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Out Croppings: Important crop news from the field!

Sidedressing Your Corn: How Much is the Right Amount?

Posted: June 25th, 2015 by outcropn

Recommended nitrogen rates for corn based on the Pre-sidedress Soil Nitrate Test (PSNT).

Recommended nitrogen rates for corn based on the Pre-sidedress Soil Nitrate Test (PSNT).

Before you sidedress your corn, we recommend doing the Vermont Pre-Sidedress Nitrate Test (PSNT). The PSNT measures nitrate, the main form of nitrogen (N) taken up by plants and an indicator of N available to the crop for the remainder of the season. The PSNT should be taken right before you sidedress, so you can identify if there is enough, too much or too little soil-nitrate for the crop to reach your yield goals. Applying too much fertilizer wastes money and can lead to environmental damage by nitrate leaching into waterways. Applying too little can decrease yields.

How to Use the PSNT

Sample fields when corn plants are 8 to 12 inches tall, taking 15 to 20 soil cores per field at a depth of 12 inches. Avoid sampling close to where you had banded fertilizer near the row. Take the samples in a zig-zag pattern all over the field so you get a good representation of the area. Do not specifically choose ‘nice’ or ‘bad’ spots – be random. Mix the soil cores together in a clean plastic bucket and place a few handfuls of the soil in a paper bag. For more tips on how to soil sample, check out this link from the UVM Agricultural and Environmental Testing Lab.

When in the field, keep the samples cool in the shade or in a cooler. The main reason to keep the samples cool is to prevent microbes that are active at warmer temperatures from further breaking down organic nitrogen, which would give you less accurate test results. Ideally, get the sample immediately to the laboratory for analysis. If this is not possible, dry the sample by spreading out the soil on a paper bag in the sun so it dries quickly. Or, put the sample in a glass dish in a very low temperature oven, less than 150 degrees Fahrenheit until dry (2 to 4 hours should be fine). If drying is not possible, put your samples in the refrigerator.

See below for a helpful chart to interpret your PSNT results. If the PSNT is 25 ppm or higher, there is little or no yield increase from applying more nitrogen (Jokela, 2008). The chart comes from the extension publication, Nutrient Recommendations for Field Crops in Vermont, where you can find more information on soil and nutrient management.

For more information, contact the UVM Agricultural and Environmental Testing Lab at 802-656-3030, call our office 802-524-6501, or email us at cropsoilvt@gmail.com.

Recent Rain Creates Stress on Crops

Posted: June 16th, 2015 by outcropn

Recent intense rainfall events have caused flooding, ponding, and soil saturation in many of our corn
and hay fields. What are the prospects for these crops?

Corn Fields

Corn plants can turn pale green to yellow because they have not been able to absorb enough nitrogen.

Corn plants can turn pale green to yellow because they have not been able to absorb enough nitrogen.

Beautiful and dry spring weather allowed most folks to get corn planted in a timely fashion. We’ve seen corn around the state that is just about knee high and ready for nitrogen topdress! The recent rain, however, has caused some fields to become flooded, ponded or saturated with water. Flooded or ponded soil can create risks for corn. Soil oxygen becomes depleted after about 48 hours of soil saturation. Without oxygen, corn cannot perform critical life functions (i.e. nutrient uptake, root growth inhibited). Corn that is at the 5th leaf stage and younger still has its growing point below ground and it is directly subject to the stress of oxygen depleted conditions. The likelihood of crop injury is less where the flooded and ponded conditions last less than 24 hours. To confirm plant survival, check the color of the growing point and look for new leaf growth 4 to 7 days (with 70 degree weather) after the water drains from the field. Healthy growing points will be firm and yellowish white, not mushy and discolored.

Even if ponding and saturated soil do not kill the plant outright, it can have a negative impact on the crop performance. Excess moisture can retard root growth and plants may become more susceptible to drought stress later in life. Saturated soils can also result in significant losses of nitrogen through denitrification and also leaching. A pre-sidedress nitrate test taken just prior to nitrogen topdress can help you understand how much additional nitrogen will be needed to growth a high yielding corn crop.

Hay and Pasture Fields

Forage plants (other than perhaps wet site-tolerant reed canary grass) can survive for several weeks in saturated soils, but the lack of oxygen in the root zone will adversely affect their growth. These plants do not take up soil nutrients normally, an increasing part of the root system deteriorates, and legumes cease “fixing” nitrogen. They appear stunted and yellowish-green in color. If the soils drain quickly, plants begin to recover.

