Cart

Soil Health Resource Guide

#forbs

By January 15, 2018January 29th, 2018No Comments

Jump to Article:

Ley Farming (including perennial pasture in the crop rotation)

By Dale Strickler

One of the main purposes people have for planting cover crops is the desire to improve their soil. It has been observed that most of the soil improvement from a cover crop comes from the roots rather than the tops.  Not only do roots provide a source of organic matter themselves, but they also provide exudates that nourish soil microbes.  Obviously, more root mass means more potential organic matter and more root exudates.  This has led many cover croppers to seek plants with greater root mass, and this has led them to experiment with perennials.  Perennials have much greater root systems than annuals, and their root systems live for 12 months a year rather than 4 or 5, meaning there will be a much greater amount of root exudates.  As an example, corn will have a root system that will weigh from 3000 to 4000 pounds per acre which lives for roughly four months, while native prairie grasses will have from 15,000 to 30,000 pounds of roots per acre which live year around.  This indicates that the perennial might create as much as ten times the soil improvement in a year as an annual cover crop.  This comes as no surprise, most people are well aware that perennials improve soil to a great degree. Crops following a pastured, perennial sod typically yield 20-30% better than the same crops in a typical rotation. However, there are very few people who are willing to plant cropland to perennial forages, usually because they believe that perennials are an unprofitable use of cropland and because they believe that perennials take several years to establish.  While there are plenty of observations that would lead to those two notions, neither are a foregone conclusion. In fact, by understanding the limiting factors to establishment and pasture production, it is quite possible to both rapidly establish perennials, and to create a perennial mixture that can often create more income from livestock grazing than grain crops at normal yields.

   First, let’s explore why people believe pasture is an unprofitable use of land compared to grain crops.  Any land still in pasture is probably in pasture because it was too rocky, too erosive, or too something to be plowed to raise grain crops. As a result, we compare the productivity of pasture on poor land, to cropland on the best land. We also look at the productivity of crops that have had the benefit of fertilizer, herbicides, insecticides, hybrid genetically modified seed, all planted and harvested at the optimum time, and compare this to the productivity of pasture that has had no inputs and little management.  What if we had pastures with top-notch pasture species that received top-notch management? The average pasture produces about 50 pounds of beef per acre per year. The top recorded yield in the US for beef production per acre is 1458 pounds of beef per acre, on a patch of rainfed pasture in Kentucky.  That is almost 30 times the average! Obviously, there is a lot of room for improvement in our pasture management, and if we do so, there is also great potential for vastly increased profit.

   Secondly, the slow rate of establishment can be overcome with an understanding of soil biology. It has been recently discovered that the slow rate of establishment of many perennial species is due to the lack of good soil biology, particularly mycorrhizal fungi. Mycorrhizal fungi attach to the tiny roots of perennial seedlings and help them access water and nutrients, thus greatly speeding establishment and development.  Research from Kansas State University with big bluestem has shown that inoculating seedlings with mycorrhizal fungi can increase seedling year biomass tremendously. (see below)

Biomass @14 weeks, avg 10 soils

No fert, no myco .187 grams
No fert, + myco 3.124 grams
N +K fert, no myco 1.04 grams
N + K fert, + myco 6.44 grams

   A good way to boost perennial success is to plant into a nice mulch of cover crop, which has been inoculated with mycorrhizal fungi to build a good hyphal network before the perennial begins to sprout.

Warm-Season versus Cool-Season Sods

   When it comes to soil improvement, native warm-season grasses are likely the best plants there are. They not only have a very high photosynthetic rate, but also allocate a very high percentage of their resources to root development. They are very efficient at using both water and nitrogen. However, they have a relatively short growing period and have less forage quality than cool-season grasses when both are mature. The short growing season can be extended by including other forages in the mixture, like cool-season legumes.

   Cool-season grasses have a longer growing season, are easier to establish, and are higher in protein and digestibility than warm-season grasses, but are not productive during droughts and are less nitrogen efficient. They usually have much less root volume than warm-season natives, and thus offer less soil improvement potential, but due to their faster establishment may have a nice fit when it is desired to insert a sod of only a few years duration.

