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Planting a New Pasture of Hayfield? Part 6: Managing Pasture and Hay Fields for Long-term Health

Posted on by truehart

Part 6: How Do I Manage My Stand So It Stays Healthy and Productive?

In Part IV, I discussed the advantages of planting into moist soil during the ideal planting window for the selected forage species. I then discussed the planting options such as conventional seedbed preparation and no-till seeding. Along with these options, I discussed the need for calibration of the planter or drill to ensure the use of the proper number of pure live seed (PLS) per acre. Let us assume that the new planting has emerged from the soil so it is time to think about how to properly manage the new seeding to ensure a successful establishment and long-term productivity.

Usually even before the seed germinates, grazers want to know when they can return animal to the pasture to graze it. Hay producers have an easier time deciding when to begin using a new field especially for fall planted fields since cool-season grasses will signal their successful establishment by flowering in late spring or early summer the year following seeding.

For new pastures, the key to long-term health of the pasture is to wait about 12 to 18 months before grazing a new field. This means that the new pasture will need to be hayed at least once and possibly several times in the year following fall seeding. From a practical viewpoint, few grazers will wait 12+ months since it means not grazing the field until the second spring following fall seeding. At a minimum, a new fall-seeded pasture should be hayed in late spring or early summer the year following seeding and then allowed to regrow to a height of 8 to 12 inches before grazing is begun. It is possible to plant in the fall and begin grazing first thing the following spring but you will be sacrificing stand health and longevity with this practice.

Nutrient management plans call for a new soil test once every three years but a yearly sample will help the grazer manage the pasture better. This is very important if nitrogen (N) fertilizer inputs are used to stimulate the productivity of a pasture. Even without N fertilizer applications, the natural deposition of urine and feces in a pasture creates small areas where the process of nitrification produces acidity that can significantly lower soil pH in the small area. Higher stocking rates and intensive pasture rotations will result in more uniform spreading of the urine and feces (especially for ruminant animals); and therefore, a greater proportion of the pasture will be impacted by lower pH (more acid soil conditions). Since it can take a year for lime to move an inch down through the soil, yearly soil testing will allow the grazer to begin neutralizing soil acidity as it is produced by the soil N-cycle.

Another aspect of soil fertility to consider is the use of fall applied N to improve the rooting of pasture plants as well as help stimulate growth the following spring for early grazing. Although the practice has long been used in the turfgrass industry, those of us in forage management are just realizing the potential benefits to pastures of fall N applications. Small amounts of fall N (about 30 lbs N/acre) should be applied in mid-October and mid-November since at these times topgrowth has ceased but the deep soil layers are still relatively warm. The N stimulates further root growth creating pasture plants with deeper and larger root systems as they enter the winter period. Some of the N is stored in the plant and available to stimulate topgrowth the following spring as the hours of daylight increase and air temperatures warm. This type of fertilization makes for a stronger plant going into the summer months (greater rooting depth and therefore greater available soil water to draw on) and can improve the competitiveness of the pasture grasses against weeds.

Probably the number one key to maintaining the health and competitiveness of a pasture is to use rotational grazing where plants are allowed to fully recover from the prior grazing period (grow to a height of 8 to 12 inches or more) and the grazing interval is kept short enough that the same plants are not grazed over and over again during a rotation cycle. Generally, this means rotating livestock out of a paddock or grazing cell within three days of moving the animals into the paddock. This time can be stretched to as much as a week but the more rapidly the animals are moved among paddocks in the rotational grazing scheme the healthier the pasture. Another aspect to using rotational grazing is to not put animals on pasture when soil conditions are too wet when the presence of animals can lead to compaction issues. Not grazing when plants are under drought stress is also a key consideration. Use the extra forage produced during the spring and fall to make hay that can support animals on a heavy use pad during periods of wet weather, drought, or other conditions leading to poor pasture growth.