Flooded forages may contain fine silt, fungus spores, bacteria that are bad for you and your animal’s health. Forage that has been flooded with silt and debris can cause health problems, production problems, and/or reproduction problems in livestock. To be safe, avoid making silage out of it. However, if you do, keep it separate from the rest of your unflooded silage. It may spoil and it could contaminate adjacent silage. If you ensile these flooded crops, you may find that once the silo is opened, they spoil faster than other silage. Generally, you should avoid feeding this material if possible. However, if you haven’t already done it, try to get this standing material off the field as soon as possible to encourage regrowth. If hay fields were flooded, remember to wear a dust mask when harvesting. Grazing animals can be exposed to clostridial organisms that can lead to some serious diseases. The safest approach would be to clip the contaminated pastures and then wait to graze the regrowth. But don’t graze it too closely – avoid letting your livestock get down into the old dead material. Watch your livestock closely. If any of you animals appear sick, call your vet immediately.

If you have any questions, please give our office a call or email cropsoilvt@gmail.com.

Be on the Lookout for Loose Smut!

Posted: June 9th, 2015 by outcropn

As winter grloosesmutains start to head out and flower, it’s time to start scouting your fields for Loose smut (Ustilago nuda, U. avenae, U. tritici). Loose smut is found in winter and spring spelt, barley, and wheat, as well as oats. Spelt and barley are particularly susceptible to infection. Loose smut is one of the easiest grain diseases to spot in the field. During spike or head emergence, diseased heads emerge slightly earlier than healthy ones and appear as a mass of dark brown spores covered with paper-like membrane. This membrane tears easily as healthy plants begin to flower, and windblown spores infect the embryos of developing seed. After the fungus invades the grain seed embryo, it remains dormant until the seed is planted and germinates. Infected plants appear to be normal, but develop smutted heads.

Planting contaminated seed, especially in organic systems, can exponentially increase grain infection rates, resulting in yield reductions; 100% of the smutted heads are lost. Eating Loose smut infected grain poses no harmful health effects and doesn’t appear to impact baking quality.


  • If you find Loose smut in your fields, don’t save the seed.
  • Plant certified or otherwise high-quality, disease-free seed.
  • Plant resistant varieties.
  • Infected seed can be treated with various systemic fungicides in conventional systems.
  • In organic systems, hot water seed treatment can be used to rid infected seed of the Loose smut fungus.

If you have questions about Loose smut or any other plant disease, the University of Vermont Plant Diagnostic Laboratory can help. Click on this link for details on submitting a sample for identification – http://pss.uvm.edu/pd/pdc/pdf/pdcform.pdf

Now, it has started raining…

Posted: June 2nd, 2015 by outcropn

After a pretty dry Spring, the rain finally came and has pushed back a lot of our schedules. Hopefully you were able to make the first cut off your hay field, before all of this rain came in. If you haven’t, harvest will be pushed back and by that time the hay will lose up to ½ point of protein per day from its optimum harvest date. You may want to consider using this cut for dry cow and heifer feed. If you were able to make the first cut, wait to put manure down until the ground is no longer saturated with water. Vermont’s 590 Standard requires that manure not be applied onto saturated ground since there is an increased risk of runoff into waterways. Also, for those of us who were planning to put no-till corn in the ground after the first cut of hay, we’ll have to wait until the ground has dried. Muddin’ in seed will not work on most soils as it is very difficult to close the slot when the soil is wet and sticky.

For corn that has already emerged, now is a good time to scout for weeds. This rainy period may create a flush of weeds if herbicides with residuals were not applied. As for late planted corn, it would be worth it to check on germination rates as it has been wet and cool lately. Be sure to use the appropriate herbicide if you are planning to put cover crop in the ground in July. Some residual herbicides will have a lasting effect until August. UVM Extension has obtained a document, which makes good recommendations and is worth checking out. Click on this link to view the document “Improving the Success of Interseeding Cover Crops in Corn”. If you have questions, feel free to contact us at 802.524.6501.

Just Drill It

Posted: May 12th, 2015 by outcropn

Haybuster no-till drill.

Haybuster no-till drill.