   What about having both warm and cool season grasses in the same pasture? Historically, this has been discouraged, because the cool-season grasses usually end up dominating the mix eventually while the more expensive warm-season species end up not contributing over time. However, most of these observations have been with traditional continuous grazing. By utilizing adaptive management grazing using daily livestock moves and leaving tall residual heights upon exiting a paddock, it may just be possible to realize the advantages of both in the same pasture.

Diversity of Species versus Grass Monoculture

   While it is an option to just plant an all grass pasture, it is not advisable. Adding legumes can add vital nitrogen to the system, increase protein and calcium in the livestock diet, diversify the mixture, and add taproots to the soil profile.  Adding forbs may be just as beneficial, for several reasons. Early British authors who promoted ley farming stressed the importance of including deep-rooted forbs in pasture seedings.  The forbs tend to be deeper rooted than either grasses or legumes, which helps add drought tolerance to the pasture mix. Scientists have documented that deep-rooted forbs pull water from deep in the profile during the day, and then at night they leak some of this water into the topsoil to the benefit of their shallow rooted neighbors. Forbs often have much higher mineral content than other pasture plants. The following table illustrates the much higher content of phosphorus, copper and zinc (all minerals usually deemed necessary to supply by mineral supplements) of the forbs chicory and plantain than either perennial ryegrass or white clover.

Beef cow need .40 10.0 30.0        Perennial ryegrass .37 7.9 22.0White clover .35 8.6 22.0Chicory .66 18.6 57.7Plantain .48 15.1 37.7

%Phosphorus

Copper, ppm

Zinc, ppm

Beef Cows Need: ,40 10.0 30.0
Perennial Ryegrass .37 7.9 22.0
White Clover .35 8.6 22.0
 Chicory .66 18.6   57.7
 Plantain  .48 15.1  37.7

   Many forbs also contain compounds that confer other benefits. Plantain, for example, contains potent antimicrobial compounds that not only aid in fighting infections, but also acts similarly in the rumen to an ionophore like Rumensin to reduce methane emissions and improve feed efficiency. Chicory contains compounds that not only help counteract the bloat causing compounds in legumes, but also reduce intestinal parasites.

Making a Mixture

   A good pasture mix should include grasses, legumes, forbs, and the all important mycorrhizal fungi to maximize pasture production, animal performance and soil benefits. Here are a few of the more promising species for seeding ley pastures:  Warm-season grassesThe most promising perennial warm-season perennial grass appears to be eastern gamagrass. Gamagrass is not only the most productive of the native grasses but also appears to be the best soil improver as well. Additionally, gamagrass possesses unusual shade tolerance for a warm-season grass, which allows it to be established under a canopy of a corn crop, which can act to cash flow the establishment year.  Gamagrass teams well with several other forages, including alfalfa and birdsfoot trefoil for nitrogen fixation, and such a mixture can produce more than five tons of forage an acre. Gamagrass has a reputation for being slow to establish, but it has been learned that inoculation with mycorrhizal fungi greatly speeds establishment.

   Cool-season perennial grasses for rapid establishment, short term leys. These species establish rapidly, but typically only live a few years. They can be used either for short term stands, or in mixtures with longer lived species to boost production in early years of a stand, then gradually give way to the more permanent species.

   Matua bromegrass is a rapid establishing, short-lived, highly palatable grass. It maintains palatability after heading better than almost any other grass. Despite its short lifespan, it is quite drought tolerant relative to other cool-season grasses. It also reseeds quite readily.

   Perennial ryegrass has a higher sugar content than any other perennial grass, making it very useful for enterprises that require a high plane of nutrition, such as grass finishing or pastured dairy.  Perennial ryegrass is very tolerant of grazing pressure, but is susceptible to winterkill in northern regions and is also very susceptible to drought and heat. It is one of the few perennial grasses that establish easily from broadcasting.  Perennial ryegrass is long-lived in areas of cool, moist summers and mild winters, but is short-lived in areas of hot, dry summers or severe winters.

   Festulolium is a hybrid between fescue and ryegrass. It has some of the toughness of fescue, with the high quality of ryegrass. It exhibits hybrid vigor, with exceptional early yields, but usually only lives two to three years.

Cool-Season Grasses for Longer Term Leys

   Orchardgrass is one of the higher yielding cool-season grass species. It is a bunchgrass, which makes it less competitive against other plants in the mixture than sod formers. It yields best when there is an abundant supply of nitrogen and water, which makes it a top choice in irrigated pastures or good soils. Orchardgrass regrows well after grazing.

