http://www.connix.com/~mlfarm/rural/past.html#credit -- Lawrence F. London, Jr. mailto:london@sunSITE.unc.edu http://sunSITE.unc.edu/InterGardenTitle: Pasture FAQ
© 1997 Ronald Florence
On many high-productivity farms today, the answer might be `nostalgia' or `to clean up odd corners that the tractors can't reach.' Some large, mechanized farms get along with no pasture at all. Dairy cows are fed silage, hay, and grain; market lambs and beef cattle are fattened in feedlots; horses get by on stall feeding. In the interest of efficiency and maximum gains, pasture is sometimes limited to dry cows or rams after breeding.
The economics of high-productivity mechanized farms don't necessarily apply to smaller farms, and especially hobby operations, where pasture can provide excellent low-cost feed, savings in hay and manure handling, a healthier environment than the barnyard or feedlot, extra-clean wool or grass-fed lamb or beef for specialty markets, long-term benefits to the land, and the pleasures of watching foals or lambs gambol on a grass field.
Pasture needs depend on local rainfall, forage quality, the availability of alternate pastures for rotation, the level of fertilizer and other nutrients applied to the pastures, the time and equipment available for pasture maintenance such as clipping or taking a cutting of hay, the length of the grazing season, and whether the pastures are primary or supplementary feed.
The common rule of thumb is that one acre of permanent pasture can support one animal unit (one cow or horse, six sheep or goats) through the grazing season. Pasture productivity can vary widely from that guideline. Lush improved pastures can provide grazing for 10-12 ewes with their lambs per acre. Stocking rates for aggressive rotation, with substantial rests for the pastures after each grazing cycle, can reach 6 cows or 36 sheep per acre on improved pastures. At the other end of the scale, a cow or horse would have trouble supporting itself on five or even ten acres of dry Western native grassland, and one sheep per acre is the rule on some Australian sheep stations.
Too much pasture can be as big a problem as too little, unless you can take a cutting of hay when the forage gets ahead of the animals, or use a mower to clip weeds and over-ripe grass to provide fresh grazing. See the Haying FAQ for information on haying practices and equipment.
In most cases, you can graze different animals together, and their different grazing and browsing patterns will increase the productivity of your pastures. Horses and cattle mostly eat grasses, and only occasionally eat forbs or browse brush and trees. Goats eat mostly browse, with a much smaller intake of grass and forbs. Sheep eat younger grasses, forbs, and browse. By taking advantage of the different patterns, you can not only increase the productivity of your pastures, but keep weeds and brushy growth under control with minimal mowing and herbicides.
Often, additional animals of a different species can be added to your pastures without reducing the existing population. As a rule of thumb, adding one ewe for each grazing cow will not require additional pasture. Other combinations may require experimentation. Another useful grazing scheme is to rotate different species onto a pasture. After cattle eat the rough growth, sheep will eat the lower grasses and legumes that the cattle cannot reach.
The methods depend on whether you have more money or more time. Instant pastures are expensive. If you're willing to spend a few years on the project, it can be done with minimal investment.
Start with a survey of the trees. There may be some trees you want to leave on an overgrown orchard, field, or woodlot, like old apple trees or ancient `wolf' trees on the edges of a field. Most animals enjoy fallen fruit (watch out for drunk sheep if the apples lie too long), and all animals need shade. You may be able to sell mature trees to a logger; otherwise, take advantage of the firewood. If you have access to a chipper, the slash can be chipped for garden mulch and as path coverings. Alternatives for the slash are burning (you'll probably need a permit), or piling in an out-of-the-way area as a wildlife refuge. It will eventually rot down.
The quick way to a pasture is to hire a bulldozer with a grubber blade, or a backhoe, to clear the stumps and stones. A grubber blade looks like a huge rake, and will clear out stumps and large stones without scraping away the topsoil. A good backhoe operator can also pull stumps and stones without disrupting too much of the topsoil. Some backhoe operators find it easier to pull stumps when the trees are left standing, by using leverage high up on the trunk. It may be wise to ask before you bring out the chainsaw. If you hire a bulldozer without a grubber blade, make sure the operator scrapes the topsoil aside before pulling stones and stumps, and regrades the topsoil afterwards.
If you have more patience than money, saw stumps parallel to the ground -- a sharp stump can wreak havoc with tractor tires or the feet of livestock -- and where possible, cut the stumps low enough to clear a mower, so you can clip the pasture even before the stumps rot. You may want to hire a backhoe or dozer to pull a few large stones, or learn to live with them. Lambs love a big stone or two for games.
You can cut brush low to the ground with a chainsaw, a saw-blade on a heavy-duty weed-whacker, a heavy-duty brush hog, or a hydroax (a super heavy-duty brush-hog mounted on an excavator). Be careful with light-duty brush hogs on heavy brush or a stony field, or saw-blades on lawn-trimmers. You may be able to scrape away some brush with a bucket-loader on a tractor, though most tractor loaders don't take kindly to being treated as a bulldozer. You may have to mow some brush repeatedly to eliminate the growth.
