Posts Tagged ‘pasture’

The Word is Out: Roundup Ready® Alfalfa Gains Approval for Spring Planting

Friday, March 11th, 2011

In a press release through Reuters on Jan. 27, 2011, the word came down that the United States Department of Agriculture (USDA) has approved GMO alfalfa without restrictions and that the alfalfa can be planted as early as this spring. Surprising few in the agricultural community, Secretary Vilsack stated that there are no doubts about GMO crop safety and that APHIS has determined that Roundup Ready alfalfa is as safe as traditionally bred alfalfa.

Many in the industry had expected that a compromise was in the works that would place limitations and restrictions on planting Roundup Ready alfalfa and that the process of defining those limits and restrictions would delay approval past spring planting time. This worry proved unnecessary as no restrictions were announced on Thursday. Many conventional and organic producers are very worried that pollen from Roundup Ready alfalfa carried by the bee pollinators will end up pollinating their conventional or organic alfalfa seed sources. Actual hay and feed producers have less to be concerned about since if they are managing their alfalfa correctly, the crop should never reach the seed set stage of growth. Also since alfalfa has its own regulatory means (autotoxicity) of preventing self-generated seed from germinating and establishing in an established stand of alfalfa, there should be minimal chance of contamination of a stand during its lifetime as a hay, greenchop, haylage, or grazing field.

Secretary Vilsack said that the USDA would promote research into how genetics could be used as a means of preventing contamination and research designed to improve detection of any contamination that might occur. The Secretary will have the USDA set up two advisory committees to help ensure the availability of high-quality seed and to set up programs to try to protect the purity of the alfalfa germplasm base.

Time for Frost Crack Seeding of Small-Seeded Legumes

Friday, March 11th, 2011

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

Many growers like to overseed with legumes into their pasture and hay fields by using a method called frost-crack seeding. An article with full details was published in the Mid-Atlantic Regional Agronomist Quarterly Newsletter in September 2006 in Issue 1, Number 3 for those who would like a more detailed description of the seeding method. This publication is available on-line at either of the following locations:

http://www.grains.cses.vt.edu/ – look for Mid-Atlantic Regional Agronomy Newsletter
or
www.mdcrops.umd.edu -click on Newsletter

For a quick review, let’s look at the seven steps to take when considering a frost-crack seeding of forage legumes.

Step 1. Evaluate your soil fertility and soil pH status either by reviewing past soil test reports or in the fall prior to the seeding taking a soil sample of the chosen field. Make corrections in pH by liming the fall or spring before overseeding as well as making corrections in the phosphorus (P) and potassium (K) status. You should avoid nitrogen (N) fertilizer additions in the fall prior to frost seeding the field as fall applied N will be picked up and stored by the grasses (and weeds) present and will stimulate serious competition for the legume seedlings the next spring.

If you’ve waited until the spring of the frost crack seeding, as many of us do, then use your old soil tests to determine the field’s fertility status and take this into account when you are making your species selection in Step 3 below.

Step 2. Provide seedlings with more sunlight and less competition as well as make it easier to get soil to seed contact. By this I mean that, when possible, the fall before a frost-crack seeding, you should graze or mow the field very close to stress the grass present to make it less competitive the following spring. This activity can be repeated just before overseeding to maximize soil exposure to the seed and to freezing and thawing temperatures.

Step 3. Select the correct species for your situation. In the Mid-Atlantic region, we have three primary clover species from which to select. For fields that are generally wetter or lower in soil pH, alsike clover may be the best choice. All-around, white or ladino clover seems to respond best to this method of seeding, especially under good soil fertility levels. Red clover is another species that responds well to frost-crack seeding but it is a taller growing species but like alsike clover it is a short-lived perennial.

If you decide to base your selection on the grazing animal species you have, then for horses I would choose white clover. You will need to keep the seedling rate lower since we recommend not having more than about 20 percent white clover in a horse pasture even though this limits the effectiveness of the legume in providing N for the companion grass crop. For beef, all three species are suitable but for small ruminants where close grazing occurs, white clover is probably the best choice.

For hay production fields where some legume contributed N is desired to boost grass yields and lower N fertilizer costs, the choice is more problematic. The tall growing species, red clover and alsike clover, have certain limitations. Red clover is more difficult to dry and because of the fine hairs that are on stems, petioles, and leaves it can make for dusty hay. Alsike clover is not suitable for the horse hay market since some horses develop alsike clover poisoning which shows up as photosensitivity causing the animal to sunburn easily. I’ve seen a vigorous tall growing ladino-type of white clover used in hay but its contribution to yield is limited to leaves and petioles since the stem stays on the soil surface. Ladino-grass hay for second and third cuttings can be very good although producers often are disappointed in the amount of legume in first cutting hay.