   Smooth bromegrass is a sod-forming grass that yields well in spring, but it has poor regrowth after grazing and does not produce well after the spring flush of growth.  It tends to spread and thicken over time if grazing pressure is not too severe, making it most desirable when a stand of long duration is desired, especially if included at low rates initially. Smooth bromegrass is also one of the more drought tolerant cool-season grasses.

   Intermediate and pubescent wheatgrass are high yielding but rather coarse and less palatable compared to other common pasture grasses. These two wheatgrasses are probably the most drought tolerant of the commonly seeded pasture grasses.  They are strong bunchgrasses and make for a very open sod, which can be filled with other species.

   Tall fescue has a very poor reputation because most of the fescue in the country is infected with an endophyte fungus that causes the plant to produce toxic alkaloids. The fungus makes the plant more tolerant of heat and drought, however, so it has redeeming qualities. Fungus free fescue varieties are available, but lack heat and drought tolerance. Now there are varieties available that contain an endophyte fungus that confers heat and drought tolerance, but does not produce toxins. These varieties, called novel endophyte, are the only recommended tall fescue varieties for planting new pastures. Tall fescue maintains its quality throughout the winter better than any other grass species, making it exceptional for stockpiling the summer and fall growth and grazing in winter. It is a bunchgrass, but tends to form a tight sod that holds up well to hoof and vehicle traffic.

   Meadow brome is closely related to smooth brome and resembles it, but behaves quite differently. It is a bunchgrass, and regrows very well after grazing, similar to orchardgrass, but is somewhat more palatable than orchardgrass.  It has much better summer and fall production than smooth brome.

Legumes

   Alfalfa is the most productive legume in most situations, is deep rooted and thus very drought tolerant, and has a high rate of nitrogen fixation. It is very bloat conducive, and also intolerant of continuous grazing, requiring bloat control measures and rotational grazing.  Alfalfa also requires deep, well-drained soils of neutral pH.

   Red clover is often the next most productive legume after alfalfa. Individual plants usually only live for two to three years, but red clover readily reseeds if rested long enough to make ripe seed pods. It is more tolerant of poor drainage and acidity than alfalfa, and also much less prone to cause bloat. Like alfalfa, it performs best with rotational grazing.

   Ladino clover is a giant strain of white clover. It is a low growing, long lived legume of exceptionally high quality and high palatability. It is also tolerant of hard grazing, even continuous grazing, but has shallow roots and lacks tolerance to heat and drought. It performs best in mixtures with more drought tolerant species of higher productivity. It spreads by stolons (runners) and fills in gaps between bunchgrasses and crowns of clumpy species like alfalfa.

   Aberlasting (white x Caucasian hybrid) clover combines the best qualities of ladino clover with the deeper roots, higher yield, and better drought tolerance of Caucasian (kura) clover. It is new on the market but appears to be a dominant variety.

   Birdsfoot trefoil is a nonbloating legume of exceptional forage quality. Trefoil contains condensed tannins that help control bloat. Canadian research has shown that if birdsfoot trefoil is over 10% of the diet, bloat is not an issue, even if alfalfa is the other 90%. It is only about half as productive as alfalfa, but is much more tolerant of poor drainage and acidic soils. Individual plants are not very long lived and so trefoil should occasionally be allowed to reseed for best persistence of the stand. Trefoil plants maintain good quality after maturity, so even a stand with mature seed is very palatable.

   Sainfoin is a tall growing, thick stemmed legume that may get four feet tall in spring, topped with beautiful clusters of pink flowers relished by bees and butterflies. It is highly palatable, with even the thick stems being readily consumed. It also contains condensed tannins, and performs similarly to trefoil in preventing bloat. It is very intolerant of poor drainage and acid soil, but does exceptionally well on poor, rocky upland soils with high amounts of limestone.

Forbs

   Chicory is a very deep-rooted forb that is highly palatable in the vegetative stage, and possesses both a very high content of necessary minerals and compounds that help reduce parasitic intestinal nematodes. It resembles a large dandelion when vegetative, and shoots up a coarse flowering stalk topped with blue flowers when it becomes reproductive.

   Plantain is a low, growing, leafy forb with beneficial mineral content and antimicrobial properties. It is highly palatable, and regrows well after grazing.