Another method used to maintain healthy and vigorous pastures is to periodically overseed pastures in the fall with grasses and/or legumes. Some producers do this every year while others do it every couple of years. In most cases, the new seedlings must compete against the established plants in the pasture so that there is often limited ‘take’ from the germinating seed. However in the weaker areas of the pasture stand, there will be more light, water, nutrients, and space for the seedlings so establishment will be better in these areas. The weak areas would be where weeds could become established but by overseeding the pastures weed encroachment is limited or prevented.

The species to use for overseeding should be those species that can grow rapidly especially in the cool conditions of late summer and early fall. This would include such species as the ryegrasses, festulolium, ladino white clover, and red clover. Although just broadcasting the seed over the surface and then using a chain harrow or other implement to slightly cover the seed has been used, the best seeding method is to use a no-till drill and drill the seed into the soil. Seeding rates typically used are about one-quarter that of a normal new pasture seeding rate since most of the seed will be planted where established plant competition will not allow the new seedlings to establish successfully.

Finally, the producer can manage the balance of legumes and grasses in the pasture by his/her fertilization practices. Potassium and phosphorus applications along with 1 to 2 lbs of boron per acre per year and maintaining a near neutral soil pH (6.5-7.0) will encourage legume growth. If the percentage of legume is too high and the risk of bloat is too great, N application to encourage grass growth can be used to lower the percentage of legume in a pasture. Grasses with their fibrous root system are much more competitive for applied N than are the tap-rooted legumes. The available N will stimulate the grass and help it shade the legumes as well as change the proportion of legume to grass biomass.

This article was submitted by Dr. Richard Taylor, Extension Agronomist, University of Delaware.  Dr. Taylor can be reached at rtaylor@udel.edu

Is It Time to Plant a New Pasture or Hay Field? Part 5: Planting the Crop

Posted on by truehart

Part 5:  When Do I Plant and How Much Seed Do I Use?

In the earlier posts in this series, I discussed some of the decisions and planning that need to be taken ahead of planting hay and pasture fields.  For this article, we have entered the ideal planting time for forage grasses and legumes.  However although we are in the ideal window for planting, there will be areas that have received enough rainfall to recharge the topsoil with moisture as well as areas that have not received enough rainfall for a successful seeding.  For those areas that remain dry until mid- to late-October, the best decision is likely to postpone planting until next year.

Some species have specific requirements that limit how late in the fall you can plant.  For example, reed canarygrass requires at least six weeks between planting and the average date of the first frost; otherwise, the crop could be winterkilled or severely weakened over the winter leaving the crop unable to compete with the usual spring flush of weeds.  Other species, such as Kentucky bluegrass, just take a very long time (21 to 28 days) to germinate and should not be planted late in the fall.  Before deciding to plant a species or mixture, be sure to study the species in question to avoid missing the ideal planting window.

In areas that have received enough rainfall to replace soil moisture reserves, planting can begin.  Early planting can lead to well established forage seedlings that are able to survive winter temperature extremes and get off to an early vigorous start next spring.  Early planted stands are better at competing against weeds next spring and often produce higher yields as well.  Work by Dr. Marvin Hall at the Pennsylvania State University showed significant yield decreases for all forage species tested as the date of fall planting was delayed with higher losses occurring the further north the site was located.

If planting into a prepared or tilled seedbed, be sure that all weeds have been killed during soil preparation and that a good smooth (clod-free), firm (your shoe should not sink deeper than the sole level) seedbed is prepared for planting.  Seed is then broadcast on the seedbed and firmed or pressed into the soil with any number of devices.  Seed of small seeded forages should not be buried more than 1/8 to ¼ inch deep.  Covering the seed is ideal since seed in contact with moist soil readily absorbs water but is not quickly dried again by the heat from the sun.  Seed can also be planted using a Brillion seeder followed by a cultipacker or roller or seed can be placed in the soil using a drill with packing wheels that firm soil over the seed.