Sometimes, it is easiest to use animals to clear the brush. Goats are specialists, often preferring brush to grass and clover. Sheep love poison ivy and bittersweet, and will clean up leafy spurge, which has proved a problem in areas as widespread as the western range states and Rhode Island. The real masters of brush clearing are pigs, who will eat roots and all if they are put out without nose rings. The trick to getting animals to clear brush and weeds is to confine them to a relatively small area with a tether or temporary fences. If they have an entire pasture to roam, animals seek out tasty new grass, clover or buds. When they are confined to a small area, they eat everything in sight, including brush and weeds. One clever trick for stumps is to drill deep holes in the perimeter of the stump and fill them with corn grain; pigs will work until they have even a large stump out to get the last of the grain.
Watch out for poisonous plants when `mob stocking' a pasture to eliminate rough or unwanted growth: animals that are pressed may ingest plants that they would avoid under normal grazing conditions.
Once you have the trees and brush cleared, it's time to upgrade the pasture.
The greatest improvements to the soil and the pasture comes from careful and controlled grazing. The addition of animal manures and urine, and the regular `mowing' of the forage from livestock grazing in large enough numbers, will do wonders for a pasture. Sometimes, a few additional steps can help the animals do their job.
The first step is a soil test. In many areas of the country, pasture land has a pH too low to support the better forage grasses and legumes. The soil test -- make sure you specify the target forage when you turn in the sample -- will tell you how much lime to add. Some indicators of low pH in a pasture are the presence of wild strawberry plants, buckhorn plantain, red sorrel, moss on the soil surfaces, mole activity, the absence of quackgrass or bromegrass in well drained areas, and the absence of reed canary grass in poorly drained areas. In low pH soils, alfalfa will be stunted, with yellow leaves on the newer growth. Even if there are clear signs of low pH, a soil test will give a more precise guide to how much lime is needed.
If you cannot disc in the lime when it is applied, applications of more than two tons/acre may need to be split over a period of a year or so. You can spread lime yourself with a dump spreader (they're often available at auctions or used implement dealers), or a fertilizer spreader on a tractor, but it may be easier and cheaper to have a local blending plant spread it by truck. Spreading lime with a fertilizer spreader is a dusty job; if the lime isn't washed off carefully, the metal parts of the spreader will end up looking like swiss cheese. A disc harrow is ideal for incorporating lime, which is slow to migrate from the surface of the soil. A tractor-mounted tiller will also incorporate lime, but is slower to use, especially in soils with high clay content. Make sure the soil is relatively dry, especially if you are using a tiller instead of a disc harrow.
For low-input passive improvement, you can introduce clovers and other desirable forage species by feeding mature hay on the pastures. Small seeds, such as birdsfoot trefoil, can be added to grain or salt rations of animals. Seed can also be added to each load in the manure spreader, or broadcast in early spring or fall onto a heavily-grazed field. The animals will distribute seeds in their manure, and trample the seeds into the ground as they feed.
You can also change the balance between native clovers and grasses, or the mix of grasses in a pasture, by adjusting the formula and timing of fertilizer application, or by modifying the pH of the soil. Adding nitrogen-rich fertilizer, and early fertilizer application, favors grasses; heavier applications of potash and phosphate and later application favors the clovers. Higher pH from applied lime generally favors native clover and other legumes.
Timing your grazing and mowing can also improve the pasture. Grazing heavily early, when grasses come up before the legumes, will favor the legumes. Grazing heavily or mowing when jointed grasses like bromegrass have their growing point close to the ground will retard their growth. Alternately, if grasses are allowed to reach boot stage, when seed heads have formed inside the stems, cutting or grazing encourages rapid regrowth.
For more aggressive improvement, once you have the pH up where you want it -- usually close to neutral for alfalfa or clovers, a little lower for grasses -- you have a choice of reseeding from clean tillage or over-seeding. For lush mono-culture grass pastures, or for planting legumes like birdsfoot trefoil or alfalfa that don't compete well, in some areas clean tillage may be the only possibility. You may need to plow under the old turf; you will certainly need extensive discing. It's hard dusty work, and the animals will have no use of the pasture until the new seeding is well-established. In some cases you may have better results if you plant an interim crop before a final discing and seeding with the desired grass or legumes. Buckwheat that you can harrow in as green manure works well to choke out weeds, or you can plant dwarf Essex rape, turnips, oats or rye, and let your animals graze down the temporary pasture before a final seeding. Keep your animals off the newly seeded pasture until it is well established.