Now that spring is in full swing, corn is going in the ground and farmers are evaluating their pastures and meadowlands.  Rumor has it that winter kill was substantial this past winter, and now is the time to mend your pastures and meadows.  UVM Extension has 4 drills available for rent throughout the Champlain Valley.  Currently, the Northwest Crops and Soils Program has a 10 ft Sunflower no-till drill and a 15 ft John Deere no-till drill.  Both of these drills are available for use for a fee of $10 per acre to help offset repairs (contact Jeff Sanders at 802-524-6501 to use).  The Middlebury Extension office and the Champlain Valley Crops, Soil, and Pasture team has two 10 ft Haybuster no-till drills available for use (contact Jeff Carter at 802-388-4969 to use).  If you call the UVM Extension Offices, we can help get the drills to you and instruct you on how to use them most effectively.

When using a drill, there are several important considerations to keep in mind.

  • Pay close attention to your seed mixes. When getting seed custom blended or if purchasing pre-mixed seed, you need to be mindful of seed size. Mixing clover and alfalfa with orchard grass may cause problems in the small seed boxes. Light bulky seeds like orchard or brome grass can be problematic in the seed boxes with the smaller seeds. Try to keep seeds of similar sizes and weights together for a more consistent flow through the drill and more accurate seeding rates.
  • The drills need to be calibrated. It is recommended that you put in a known amount of seed and cover a known area to check your rate. If you dump all of your seed in and only use the chart on the inside of the lid of the drill, you will probably not be happy with the results. The charts are only approximations and once you start putting multiple species of seeds together, you need to check the seed rate manually.
  • Keep track of seeding depth. Spring seeding forage seed only needs to be planted ¼ inch deep to be effective. When checking out the drill, make sure the seed depth is where you need it. The best way to do this is to drop the drill in the field and drive forward about 10 feet. Then get off and carefully investigate the seed trench and check the depth with a ruler. This becomes critical when using no-till drills in ground that has been conventionally tilled. These no-till drills are designed to plant on hard soils. They are heavy and when used in worked ground, all the settings need to be backed off to allow the seeder to “float” as much as possible on top of the soil.
  • When overseeding into a poor stand to rejuvenate it, a seeding rate of 8-10 pounds of seed should be drilled depending on seed varieties selected.
  • When drilling a clearstand or filling in winter kill spots in a field, a seeding rate of 12-18 pounds is recommended, again depending on what you are seeding. Please consult with your seed salesperson, crop consultant, or Extension personnel for more information regarding seeding rates.
  • Don’t plant when it is too wet. The key to drilling seed is getting good soil-to-seed contact and wet muddy soils will result in poor stands.
  • Using GPS. If you have access to a GPS unit, try to get it put into the tractor before you drill. It can be difficult to see where you have been and none of the drills have marker arms.

If you have questions or would like more information about drilling, please contact Jeff or Heather at the St. Albans UVM Extension Office at 802-524-6501.

Please Die Rye

Posted: May 8th, 2015 by outcropn

Over these past summer-like days, undoubtedly you’ve seen some rye growth! So now is definitely the time to be thinking about termination.

Killing the rye through plow down or herbicides are your options right now. Incorporating a winter rye cover crop in its vegetative stage will result in the quickest nitrogen release to your corn crop. An early kill can give a 30 to 50 pound nitrogen credit.

When rye reaches the boot stage (right before the head emerges), it may be harder to kill and will be slower to break down. It also may tie up nitrogen and delay its availability to the corn crop.

If you are planning a no-till corn planting, terminate with herbicide immediate after planting –timing is key so be sure planting aligns with a nice stretch of weather. If you are planning to terminate the rye with a roller-crimper, you must wait until the rye is flowering — when the anthers are clearly visible and shedding pollen. If you do not wait until this critical stage, the winter rye will likely “stand back up” shortly following rolling and crimping.

Enjoy the nice weather.

My cover crops are growing

Posted: April 28th, 2015 by outcropn

April is almost over and the wet and cool weather has everyone feeling like they are a little behind in their field work already!! It looks like we have a decent stretch of weather coming through the first few days of May. If you drove by your fields and thought to yourself ‘my cover crops are turning green that’s nice,’ it’s time to check them again. With the recent moisture and now a warming trend in the temperatures, winter rye is getting ready to GROW!!