Since drills (no-till and conventional drills) place the seed in rows from 4 to 8 inches apart, depending on the drill, I generally recommend that you drill at half the recommended seeding rate and run the drill twice over the field at about a 45 degree angle.  This will help new seedlings to cover the soil surface more quickly and reduce the chances for weed seed to germinate and compete with the new forage crop.

Another method of seeding is to use a no-till drill following an herbicide burn-down program.  This is especially useful when perennial weeds with underground rhizome systems are present.  Examples of these weeds are hemp dogbane, Canada thistle, and horsenettle.  Often several herbicide applications will be needed to get these weeds under control so plan a weed control program well ahead of seeding.  One of the best times to apply a translocated herbicide is in fall when weeds are sending carbohydrates (sugars) down to underground storage organs (rhizomes).  If a systemic herbicide that can move inside the plant is used, it will be taken with the sugars down to the rhizomes and help kill the meristem buds that are next year’s growing sites for the weed.  Read the herbicide label for the exact interval between treatment and seeding.  Generally for Roundup® or glyphosate you should wait several weeks after herbicide application before planting.  Since the herbicides used for control of these perennial broadleaf weeds will kill legumes that often are included as a component of pasture mixtures, it is best to work on controlling these weeds a year or two before spending the money to establish a new seeding or to renovate an existing stand.

In all cases I’ve talked about, be certain to calibrate your seeding equipment and make sure the drills and other equipment are clean and functional before entering the field.  These days forage seed is quite expensive so make the most of the money you spend by accurately calibrating your equipment.  This involves the following procedure:  weigh out some seed to add to the planting equipment, determine the width of area covered with seed by the equipment (in feet), run it for a certain number of feet (the length—say 50 or 100 feet); multiplying the two numbers together to get the number of square feet covered by the seed; divide that number by 43,560 (number of square feet in one acre); and finally weigh the amount of seed remaining in the equipment.  Subtract the final weight from initial weight and divide that number by the number of acres you covered (usually this will be a number such as 0.15 or even 0.015 or other very small number).  If your seed weights were in pounds of seed then the number you calculate at the end will be in pounds per acre or if you had access to an egg scale or something that measures in grams then divide the number of grams of seed used by 454 (grams per pound) to obtain pounds of seed and then divide that number by the number of acres planted in the calibration test.  If all else fails, email me or give me a call and I’ll help you do the calculations.

In summary, I’ll list some of the key points to keep in mind.

  • Make adjustments to soil fertility well in advance of seeding or renovating.
  • Have all perennial weeds under control before establishing a new seeding or conducting a major renovation in a field.
  • Monitor soil moisture levels to be sure an adequate reserve of soil water is available to establish the crop.
  • Understand the requirements for the forage specie or species chosen especially as it relates to fall planting date.
  • Start with a weed-free seedbed whether for conventional tillage or no-till.
  • Unless the site is known to be very low in available soil nitrogen (N), allow the new seedlings to develop 2 to 3 leaves before applying N in the fall.
  • Don’t delay planting; try to hit the optimum planting window.
  • Ideally, cover the seed with just a little soil but at the very least press the seed into the soil to ensure good soil to seed contact.
  • Most seeding rates really refer to the numbers of pure live seed (viable potential seedlings) that should be planted per acre so do the proper calculations to plant the correct amount especially when using coated seed.
  • If using preinoculated, lime-coated legume seed as a component of the pasture/hay mix, you should check to be certain the seed has been stored away from heat and high humidity and is not more than a year old, otherwise fresh legume inoculant should be applied to the seed just prior to planting.
  • Many small seeded species now come with a range of coatings (lime, moisture control compounds, etc.) that can halve the weight of pure live seed in the container so you should be sure to account for this when calculating the correct seeding rate.

In the last installment of this series, I’ll discuss how to manage new pasture and hay fields for long-term healthy stands.

This article was submitted by Dr. Richard Taylor, Extension Agronomist, University of Delaware.  Dr. Taylor can be reached at rtaylor@udel.edu

Is It Time to Think about Renovating or Planting a New Pasture or Hay Field? Part 4: Planting Method

Posted on by truehart

Part 4: How Should I Plant My Hay Field or Pasture?