Many native grass pastures can be renovated without plowing and harrowing to clean tillage. Soil test results will tell you what fertilizer to apply for the new seeding. You can then over-seed with a no-till seeder (some agricultural extension offices rent or loan them), after killing the existing sod with RoundupTM or another herbicide, or grazing the sod down aggressively with mob stocking of sheep or pigs. Gramoxone (ParaquatTM) will provide a `burndown' of the existing vegetation without killing roots; this is a good solution for interseeding in an existing sod. if you don't have access to a no-till seeder, a few passes with a disc or a field cultivator will incorporate the fertilizer and lime, and disturb from 50% to 100% of the existing grasses. Lime and phosphorus input should come 6-12 months before seeding, if possible. If your soil has some clay content and shows frost cracks in late winter, you may not need to disc if you `frost seed' in late winter, after the snow is off but while the ground is still frozen. The same technique could be used in California to seed into the soil cracks at the end of a dry summer. Broadcast the new seed at a heavy rate and either roll, harrow lightly, or drag with branches or a wooden drag to set the seed. A temporary mob stocking with sheep will also set seed.
For grasses like bermudagrass that are planted from sprigs, you can either rent, borrow or purchase a sprigger (Bermuda King in Okarche, OK still makes them; ask for Richard Reynolds), or broadcast the springs and cut them in lightly with a disc harrow. The latter procedure is not as efficient, and may require a heavier coverage with the sprigs.
If you are seeding legumes to upgrade a pasture, when grass growth begins, and as soon as the soil is dry enough to avoid tracking, graze the newly seeded fields with enough animals to keep the grass short. This will open the field to provide light to the new legume seedings. If you cannot graze down the early grass with animals, you may have to mow it to allow light down to the legumes. Keep the animals on the pasture until you see them starting to eat the newly seeded legumes. Then pull the animals off and let the legumes grow undisturbed for 6-8 weeks for clovers, 8-12 weeks for alfalfa. At this stage, don't worry about the weeds; it's more important to get the new seedings established. When the legumes are vigorous, you can begin a regular grazing program.
Mono-culture grass pastures are sometimes used on picture-book horse farms, and mono-culture legumes are sometimes used for aggressively rotated paddocks or where a cutting of high quality hay is taken off the pasture in the spring. In general, the most productive and lowest maintenance improved pastures for ruminants are mixed legumes and grass. The advantage of mixing legumes and grass on a pasture is that the clover and grass grow at different times of year, providing good feed through the seasons. And once inoculated clover or other legumes are established, they will generate nitrogen that will in turn fertilize the grass -- saving the expense of added nitrogen fertilizer.
There is also some recent interest in the use of herbs in pasture mixes. Animals love the herbs, and some have beneficial medicinal properties, including serving as natural antithelmics. Chicory, lotus, garlic and parsley are favorites in New Zealand. Rosemary and garlic in the pastures would give you pre-seasoned lamb; it takes anywhere from a few weeks to a few months for flavors to begin to affect the meat (pine is quick, apple is slow). Be careful with herbs if you're using or selling the milk from your animals: Thomas Hardy's Far From the Madding Crowd is a good example of the perils of garlic in a pasture for dairy cattle. Most herbs cannot tolerate heavy grazing, and are best reserved for special paddocks that are grazed twice a year.
Typical legumes for pasture seeding are red, ladino, alsike, or white clover; birdsfoot trefoil; and alfalfa. The latter two are often tough to establish except in clean tillage. Alfalfa pastures require a fairly aggressive rotation scheme, and precautions so the animals will not bloat. Birdsfoot trefoil produces only about 80% of the dry-matter per acre of alfalfa, is slow-growing in the spring, and does not stand up well to continuous grazing, but it does not cause bloat, picky animals will consume more of the delicate stems than with alfalfa, it retains its palatability well when stockpiled for late season grazing, and it seems to do well in cooler climates. Use an upright variety of birdsfoot trefoil if you are also planning to cut hay from the field.
For renovation seeding, a combination of ladino and red clover works well in many areas. Red clover can handle shading by grasses better than most other clovers; ladino clover has small seeds that do well in partially tilled soils. Some tests have indicated that red clover can retard ovulation in ewes, so it may not be a good choice for a pasture used for flushing sheep before breeding. Red clover is also susceptible to a mold that causes photosensitivity and slobbering in equines. Some varieties of white clover grow too low to cut for hay, so it may not be a good choice on a pasture where you're planning to take an occasional cutting of hay. Alsike clover grows well on poorer soils, but is not recommended for equines. White clover tolerates close grazing and trampling well, and is a traditional companion seeding for bluegrass or perennial ryegrass. Make sure you inoculate legume seeds before seeding if they are not pre-inoculated.
Predominantly legume pastures present the potential danger of bloating in ruminants, and laminitis and/or founder in equines. Bloat can generally be avoided if you condition animals to lush legumes gradually. Let them eat their fill of dry hay in the morning before they go onto an alfalfa or clover pasture, and limit their grazing the first few days.
Among the grasses, orchardgrass, bromegrass, timothy, bluegrass, tall fescue, bermudagrass, and perennial ryegrass are all popular in pastures. Unless you've cleared to clean tillage, chances are your pasture will be a mixture of grasses. Some farms structure their grazing to provide a rotation between cool-season grasses (bluegrass, bromegrass), which do best in the spring and fall, and warm-season grasses like bermudagrass or sudangrass. There are many favorite combinations: bluegrass and white clover, perennial ryegrass and ladino clover, orchard grass and red/alsike clover. Local usage may suggest a combination for your area. If you are reconditioning several fields, you may get higher overall productivity by using different combinations in different fields, to take advantage of the different maturity dates of the various grasses.