  • If the crop is at 8 – 10 inches in height and you are not sure of when you can set it back with manure, tillage, or planting in the next 10 days, you need to start thinking of a way to terminate it before it becomes a problem.
  • If you’re planting beans, it will not be a problem. You can routinely no till into standing rye then spray and have a super bean crop.
  • If you are no-tilling corn into standing rye, in most cases as long as you terminate (spray herbicide) immediately after planting it will not be a problem although it may tie up some nitrogen as it begins to decompose (as much as 70# if rye is mature).
  • If you are planning on conventional tillage, you need to watch your cover crop carefully or you will spend considerable time fighting with it in early June trying to get it to lay down enough to plant you corn into.

If you are planning to get out and apply manure, please pay attention to your setbacks and buffers. Work towards tilling the manure in immediately after application as it will retain 50% more nitrogen then leaving it sitting on the surface for a few days (the ammonium nitrogen will volatilize quickly on the surface and be lost to the atmosphere). Its money in your pocket and you have to till it anyway. It will also mitigate runoff concerns on slopes or in case of a major rain event. If you want to test this theory split a field and try immediately working the manure in and waiting. Call UVM Extension and we will do a PSNT test for you and show you the savings in nitrogen.

On another note, UVM Extension will be taking delivery of the Hagie Highboy Seeder this week and we will be making several modifications to it to make it a more precise applicator of cover crop seeds. Please feel free to contact us if you have interest learning more about cover cropping, the highboy machine, or in having us do demonstrations on your farm, 802-524-6501.

Welcome to our Soil Health Updates!

Posted: April 23rd, 2015 by outcropn

Cover crop season seems a ways off as we still have not begun much field work, but one of the keys to successful cover cropping is planning. As part of creating a good plan with lots of options, the University of Vermont Extension Northwest Crops and Soils Program is going to start sharing regular Soil Health Update information on our Out Croppings Blog. This will include information on cover crops, no-till, soil building, improving crops, and more.

We invite you to join our Out Croppings community by signing up to receive weekly updates on what’s going on with soil health, cover cropping, and other things for you to consider. We will bring to you pictures, recommendations about planting and terminating cover crops, equipment profiles, highlight cover crop properties that improve soil health, and other options to help you make the best decisions for your operation in regards to soil health. We will let you know of NRCS, State and other sign-up deadlines, NRCS recommendations, field reports, and herbicide considerations to help you as you explore this emerging cropping system. We will share interesting links to articles and products that you can use to make cover cropping work for your operation.   Please sign-up to receive these weekly updates. You can let us know what information you are looking for, and we will find it for you. Thank you!

We look forward to sharing information with you!  If you have any questions, please contact Susan Brouillette at susan.brouillette@uvm.edu or 802-524-6501.

Evaluating and Managing Alfalfa Stands for Winter Injury

Posted: April 22nd, 2013 by outcropn

Dr. Heather Darby UVM Extension Agronomist


Many conditions occurring in the fall, winter or spring can have an impact on the winter survival or injury of perennial forage stands, particularly alfalfa. Therefore it is important to assess stands early in the spring and explore your options for managing winter injury.

How to Diagnose Winter Injury

First and foremost it is most important to determine if your fields were impacted by the winter weather. The most obvious sign of winter injury are stands that are slow to green up in the spring. If other fields in your area are starting to grow and yours are still brown, those stands should be checked for injury or death. In addition to “slow green-up,” fields with uneven growth patterns may also indicate damage.


The best way to diagnose damage is to examine the plant roots in a suspect field. To do this, walk diagonally across a field and at regular intervals (every 4 to 5 paces) dig up a shovelful of plants (4 to 6 inches deep) and examine their roots. The roots of each plant should be firm and the interior color should be white or cream colored. If the roots are soft and the interior yellow to brownish in color it most likely was winter-killed. winter_kill_alfalfa4For alfalfa, the majority of healthy crown buds should be white or pink and firm throughout the bud. It is important to try and inspect as many plants as possible to determine the percentage of the stand and/or areas of the field that are injured.


Options for Fields Moderately Affected by Winter Injury

Winter-injured stands will require different management practices than healthy stands if they are to stay in production. If winter injury is evident consider the following:

Allow alfalfa plants to mature longer than normal before cutting. This will help the plants rebuild needed energy for future production. For severely-impacted stands, allow plants to go to full bloom before taking a first cut and to the early flowering stage for subsequent harvests. Increasing the cutting height may also help stands recover (Cosgrove and Undersander, 2003). New shoots will be developing at the base of the injured plants and it is important to not remove these shoots, which would result in further detriment. Lastly, do not cut winter-injured stands late in the fall; this will allow them to build up more reserves before winter.