What’s the best means of seeding fields, no-till or conventional tillage (a prepared, weed-free, firm seedbed)? As with any choice, there are advantages and disadvantages to each method. Both seeding methods allow for weed control activities before seeding but no-till is limited only to herbicide applications. Whenever deciding on an herbicide to use, read the label carefully to be sure there are no rotation restrictions of what can be seeded following the herbicide application or how many days or months must separate the application and seeding activities. Also use the label to determine if a single application will be all that is needed or whether you will need follow-up applications and if you will at what stage of growth must the new seedlings reach before the next application is applied. This latter concern is especially important for perennial and hard to kill weeds such as hemp dogbane, Canada thistle, horsenettle, and others.

No-till drills must be calibrated properly to deliver the correct amount of seed per acre as well as be set to place the seed at the correct seeding depth with adequate soil to seed contact for fast germination and emergence. Never assume that the last person to use the drill set it up properly for your seeding. When you spend a hundred or more dollars per acre just for seed, you need to be sure the seed is being planted as best as possible to ensure a successful establishment. No-till drills also place the seed in rows usually from 7 to 10 inches apart so it often is useful to cover the seeded area in two directions making a cross hatch pattern over the field to help the plants fill in the space quicker. Brillion seeders that broadcast seed over a prepared seedbed and then press the seed into the soil have the advantage of achieving canopy closure much sooner than no-till seeding.

Canopy closure is when the new plants get large enough that they are able to shade the underlying soil and therefore reduce the ability of weeds from germinating and establishing in the field. Fields seeded with no-till drills can be many years (if ever) filling in so that a full canopy exists during normal grazing activity. This is one disadvantage to the no-till drill although it is offset by the soil conservation advantage of no-till when a field has enough slope to allow significant water erosion or enough exposure to allow wind erosion problems if the weather turns dry again.

Which method is best? Since each has both advantages and disadvantages, it will depend on your situation. No-till helps conserve the soil in situations where soil can be loss; it reduces moisture loss since the soil is not disturbed; it doesn’t encourage new weed growth since buried weed seeds are brought to the surface; it does not introduce oxygen into the soil causing the soil organic matter to be reduced via oxidation; and when done correctly it ensures rapid germination and emergence since seeds are placed in the soil and soil is firmed around the seeds. From the negative side, no-till does not allow nutrients and lime to be worked into the soil profile; no-till does not help break up compaction issues from previous grazing or haying equipment use; and no-till seeding is often in rows that can be seen for years in some cases.

Conventional tillage does allow nutrients and lime to be incorporated in the soil; it allows tillage during the summer to help with weed control issues; it allows for the summer establishment of annual smother crops for weed control and to introduce organic matter into the soil; it allows you to rip fields to help alleviate compaction issues; and it allows seed to be broadcast to ensure rapid canopy closure. Some of the disadvantages include the loss of soil moisture during the tillage operation as well as the loss of soil organic matter during tillage. The above lists of advantages and disadvantages are not meant to be exhaustive but to point to some of the important factors you should consider when deciding on seeding method.

This article was submitted by Dr. Richard Taylor, Extension Agronomist, University of Delaware.  Dr. Taylor can be reached at rtaylor@udel.edu

Is It Time to Think about Renovating or Planting a New Pasture or Hay Field? Part 3: Planning to Planting

Posted on by truehart

In Parts I and 2, I covered testing the soil in the field in which you plan to establish a new pasture or plan to do a total renovation and species selection.  Depending on how close you are to planting and whether you will be working the soil or planting using a no-till drill, it’s probably time to recheck soil pH and fertility levels in the field to be planted or renovated.  The final soil test should be taken approximately 6 to 9 months after the earlier limestone application.  This should be enough time for previously applied lime to react with both the active acidity (hydrogen ions in soil solution) and the reserve acidity (hydrogen and aluminum ions on the clay and organic matter cation exchange sites) and the soil pH to be reaching an equilibrium state.  In this way if another smaller application of limestone is needed to move the soil pH slightly higher, the lime can be applied and worked in the soil, assuming some type of tillage for incorporation of the limestone. In no-till situations, the process of adjusting the soil pH takes much longer and should be started as much as two or three years in advance of seeding or renovation  since lime moves downward through the soil at about one inch per year.