Pasture seed companies like Hodder & Tolley in New Zealand and Cotswold Grass Seeds in Gloucestershire, UK have developed cultivars of permanent grasses with improved cool weather tolerance, to extend grazing seasons well into and in some areas right through the winter. There are also new cultivars of fescures and perennial ryegrass which tolerate continuous grazing far better than older varieties. Local seed catalogues are the best source of cultivars for your area; most large farm supplies like Agway and many of the seed companies have pasture seed catalogues. You may also be able to find recommendations for your locale on the Forage Information System. The alternative for extending grazing seasons is annuals.
To maintain their productivity, pastures need adequate nutrition, clipping or controlled grazing to eliminate weeds and over-ripe grass, and protection from overgrazing.
Fertilizers and added manure provide the nutrition. Trust your soil tests, but as a guideline, legume or mixed legume-grass pastures generally need 30-60 lbs of phosphate (P2O5) and 90-120 lbs of potash (K20) per acre once a year, with the lower rates for pastures where you spread manure or have fertile soils. Alfalfa and clover pastures, and grazing animals, may profit from small amounts of boron (~9 lbs/acre); because the amounts are small, the boron should be carefully mixed into the fertilizer before spreading. Good legume-grass pastures need no additional nitrogen (N). Straight grass pastures need 80-120 lbs of N per acre annually in split applications (usually a first application in early spring in the east, late fall in California, and a second application sometime after first cutting of hay in your area), with 40-90 lbs of P2O5 and 60-100 lbs. of K2O per acre annually. If you spread manure on the pasture, application rates as low as 40-60 lbs N, 20-30 lbs. P2O5, and 30-40 lbs K2O are probably sufficient. Taller grasses, like orchardgrass and reed canarygrass, generally need the higher rates.
If you don't have access to a blending plant, or don't have the equipment to use bulk fertilizer, you may have to select from available bagged fertilizer, or mix two or more blends of bagged fertilizer to get the formulation you need. A good starting point for legume or mixed legume/grass pasture is 300-600 lbs/acre of 0-10-40 or 0-15-30. A starting point for grass pastures is a split application of 400-600 lbs/acre of 15-8-12.
Applied manure, in addition to the animal droppings, is good for a pasture. Ten tons per acre of cow manure (two-thirds that amount of sheep manure), well-flailed and spread after grazing has stopped (late fall in the east), is ideal. Chicken manure application should be no more than 3-4 tons per acre. If you don't have a manure spreader, you may be able to borrow one, or hire a neighbor to custom spread your manure. If you have problems with parasite worms in your livestock, it may help to compost the manure thoroughly before applying it.
Unless you are using a very aggressive rotation scheme on small paddocks, you will probably need to clip your pastures at least once per year to control weeds. Twice is better -- once around the time of first cutting of hay to eliminate ungrazed old growth, and a second mowing late in the growing season to get the weeds. Pastures with tall-growing grasses like orchardgrass or reed canarygrass may need three clippings per year. Some livestock, like horses, are selective eaters; they won't graze near deposits of horse manure or eat weeds, so an untended pasture soon consists of rank areas with eaten down grass inbetween. Domesticated deer will graze the legumes and herbs heavily and leave rank growth of grass. Frequent clipping will restore the health of these pastures by eliminating the woody overgrowth and providing palatable fresh growth. Even on heavily rotated paddocks, clipping after each rotation can do wonders to eliminate nasty weeds like thistles.
Timing is all-important when you are mowing to eliminate weeds. You want to hit them before they produce seeds. Mow too late, and your brush hog will actually distribute the weed seeds in your pasture.
A sickle bar mower set at 3 inches will do an excellent job of clipping a pasture. See the Haying FAQ for information on adjusting a sickle bar mower. A brush hog will also do a good job if the blades are sharp; on a stony pasture, the brush hog will function as a missile launcher, so be careful. Flail mowers do a good job on stony pastures. If your pastures are free of stumps and stones, you can use a heavy-duty finishing mower or lawn mower. For smaller pastures, a walk-behind sickle-bar or DR-style mower will do a fine job of clipping. The best time to mow is just after a heavy grazing cycle. Some mowers may scatter the manure, or you can use a spike harrow or drag to break up and distribute clumps of manure. An alternative or supplement to mowing is a wether goat or two in with your other animals, if you've got the fences and secure enough gates to hold a goat.
Grazing too early or late in the growing season takes a toll on a pasture. When a pasture is grazed too early, the young shoots are quickly nibbled off, plant root systems are destroyed, and weeds move in. Animals then churn the wet sod searching for palatable plants, turning the pasture into a muddy, eroding feedlot. Grazing too late strips the growth that forage grasses and legumes need to build up root systems during the winter or dormant season. Fields reserved for succession grazing on annuals can extend the grazing season.