Finally on species selection, many of the species that contain quantities of condensed tannins that are thought to be useful in small ruminant parasite control are very difficult to establish using the frost-crack seeding method. The legumes in this category such as Birdsfoot trefoil and Sericea lespedeza are suited for more conventional seeding methods.

Step 4. Inoculate the seed before planting. Although we consider the probability very high that white, red, and alsike cover inoculating bacteria are present in all pasture and hay fields, a good habit to get in is to either buy preinoculated seed or inoculant for the seed. If preinoculated seed is past its sell by date, you should add more inoculate before seeding. Also when you buy the inoculant, check the label to be sure that you are within the expiration date on the package. Inoculant consists of live bacteria so protect its viability by keeping it cool and out of sunlight.

Step 5. Calibrate your seeding method and equipment to be sure that you are putting on the correct amount of seed. Making a pass over a parking area or tarp that’s been placed on the ground is a good way to check both the width of the application pass and the density of seeds per square foot. Careful attention to this detail will pay extra dividends later in the season. This is especially true for broadcast spreaders or cyclone spreaders that fling the seed outward. Although clover seed is light it is fairly dense and may not travel as far as you expect.

Step 6. Frost seed at the correct time. Do not frost seed so early that the seed sits on frozen soil where heavy rainfall can move it off site. Also, do not frost seed on snow covered soil since rapid snow melt can again move the seed off-site. Instead seed in very early spring once the soil has at least begun to thaw, daytime temperatures are enough above freezing that the surface of the soil will thaw, and nighttime temperature are below freezing. You will need a number of weeks of this type of weather (at least off and on) to work the seed into the soil. You can also help in this process by allowing grazing animals access to the pasture or by running over hay fields with the tractor and mower. In addition to pressing the seed into the soil, you will also help reduce competition against the legume seedlings as they emerge and try to establish themselves.

Step 7—The Final Step. Essentially by returning to Step 2, your goal again is to control spring vegetation growth to encourage enough sunlight, nutrients, and water reaching the legume seedlings that they can effectively compete and establish themselves. Grazing can again help at this step but you will need to manage the grazing intensity closely as well as frequently so that you prevent the animals from grazing the tender young leaves of the new legume plants. As soon as you notice animals feeding on the new legumes or the legume reaches a height that will tempt the animals, remove them and change over to mowing. Once the plants have 6 to 8 trifoliate leaves or reach a height of 3 to 4 inches, the legume should be able to compete with the grass and weeds present in the pasture or hay field. Do not apply N-containing fertilizers since this will stimulate grass growth and suppress the nitrogen fixing ability of the legumes. Use grazing or hay harvest management techniques and fertilizer (lime, P, and K) management to favor the legume species you frost seeded. A rotational grazing system or hay cut system designed for the legume seeded can help ensure a longer lasting stand.

Consider Temporary Annual Forage Crops for Fields to be Planted Later this Year

Friday, June 4th, 2010

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

If you were one of those producers whose pasture or hay field replanting was prevented by this past spring’s cold rainy weather, now is the time to consider a method of preparing the field for late-summer/early-fall (LS/EF) reseeding. The beginning of June’s hot weather (warm soil conditions) is ideal for seeding warm-season annual, weed-suppressing grasses such as hybrid pearl millet, sudangrass, the sorghum-sudangrass hybrids, or even teff. These grasses, if seeded when soil temperatures are >75° F and adequate soil moisture is present, can germinate and establish very rapidly. They have the ability to suppress many weed species and can add organic matter to the soil via the root mass left at the end of the season or the root mass plus final top growth of the season.

Another advantage of the warm-season annual grasses comes from the need for land preparation prior to the permanent LS/EF seeding. This soil preparation provides the producer with the opportunity to check the pasture or hay field’s soil fertility status and to make early adjustments that can be rechecked prior to planting the more expensive perennial grass seed. As an agronomist, I typically recommend checking six months to a year ahead of reseeding a field so that pH adjustment (liming) and nutrient amendments (phosphorus, potassium, or manures) can be applied and will have time to correct any problems in the field. Although the timing here may be tight, it still will allow a producer to recheck the field before establishing the permanent cover.