Now that the soil fertility requirements have been completed, it’s on to the planning and planting process.  One of the biggest challenges these days, especially if you have a small number of acres in the field, is finding someone with equipment the right size to fit the field and a willingness to do the job in a timely fashion.  Of course even if you’re lucky enough to find the equipment and operator, cost is going to be a critical factor when making the decisions of what parts of the plan are actually doable.  Another factor that has become more of a challenge in recent years is the availability of forage seed of the selected species and variety.  Many forage seed production fields have been converted to row crop production and in some locations restrictions on burning seed production fields have allowed disease issues such as ‘choke’ to reduce forage seed yield potential.

In planning the whole procedure, your time will be a valuable asset.  With high prices, limited seed supplied, and challenges in finding equipment and help to fertilize, lime, control weeds, and plant seeds, the time you take to shop around should pay big benefits.  July and August are the time to do these chores since the fall planting season is right around the corner.

For planting date, forage agronomists often list from mid-August through September as being the time to plant as long as soil moisture is adequate.  Soil moisture for many hay producers and grazers in the state and region really will be at critically low levels for much of August.  This can extend late into September due to the drought and hot weather conditions we usually experience during July and August.  With all our pre-planning and planning activities, the final decision on when to plant and even whether to plant on time will be determined by the weather conditions during August and September.  You may be tempted to plant as soon as the field receives the first rainfall in the planting window but you should keep in mind that if the deeper layers of soil are deficient in moisture the new planting will likely fail if fall turns dry.  Use a shovel or your soil probe to test the soil for moisture at the 6 to 12 inch depth.  If the field hasn’t received enough rainfall to supply this soil depth with at least some water, a new planting will be very much at risk if rain events do not continue from planting until winter dormancy takes hold.  Only you know the amount of risk you are willing to take to establish the new seeding this season and none of us know what the future weather will be.

What if enough rain to supply water to the deeper soil layers doesn’t fall until very late in September?  Certain species, such as low alkaloid reed canary grass, require a specific amount of time between planting and first frost (six weeks minimum for reed canary grass) but almost all species will not only yield less the following year but take a lot more time to reach full establishment if planted late.  Again, the hay producer or grazer must evaluate the amount of risk they are willing to take on when deciding to plant after September.

You should maintain frequent contact with your fertilizer/lime dealer, seed dealer, equipment supplier, and others who will be helping you with the process of planting the new pasture or hay field.  If you will be using equipment provided through the county conservation districts, be sure to get your name on the list as early as possible since many folks may want to seed about the same time when moisture conditions become favorable.

This article was submitted by Dr. Richard Taylor, Extension Agronomist, University of Delaware.  Dr. Taylor can be reached at rtaylor@udel.edu

Is It Time to Think about Renovating or Planting a New Pasture or Hay Field? Part 1

Posted on by truehart

Part 1: The Pre-Planning Process…

Over the years since I first came to Delaware, I have received numerous requests concerning overseeding or renovating pasture and hay fields.  Unfortunately, these requests usually come about just before someone wants to actually plant.  In reality, producers should begin considering the process as much as a year ahead of the actual time that they want to plant a field.  Since our fall plantings of forage crops seem to perform better than spring plantings, it’s a good time to begin a discussion of the process.  Often, we find ourselves moving into mid- to late-fall without having taken the time to really consider all decisions that have to go into improving the odds that the planting will be successful.  Seed costs alone can equate to more than a hundred dollars per acre in investment expense; and, if we really take into account all the variable costs, a new pasture or hay field can easily represent an investment of hundreds of dollars per acre.