Fences have two purposes: keeping animals in and keeping predators out. The wood fences of fancy horse farms or New England stone walls may succeed at the former, unless you're trying to keep a bull away from cows in season, or unweaned lambs away from their mothers. To keep predators out, you will probably need woven wire, high-tension, or electric fences. Stopping a mother coyote who is trying to feed her kit may require 48-inch woven wire with additional strands of barbed wire at ground level and above the woven wire, or 6-7 strands of high-tension electric fencing.
Cattle and horses that are trained well to electric fences can be fenced in with a single wire. Many horse farms prefer to use a highly visible wire or one of the wide braided conductors. Smaller animals and animals with heavy coats need multi-wire fences to contain them, and pigs need carefully-placed ground level wires -- barbed or electric -- to keep them from digging their way out.
Woven wire fences are relatively simple to install. Depending on local supplies and aesthetic needs, you can use metal T-posts, pressure-treated commercial posts, or homemade posts of a resistant wood like cedar or locust. T-posts or sharpened wooden posts can be started with a pry bar and driven in with a post pounder. Corner posts should be stout, dug deep and may need braces. Use a fence-stretcher or a tractor to tension the fence before you staple it to the posts, and leave the staples loose on intermediate posts to allow the fence some play. A convenient tool for fence-stretching is a pair of 2 x 6 boards, longer than the height of the fence, drilled for 3 to 5 strong bolts. Sandwich the end of the fence between the two boards and tighten the bolts to hold the fence, then hitch a chain from the tractor or fence stretcher to the sandwich-boards to stretch the fence evenly. The newer high-tension woven wire makes a neat fence on level ground with fewer intermediate posts.
High-tension fences work best for long runs on level land, where they require few intermediate posts. Because of the tension in the wires, the corner posts need to be well dug and braced; old telephone poles can be cut up to make good corner posts. In some cases high tension fences do not need to be electrified, but to look good and perform well, they require careful installation and no stinting on tensioners and other hardware.
For temporary fencing, portable electric fences using `polywire' or electrified netting are quick to set up and move. The various reel devices are useful if you plan to move the fence often. Gallagher sells hardwood posts that require no insulators, at least in relatively dry climates, which are convenient as end and corner posts for temporary electric fences. Welded hog or cattle panels can also be used for temporary holding pens.
Electrified scare wires, generally 6-8 inches off the ground, and at the top, or on offset brackets, can be used as an adjunct to stone walls, woven-wire, or wooden fences to deter predators.
Premier Fence Systems (800.282.6631, fax 319.653.6304), Gallagher (usa 210.494.5211, nz 07 838 9800) and Kencove (800.245.6902, fax 412.459.9148) distribute catalogs with excellent ideas for electric and high-tension fencing. Reliable electric fences require adequate charger strength, good grounds, and some thought to gateways, streams, and abrupt changes in terrain.
Animals on pasture need a supply of clean water and salt. A running brook or stream in a pasture can supply water, although it is sometimes difficult to keep animals from trampling and fouling the banks of a stream or pond. In general, sheep, which prefer dry upland grazing areas, will do less damage to stream or pond banks than cattle. If you don't have a natural supply of water, you will need a watering tank, and possibly equipment to keep the water supply frost-free in the winter.
You can supply water with buried pipe, hoses or surface-level pipes in summer or in areas with mild winters, or by hauling water. PVC pipe buried below the frost-line and frost-free hydrants are the most reliable, but in stony soils it can be a real chore to bury long lengths of pipe. A rented ditch-witch will do the job in stone-free soils; otherwise you may need a backhoe.
You can haul water in everything from empty garbage cans in the back of a pickup to special pickup-bed tanks to water trucks. In some situations it may be better to bring the animals to the water daily or every other day instead of hauling water.
Keeping water frost-free in the winter is a challenge. Floating electric heaters work, but they are expensive to operate, and if the water level drops low, they can burn through rubber or plastic water tanks. The submersible heaters are safer. Some tanks, like the Rubbermaid units, have provisions for heaters that fit in the drain holes. For any electric heater, the exterior outlet should be a GFCI, and any extension cords should be rated for the heater load and for exterior use. Use shrink-wrap tubing or plastic electrical tape around the junction of the electrical cords. It is a good idea to have some sort of indicator light on the GFCI outlet, in case it trips.
Insulating a tank and leaving a hole only large enough for the animals to reach the water can save on water heating bills. There are also donut-shaped devices that sit in the bottom of a tank and release a regulated stream of propane bubbles to keep a tank frost-free; a five-gallon tank of propane will power one for up to two months.
One alternative to heating water is the insulated waterers like the Mirafont or the pasture waterer sold in the NASCO catalog; these waterers rely on enough animal population using the waterer to keep the water flowing. Too few animals and the waterer will freeze up.