Another obvious benefit is the increased tonnage the summer annuals offer forage producers. However, care must be taken in selecting not only the annual grass species but the animal species that the forage will feed. Summer annual grasses can have a number of limitations/problems that can be successfully managed by the knowledgeable producer.

Common to all the species (even the cool-season grasses) is the potential for nitrate accumulation and nitrate toxicity during drought or cloudy weather when nitrates are not metabolized rapidly enough by the plant into proteins and amino acids. Nitrates taken up from the soil then accumulate, especially in the lower stems, and can reach toxic levels and are not reduced during hay harvest. Cyanide toxicity issues exist for sudangrass and the sorghum-sudangrass hybrids but this can be managed with grazing or cutting height. Sorghum species and species such as foxtail millet (Setaria spp.) can be harmful to horses (cystitis problems to name one concern). Hybrid pearl millet and pearl millet do not cause these problems and are generally considered safe for horses. Most of the species also have thick stems and large leaves that make hay making a bit more challenging. With careful management, the benefits from weed suppression, forage production, soil tilth, and early soil fertility adjustment out-weigh other concerns.

Managing Compaction on Pastures when Soil Moisture Content is High

Thursday, May 6th, 2010

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

During the rather warm weather of this past weekend I spent a couple of relatively uncomfortable nights when our new air conditioner wouldn’t start. Although this can hardly be called earth shattering news, it did bring to mind how we all seem to have forgotten the days when AC was not available and wasn’t built into our tractors as standard equipment. Following the uncomfortable weekend, I was asked if it is important to consider how wet some pastures or areas of pastures are when choosing the tractor to use when dragging a chain drag across the pasture to break up manure piles. Although we might be tempted to use whatever sized tractor we have that has AC and all the comforts of modern equipment, it is important to keep in mind that we should use only as large and heavy a piece of equipment as is necessary to complete the job. In the case of dragging pastures to spread manure piles to prevent the piles from killing the grass/legume beneath them, a small tractor or ATV capable of pulling the chain drag is all that is needed.

Although grazing animals can contribute to compaction issues, I think it is good management to minimize all other sources of compaction. Mowing recently grazed pastures or dragging them to redistribute the manure are excellent practices in their own right. Mowing leftover spring grass removes seed heads and stimulates the grass to produce new vegetative tillers that are high in nutritive value. Spreading manure helps it to dry out and get into contact with more soil surface area to encourage rapid decomposition. Dragging manure spreads the nutrients over more land area and removes manure piles that can suffocate or shade out the underlying grass creating space for weed encroachment. When piles are not broken up and distributed around the pasture, animals selectively graze away from the grass in and around the pile causing reduced utilization of the pasture.

Choosing to use the biggest and perhaps newest heavy duty equipment can make the job of mowing or dragging pastures more tolerable but in the process of doing a good management practice you end up cancelling all the good you will be doing by causing more compaction problems, especially in the wetter areas of a pasture. Compaction, and especially deep compaction issues, are very difficult to resolve without a total pasture renovation in which the pasture is deep ripped, tilled, and replanted. Compaction issues tend to be cumulative until poor productivity or weed competition becomes severe enough to demand a solution — total pasture renovation. So, take out the sun screen or pull on a large hat, wheel out the four wheeler or one of the older, smaller tractors and avoid more compaction!

Hay and Pasture and Potash

Thursday, May 6th, 2010

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

Although it’s a little earlier than normal, I think it’s time to start thinking of applying spring potash (K) and phosphorus (P) fertilizer to your pasture and hay fields. For the hay fields, you will want to wait until after the first harvest, but I’ve seen a number of fields at heading (grasses) or late bud (alfalfa) which is a good time to harvest a good to excellent quality hay. For those more interested in tonnage, you’ll be holding off harvest for a few more weeks but you can still plan ahead for when your fields will be ready to fertilize with P and K and another shot of nitrogen (N). The warm weather of the past week and the period of very warm weather earlier this spring has orchardgrass and many other cool-season grasses heading out already. Early May is also, on average, a time when we have the greatest chance of a period of warm sunny weather long enough to dry hay.

Potassium or potash is a very critical element that helps plants tolerate the stresses of heat, drought, insects, and diseases that attack cool-season grasses in the summer. Although the price of K is high at the present time, the corresponding benefits of K fertilization will help you afford the cost of fertilizing with K. Many growers have chosen to either lower their K fertilization rates or eliminate them completely during the past couple of years when the price of fertilizer has been very high. If you have a current soil test, check the recommendations for how much K might be needed. If your soil test is not current you should get one as soon as possible to determine how much K you should apply or to see if the soil test levels are falling too rapidly.