So in the pre-planning process, what’s first?  I know many get tired of hearing the phrase but testing the fertility of your soil far ahead of time is still the number one issue.  The proper sampling depth is 0 to 4 inches in fields where you will be using a no-till drill to seed the forage and on fields that you do not plan to use deep tillage and have not been applying significant quantities of commercial nitrogen (N) fertilizer.  In these instances, you will not be incorporating lime to neutralize acidity from the N fertilizer or incorporating large amounts of phosphorus [P or (P2O5)] or potassium [K or (K2O)] fertilizer.  Your expectation is that the soil test will indicate that the soil pH is in the 6.0 to 6.8 range and the P and K levels are in the medium to optimum range.  If your expectations do not prove true and the pH is low enough to require several tons per acre of limestone or the P and K levels are low to very low and the fertilizer and lime needs to be mixed into the soil thoroughly, you will need to change plans and consider some type of tillage to incorporate fertilizer and/or lime.

If you have used large quantities of commercial N fertilizer in the past, you really should take both a 0-2 inch depth sample for determining the soil acidity in the upper soil layer as well as a 0 to 4 inch depth sample for nutrient content (phosphorus, potassium, calcium, magnesium and other essential elements).  If you are unsure when limestone was last applied to the field, sampling both depths is a good approach since it will provide you with more information about the nutrient status of your field.

The reason for this distinction is that the ammonium or urea N forms that are applied as fertilizer are converted by soil bacteria into nitrate through a process called, nitrification,  In this process, the soil bacteria oxidize the reduced form of N and release hydrogen ions that cause the soil to acidify.  Since the N is all surface applied, the release of acidity near the soil surface can create a condition known as ‘acid roof’ where the top inch or two of soil is much more acidic than the deeper layers of soil.  A second reason involves the very slow movement of limestone down through the soil.  Studies on pastures in Connecticut many decades ago showed that lime moves downward at a rate of about 1 inch per year.   Therefore, it takes a very long time to have an impact on the entire rooting zone of the forage grasses and legumes.

In fields where tillage is planned prior to establishing a forage crop, the traditional plow layer sample (0 to 8 inches) for both soil pH (acidity) and essential nutrient status is the appropriate choice.  If the soil sample indicates that the soil must be limed, apply the recommended amount of limestone and work it into the soil as soon as possible to allow time for the limestone to neutralize soil acidity before planting time.  If the weather after lime application and incorporation remains dry, the limestone will not completely dissolve and neutralize the soil acidity.  I recommend that producers take a second soil test before planting in late summer or early fall to determine if any additional lime is needed.  Additional agricultural lime and the recommended P2O5 and K2O fertilizer as well as any other needed nutrients can be applied and worked into the soil shortly before planting the field.

Everyone asks the question of whether to apply N at the time you plant a new field or seed a field you are renovating.  My preference is that you should wait until the new grass is several inches tall and has enough biomass and roots to compete for applied N and store any extra N for future growth.  Very small forage seedlings use and need very little N, no more than a couple of pounds N per acre, until they reach 2 to 4 inches in height.  Often the residual N from organic matter mineralization during the summer, will supply the small amount of N the seedlings require.  Once the forage plants have enough leaf area to capture the sun’s energy and convert it into more plant tissue or into sugars for storage, the demand for N will increase significantly.  When forage seedlings are very small, weeds or current vegetation in renovated fields are likely to be better  able to compete with new forage seedlings for N, light, water, and other nutrients.  Although annual weeds and/or current vegetation will be present when N fertilizer is finally applied to the new seedlings, the perennial forage seedlings will be in a better competitive position to compete for the components needed for growth and establishment.  Summer annual weeds that germinated with the forage crop will be killed at the first fall/winter frost and provide the forage plants with more space, sun, water, and nutrients.

In the next installment, I’ll cover the question we most commonly receive, “What should I plant?”

This article was submitted by Dr. Richard W. Taylor, Extension Agronomist, University of Delaware.  Dr. Taylor can be reached at rtaylor@udel.edu