Another option, if your winters aren't too cold, is to set waterers into holes lined with manure or a manure and hay/straw mix. Heat from the composting manure will keep the water thawed. Rubber or plastic 55-gallon drums cut in half are good for these naturally heated waterers. You can break up surface icing with a stick, and if it isn't too deep the animals will break it with their noses or hot breath.
Along with water, animals need salt. Often TM (trace mineral) salt is used to supply additional minerals, or minerals are added to the salt to supplement the regular diet. Salt blocks are popular for cattle. Loose salt works better for sheep. You may want to speak with your local veterinarian or local producers, and possibly test your forage and grain, before adding minerals or using a TM salt. The line between minimal requirements and toxicity is a fine one for many minerals, especially copper and selenium.
Some pasture forages, such as alfalfa, birdsfoot trefoil, or timothy, require a period of rest after a period of heavy grazing. Many other forage species also respond well to alternating cycles of grazing and rest. Most grazing animals, when they are confined to a limited area, will eat everything in sight, including weeds and coarse forage, instead of nibbling only the tender shoots that grew the night before. Rotation grazing takes advantage of these patterns of forage growth and animal habits to increase pasture productivity.
Rotation patterns can vary from super-aggressive `forward paddock grazing' which may move the animals daily, to a casual rotation between two pastures every three or four weeks. Two weeks is generally the minimum rest for a pasture; three or four weeks is better. Some farms rotate different livestock onto pastures in sequence, taking advantage of the different grazing habits of cattle and sheep. After the cattle eat the coarse growth, sheep are brought in to eat the fine grasses and clovers the cattle missed.
Livestock can be rotated between separate pastures, or between paddocks carved out of pasture areas with stone walls, cross-fencing, or portable electric fencing. Portable fencing is versatile, but requires more work to move and set up than the advertisements in the catalogs and magazines suggest. The alternative of permanently divided paddocks can be inconvenient for mowing, fertilizing, or taking an occasional cutting of hay. Whatever the rotation pattern, you will need shade, water, and mineral feeders in each paddock or pasture area; if you don't use portable fencing, you will need gates or bar-ways between the paddocks or pastures. Some farms save water piping and labor by arranging their paddocks around central islands with waterers and mineral/salt feeders; by opening and closing two gates, or moving a hog or cattle panel, they can rotate the stock to a new paddock.
Strip grazing (sometimes called the Voisin system) uses one or two electric fences, moved as often as daily, to allow the livestock to graze fresh forage. On some operations, the lambs or calves are allowed to graze a paddock or strip first; when they move on to fresher grass and clover, the ewes or cows are brought in to clean up the old paddock.
A few cautions: some forages, like bermudagrass and tall fescue, show little or no response to rotational grazing. And recent research suggests that rotation does not help with parasite control unless the animals are wormed frequently enough to keep the parasite populations low. The typical rotation periods of 2-6 weeks are not long enough for the parasitic organisms in the idle pasture to die, and the longer ungrazed growth of an idle pasture may actually shelter parasites from sunlight. A field generally will not be parasite-free unless the animals have been off it for a full year. In many situations, overall production (weight gains, milk production) from rotational grazing do not exceed production from continuous grazing of the same amount of land. Excessive pressure on forage, when animals are forced to consume all of the forage, can actually lead to significant drops in production.
But, if your pastures are predominantly alfalfa or timothy, or if animal management needs such as predator control make it advisable to confine the flock or herd to smaller pastures, or if you are using animals to aid in the improvement of pasture by forcing them to graze areas hard, rotation grazing can do wonders for your pastures.
Before rotation onto a clean pasture is an optimum time to worm your animals. Even if you don't have a planned rotation scheme, when you see animals moving about restlessly in search of forage, it may mean the pasture is temporarily exhausted and needs a rest. If you don't have an alternate pasture, it may be time to confine the stock to a feedlot until the pasture recovers, or at least to take pressure off the pasture by feeding supplementary hay or silage.
You can extend the grazing season, and gain maximum production (milk from cows, growth in lambs) by rotating stock to different forage depending on the season. On permanent pastures, you could rotate between grasses that grow better in the spring and fall (bluegrass, bromegrass) and mid-summer grasses (bermudagrass). You can also rest pastures by turning animals into hayfields to clean up the aftermath. Some old-time dairy farmers developed sophisticated grazing programs to take advantage of the growth patterns of a variety of forage, and may be a good source of advice. One caution: ruminants and equines may develop scours when they are moved abruptly from one forage variety to another; it is generally a temporary condition and disappears when the stomach flora adapt to the new forage.
You can also extend the grazing season by reserving a field or portion of a field for annual plantings of supplemental grazing crops. Winter rye and/or wheat seeded in the fall can provide early spring grazing before the permanent pastures are ready. Oats seeded in the spring can provide grazing in the summer when regular pasture growth slows. On heavier soils, Japanese millet can provide mid- to late-summer grazing. Brassicas like rape or turnips can provide temporary grazing in 4 to 6 weeks, and allow grazing well into the winter. Some brassicas can be heavily grazed, rested for a month, and grazed again. Sheep will trample and waste root crops if they aren`t confined to a few days worth of grazing with temporary fencing, and sometimes sheep need an experienced lead animal to show them how to eat root crops.