In general if both P and K are needed by your hay or pasture field, add the P and half the K after the first hay harvest or in late-May or early June and then add the second half of the K recommendation in late August or early September. This timing will allow the plant to prepare for the stresses of summer and then for the stresses of winter.

Spring Wake-Up of Pasture and Hay Fields

Friday, March 27th, 2009

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

It’s hoped that your pastures and hay fields have made it successfully through another winter. Now it’s time to get pastures actively growing for the needed grazing to extend your hay supplies or reduce the need to buy more hay and it’s time for hay fields to green up and be ready for the first good hay making weather later this spring. Many of our hay and pasture fields have had a relatively hard winter with little snow cover and some very cold temperatures.

If the stands have thinned a little or if you just want to speed up growth this spring to be able to graze earlier or boost spring hay yields, now is the time to add a bit of nitrogen (N) to give the grasses a boost. If the field has a good amount of legume present, you should restrict the amount of N applied at any one time to no more than about 30 lbs N/acre. However if few legumes are present in the field, then addition of 50 to 75 lbs N/acre will stimulate the grass to grow and fill in bare spots or at least tiller out fully to help shade out weeds that might try to fill in any void spots.

Unless your soil test shows low to very low levels of phosphorus (P) and potassium (K), you should wait until after the first hay harvest or early to mid-June to apply the P and K that might be required according to your soil test recommendations or your nutrient management plan. Generally, the freezing and thawing and other reactions that occur over the winter months will release enough available K and P to support spring forage growth.

Still Time for Frost-Crack Seeding of Pastures

Friday, March 27th, 2009

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

Frost crack seeding is an inexpensive means of establishing or reestablishing legumes in pasture or hay fields. This method is ideally suited to fields too small or irregularly shaped in which to use large equipment. It is most appropriate for use with small-seeded legumes such as white, ladino, or red clover, although it has been used with grasses and, on rare occasion, with larger-seeded legumes such as hairy vetch and alfalfa (low probability of success). If done at the correct time and managed properly to improve the success rate, frost crack seeding can be a very inexpensive tool available to all forage producers regardless of size and level of technology.

The principle involved in frost crack seeding is to seed during late winter or very early spring when freezing and thawing of the soil is producing frost action with ice crystals coming out of the ground and opening cracks in the soil. If the legume or grass is broadcast over the field surface the freezing, thawing, and refreezing will incorporate the seed to some degree into the soil to enhance germination. Also, the seed is present during a cool, moist time that favors legume germination before summer annual weeds germinate. Usually, this occurs between late January and late February although this year we’re still having favorable conditions even this late in March.

In frost seedings, either the frost action or livestock activity is used to control competing vegetation, prepare a seedbed, cover the seeds, and provide seed to soil contact for germination. If there is not sufficient frost action after applying seed and animals are available, allow animals to walk the pastures to tread seed into the soil surface. This should be done only when the soil is firm enough so that the cattle or horses will not punch through the sod and push the seed too deep into the soil.

Grass seedings may not be successful with the frost crack method. It is likely that the smaller seeded grasses (timothy, Kentucky bluegrass, and orchardgrass) will be the most easily established with this method. The success rate can be increased if the field is mowed or grazed very short in the fall or winter before seeding. Results of the seeding often are not evident until at least midsummer. The legume or grass plants are very small early and will need as much sunlight and as little competition as possible to allow them to become established. Fields grazed down to 3 or 4-inch stubble will have a higher probability of success. Hay fields where existing vegetation can not be controlled to reduce its competition with the new seedlings will see far fewer surviving seedlings than in pasture situations.

Of the legumes that have been successfully over-seeded into cool-season grasses, red clover is the most productive, ladino clover is the easiest and least expensive to establish, and annual lespedeza is the most versatile. Red clover generally will not survive more than two years due to the buildup of disease organisms in the soil. White or ladino clover are shallow rooted with surface stolons but can survive for many years if adequate soil moisture is available and harvest management is favorable. Under the best conditions, frost seedings succeed in only three or four years out of five but remain a less expensive option for producers who must rent or otherwise obtain no-till seeders. The lack of good soil-to-seed contact increases the risk of failure and even in successful years it often means that although the percentage of legume is increased the legume stand is not uniform. This often is acceptable to grazers but not to hay producers.