  Because forage likely will be very limited this coming year, do not raise the cutting height unless necessary to reduce nitrate concentrations.  Nitrate concentrations are often reduced during silage fermentation so that high nitrates in fresh corn plants may end up as acceptable concentrations in the fermented corn silage.  Silage with more than 1.5% nitrate (0.35% nitrate-N) has a high risk of causing nitrate toxicity in cattle.  See the following University of Wisconsin-Extension fact sheet for more details on nitrate toxicity:

Chop at correct particle length.  Do not chop too finely so that the effective fiber concentration of corn silage is reduced.  If the corn plants have limited ear development, fine chopping is not needed for good starch digestibility.  Generally, a theoretical length of cut (TLC) of about ½ inch is acceptable (longer with kernel processing and BMR silage) but this varies greatly between choppers and crop moisture concentration.  If using a Penn State particle size sieve, aim for 5 to 10% on the top screen.

Use a kernel processor.  Kernel processed corn silage tends to pack more densely than unprocessed corn silage which may help increase aerobic stability.  Kernel processing will also increase starch digestibility by breaking the kernel.  Poor starch digestibility is a major problem with dry, mature corn silage.

Reduce Shrink. Fill quickly, pack adequately, cover, and seal the silo as soon as you are done filling.  Practicing good silage-making techniques can reduce shrink by more than 5 percentage units, which can be worth more than $4/ton of corn silage (35% DM).