If a significant loss of alfalfa was seen in a predominant grass stand, then you could manage it for grass. This will work best if the grass species are dominated by tall-growing species such as reed canarygrass, orchardgrass, and/or timothy. If the grass is less than 10 inches tall, it may still be economical to apply 50 pounds of nitrogen per acre to boost yield and protein. If the grass stand consists mainly of a lower-yielding forage such as “June” grass (bluegrass) you may want to consider replanting.

If the alfalfa stand was only partially injured (25 to 50 %), interseeding with a quickgerminating forage crop in thin spots could provide additional production (Stauffer, 2009). Interseeding can be done with a grain drill. No-till application into existing sods will provide the best results. In the event a drill is unavailable broadcast seeding is an option but generally results in a less uniform stand. Species that could be considered for interseeding include clover (4-6 lbs/acre), orchardgrass (8-10 lbs/acre) or perennial ryegrass (8-10 lbs/acre). Remember that perennial ryegrass maybe a short-term option since it does not overwinter well in all areas of the Northeast. Alfalfa should not be reseeded into the stand due to autotoxicity issues. When dealing with winter-injured stands, it is particularly important to adequately fertilize and control for weed competition.

Options for Fields Severely Affected by Winter Injury

If your stand was over 50% winterkilled, you may want to consider replanting. Depending on your needs, there are several forage choices.

A small grain/field pea mixture could be a good choice if the forage is needed in early- to mid- summer. Early-planted small grains (60 lb/acre) such as oats, barley, or triticale with the addition of field peas (50 lb/acre) will be ready for harvest between late June and mid-July. Research from the University of Wisconsin has reported yields between 2.5 and 3.0 tons/acre and Relative Forage Quality (RFQ) of approximately 100-125 (Undersander, 2003). Small grain/pea mixes should be harvested when the small grain is at late boot stage.

Corn silage will be the best choice for optimizing full-season forage production. If corn silage is planted by the end of June it will normally outyield most other forages; however you risk lower quality forage. At these later dates (mid-June to early July) you may want to consider planting a summer annual. A few options include sorghum-sudangrass hybrids, sorghum -sudangrass hybrids enhanced with the Brown Mid Rib (BMR) gene, forage sorghum, sudangrass, and forage millets. Recommended seeding rates for these species vary considerably by forage type and range from 25 to 60 lbs per acre. These forages should be harvested when they reach approximately 30 inches. It is important to note that these crops need high temperatures to yield well and may not be the best choice if growers are experiencing cool to average temperatures. Studies conducted at the University of Wisconsin have reported summer annual yields between 2 and 6 tons/acre and RFV between 90 and 100 (Undersander and Lane, 2001).

There has been a lot of interest in growing sorghum-sudangrass enhanced with the BMR gene. The BMR gene has a characteristic of reduced lignin content, and hence tends to be highly digestible. The seed should be drilled ¼ to ½ inch deep at a rate of 50 lb/acre and fertilized the same as corn. Harvesting should take place after the grass is 30 inches tall or just before heading (Undersander and Lane, 2001). If planting is done by the first half of June, a second harvest can probably be made in September. Reports from Cornell University show that the forage quality of BMR sorghum-sudangrass can have a digestible neutral detergent fiber concentration (dNDF) of almost 70%and crude protein (CP) of up to 18% (Ketterings et al., 2002).

References and Citations


Posted: August 27th, 2012 by outcropn

Vermont dairy farmers will once again have an opportunity to purchase federal insurance which protects the gross margin between low milk and high feed prices through the USDA’s Livestock Gross Margin for dairy cattle program.  UVM Extension’s agricultural economist, Bob Parsons, said that Vermont dairy farmers took full advantage of the program during prior sales periods, insuring over 6.8 million pounds of milk.  With feed prices at record highs, this insurance can help pay the bills and cover living expenses, says Parsons.

Due to higher than expected nationwide interest last fall, all the remaining funds for the program were committed.  However, an additional $2.5 million has been made available nationally by the USDA.

The sales period will open this Friday, August 31, and it is expected that the demand will quickly exceed the funds.  Farmers interested in purchasing Livestock Gross Margin insurance for dairy cattle should contact a crop insurance agent immediately.   For more information, call UVM Extension at 802-349-2966.

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