Some varieties of brassicas (turnips, rape, kale) contain high levels of certain glucosinolates, which under some conditions will cause goiter in sheep or cattle by interfering with thyroid function or iodine uptake by the thyroid. As a precaution, make sure animals on brassica pastures have access to a trace mineral salt containing iodine, and that they are consuming the salt.
Supplemental pastures and/or grazing hay aftermath may allow you to bank grass (field hay) on your permanent pastures for late season grazing. Temporary fencing may be useful; you can put up fences even on frozen ground by using small round fiberglass posts, and drilling holes in the ground with a battery-operated drill. A fall application of nitrogen fertilizer (~60lbs/acre) will green up the grass; sheep and cattle can graze snow-covered pastures as long as there is no heavy icing. Even mixed grass/clover pastures which generate their own nitrogen during the growing season can sometimes profit from a fall application of nitrogen to encourage grasses like perennial ryegrass over early-dormant, low-nutrition grasses like redtop. Unfertilized banked pasture is generally low nutrition feed. If the quality falls below the 45% IVDMD (In Vitro Dry Matter Digestability) of good hay, the animals may need relatively expensive supplements of grain or silage.
In some cases, aftermath grazing can have additional benefits. Grazing aftermath alfalfa (after the first frost) will often control or reduce the population of alfalfa weevils. And a concentrated grazing period on any crop aftermath will add useful manure to the soil. To avoid weed seeds in aftermath-grazed hayfields, it is a good idea to isolate the livestock for 3-5 days after they come off a weedy pasture.
It is also possible to round-bale excess growth and leave the haybales in place behind fences, covered, or just on the field. When the animals have exhausted the fresh growth they will turn to the baled hay, even in heavy snow. See the Haying FAQ for more information on combined grazing and forage schemes.
With carefully planned succession grazing, rotation of permanent pastures, fall nitrogen application, and banked grass, it is possible to extend the grazing season to as long as 10.5 months in a climate like Wisconsin, and possibly to all year in milder climates. The trade-off for the elimination of manure and hay handling is the time, fuel and cost of harrowing, seeding and fertilizing supplementary grazing crops.
Mowing is often sufficient to control weeds. Goats or sheep can be effective `mowers' for weeds like poison ivy, bittersweet, or leafy spurge. At Maple Lawn Farm, our flock of Cotswolds have gradually eliminated poison ivy and bittersweet from our pastures, including infestations of bittersweet that completely covered stone walls. Mixed grazing, of sheep and cattle, or even sheep or goats with equines, can do much to control weedy growth.
For hard-to-mow nasties like Canada Thistles, it sometimes works to walk the field with a scythe or a metal-bladed weed-whacker. If you can rotate your livestock off the field for periods, you can use herbicides, either broad-spectrum or targeted, against weeds. BanvelTM, CurtailTM, CrossbowTM or Weed-B-GoneTM will attack broadleaf weeds without killing the pasture grasses; it is best to apply these broadleaf herbicides when the grass is not stressed, and when plants are building up their root systems. Fall, after the second or third cutting of hay in your area, is a good time.
If the weedy patches are limited, you can apply RoundupTM or another broad-spectrum herbicide by spot-spraying or by using a cotton glove over a rubber glove and rubbing the herbicide on the weed leaves by hand. Or you can build a wick applicator from a handle-length of PVC pipe, stoppers, and a length of canvas soaker hose. Cement a 45o elbow and an extension to the bottom of the handle pipe, and end with a stopper with a small hole at the bottom to seep the herbicide onto the canvas soaker hose that is tied over the end of the pipe. Fill the pipe with herbicide and stopper the top. You need to swing the pipe around a few times to start the wicking action. Then walk the field, carefully wiping the herbicide onto the weeds. John Maddock <Richard_Maddock@burnout.apana.org.au> is now marketing a Weedswiper, which uses a hydrostat to electronically monitor and control the supply of herbicide to the pad.
For large pastures and/or heavy infestations of weeds, you can use a tractor or truck mounted boom-sprayer, or hire a custom operator, to spray the herbicide. An alternative for selectively applying herbicides is to use knotted cotton cords dangling from holes in a length of PVC pipe that is mounted on a 3pt hitch or bucket loader. Cap both ends of the PVC pipe, fill it with herbicide, then adjust the height of the rig so the knotted cords drag against the weedy growth but miss the grass and clovers as you drive over the field. For a large field, you can rig a tank and piping to automatically refill the PVC pipe with herbicide. Weeds with persistent root systems, like bindweed or poison ivy, may require repeated herbicide treatments.
For areas that are infested with foxtails, barnyard grass, or other undesirable grasses, there is sometimes no alternative to discing and reseeding an area of the pasture. We've had good luck at Maple Lawn Farm harrowing up the weedy area after the spring flush, late-summer seeding a mixture of dwarf essex rape and winter rye, and using temporary fences to keep the stock off until the regular pastures are exhausted in late October or November. We then strip graze the rape and winter rye, which extends our grazing season for another month or so. In the spring, we let the stock graze down the early regrowth of winter rye, then harrow and seed oats in the early spring, graze the oats down in mid-summer, and finally harrow and seed a permanent grass and clover mix in late August or early September. The repeated discing and alternate plantings gets rid of the obnoxious stuff without taking away valuable pasturing acreage.
The major potential disadvantages to pastures are predators, parasites, and poisonous or toxic plants. The Predator FAQ includes suggestions on how to control the impact of predators. Parasites, especially worms, are a challenge in any grazed area. Long-term rotation, regular programs with antithelmics, careful monitoring of your livestock, and periodic testing and inspection of feces will usually keep parasites under control. If worms are a severe problem, or in cases like meningeal worms (Parelaphostrongylus tenuis, normally hosted in white-tailed deer), where a small infestation of worms can kill sheep, llamas or goats, it may help to fence off swampy areas of a pasture, and/or keep livestock off the pasture in the evening and early morning hours when snails or other worm hosts, and worm larvae, are active on the dew-damp grass.
In general, the only way to guarantee a worm-free pasture is to keep the livestock off for a full year, either by rotating another species (for example, cows instead of sheep) onto the land, or by putting the land into hay or another crop. Except in cases of severe infestations or aggravating circumstances, a regular schedule of antithelmics, rotation, and clipping to allow sunlight into the grass after each rotation will control parasite populations.
Some tall fescue pastures, appealing because of the high forage yields, long growing season, and minimal management required, produce disappointing growth in livestock. The problem is `fescue toxicosis,' caused by a fungus named Acremonium coenophalium (earlier identified as Epichloe typhina) which infects as much as 95% of tall fescue pastures in the US. Some symptoms of `fescue toxicosis' include rough hair coats, excessive nervousness, salivation, lameness, low tolerance for hot weather, constant low-grade fever, reproductive problems, abortions, and stillbirths. The fungus is carried in the fescue seed, and the presence seems to correlate with increased levels of naturally occuring alkaloids. There are new cultivars of Kenhy, Johnstone, and Triumph tall fescue available from fungus-free seeds. Reseeding a stand of infected fescue will probably require a plow-down or broad-spectrum herbicide and and interim crop.
In some cases, meat animals fattened on green pasture develop a yellowish tinge to their fat from the stored carotene. Some packers will reject meat with yellow fat. Restaurants and private customers may prefer the grass-fed meat, not only for the taste and texture, but because pasture-fattened animals tend to have less marbling; the fat is on the edge of cuts and easily removed. If your market is to packers who reject yellow-tinged fat, finishing the animals on a feedlot for 60 days, or grazing for a few months after the green flush of spring pasture, will bring back the snow-white fat.
You can, and if there are no poisonous plants or other dangers, the animals will browse grass and brush. Some species to watch out for: choke cherry and elderberry (the leaves are toxic if a branch is cut or knocked down by a storm), water hemlock, spotted hemlock, rhododendron, locoweed, lupine weed, jimson weed, horsenettle (nightshade), milkweed, and some laurels. The bark of black locust is poisonous to cattle. Western nasties include fiddleneck, brackenfern, larkspur, tansy, and yellow star thistle. Your local Agricultural Extension office will probably have brochures and charts to identify noxious and poisonous plants in your area. Most stock will avoid poisonous plants unless they are hungry; be careful in dry periods, or when you are mob stocking to improve a pasture. For more details on poisonous plants which affect livestock, see the Canadian Animals poisoned by plants site.
Unimproved pasture like woodlots or brushy slopes generally won't provide more than maintenance feed for cattle or sheep. But if you already have a regular feeding program and need only supplemental grazing, or if you are using animals to maintain the land, low-input grazing may be just the ticket. On some farms, feeding supplementary grain to animals on unimproved pasture may be more practical than improving pastures with heavy inputs of lime, fertilizer, and tractor time.
Ronald Florence, who raises Cotswold sheep in Stonington, Connecticut and provides agricultural consulting services, is the author. Additional information was provided by
This document is copyright 1994-97 by Ronald Florence. Permission is granted to copy this document in electronic form, or to print it for personal use, provided that this copyright notice is not removed or altered. No portion of this work may be sold, by itself or as part of a larger work, without the express written permission of the author; this restriction includes but is not limited to print, digital media, and electronic transmission.
The current html original of this document is available, along with html FAQs on lambing, predators, and haying, on the Maple Lawn Farm home page at http://www.connix.com/~mlfarm. An ascii-digest version is posted by script every 60 days to Usenet newsgroups misc.rural, misc.answers, and news.answers.
Please send comments to Ronald Florence <email@example.com> Last modified: Thu Mar 13 16:28:43 EST 1997