   Burnet is a low- growing forb that appears to maintain quality all year long, remaining green even in the dead of winter and heat of summer. It is deep-rooted and is one of the most drought tolerant of the commercially available pasture species.

Back to top ↑

Ley Farming:
the fast track to soil improvement

By Dale Strickler

Just a few years ago, the idea of cover crops seemed rather radical to many folks. Planting a crop for the primary purpose of soil improvement was considered a waste of money by most people in agriculture. Over time, however, those who persisted with cover cropping began to notice ever-increasing soil quality that was reflected in higher yielding crops with fewer inputs, along with a whole host of other benefits.  These benefits in soil quality arose partially by better residue cover, but largely due to the additional root mass provided by the cover crops. The roots of the cover crops improved soil aggregation, provided root channels for improved rainfall infiltration, and gave off exudates that fed soil microbiology.

The observation that root mass is a large part of the cover crop benefit has led many innovative farmers to search for plants with much larger and more vigorous root systems than any of our commonly used cover crops, and that has led them to experiment with perennial plants.

It seems like we often have to reinvent the wheel, and this realization that perennial plants improve soil much faster than annuals has had to be “re-discovered” over and over throughout history.  British agriculture authors such as Sir Robert Elliot (he was knighted in the days when you had to make a bigger contribution to society than writing a popular song) in the late 1800’s advocated the rotation of crops with perennial pasture sods, as did George Stapleton and Newman Turner right after World War II. These authors promoted what was called an “herbal ley”, or a short-term perennial pasture composed not just of grasses, but also of nitrogen fixing legumes and mineral-rich forbs, with deep roots to bore holes through compacted plowpans.   For your convenience and further education, the writings of these authors can be found by following this link: Journey to Forever | Online Library

The root system of a perennial plant simply dwarfs that of an annual. Here is a photo from the Land Institute that compares the root systems of wheat (to the left of each month) with that of the closely related intermediate wheatgrass (to the right).

After seeing the vast difference in root systems between annual and perennial plants, does it not make sense that planting a perennial can accomplish far more soil improvement than annual cover crops in the same time frame? There is probably little doubt that this is true, but there is a great hesitancy to plant cropland back to perennials, even among those who greatly desire soil improvement. Why is this so? Listed below are some of the likely reasons for this hesitancy:

  1. The idea that perennials are not a profitable use of cropland.  Most derive this notion by comparing the profitability of acres currently in native grasses to acres growing crops.  It needs to be pointed out that this is usually comparing crops grown on good soil to native grass on poor soil. Remember, the only acres still in native grass are the acres that were too poor to plow years ago.  Additionally, this is comparing the profitability of (usually) well-managed crops to (usually) poorly managed native grass. How often does native grass receive any fertility input? How much native grass is in a constant state of abusive grazing? Put native grass and corn side by side on the rocky, shallow soil where native grass still exists, give neither of them fertilizer, and see which one is more profitable. Can well managed perennial forage be just as profitable as crops on good soil? Experience indicates that it can be, particularly if the value of increased future crop yields is taken into account.
  2. The idea that it takes several years to establish a good sod, especially a warm-season grass sod.  This notion comes from our experience with Conservation Reserve Program plantings, which often took three years before a good stand was established. We have now come to realize that most perennial plants, warm-season grasses in particular, are highly dependent on mycorrhizal fungi for establishment and optimum production.  Even the notoriously slow-to-start native warm season grasses like big bluestem can form a good, thick stand in one growing season with mycorrhizal inoculation.

There has been very little research on sod-based rotations in the US since World War II. After the advent of cheap nitrogen fertilizer in the 1950’s, it was thought that sod-based rotations were unnecessary to maintain crop yields.  Besides, research on sod-based rotations takes longer than the average tenure of a graduate student, does not fit easily into replicated small plot research if it involves grazing livestock, and does not receive funding from any large agribusinesses.  However, there has been one recent study, conducted in Florida, which compared various cotton and peanut rotations with a rotation of one year peanut, one year cotton, and two years of bahiagrass pasture. Here are the results of that study, measured in terms of peanut yields.

Rotation

Peanut Yields

Continuous peanut, no fungicide 1600 lbs/a
Continuous peanut, with fungicide 3800 lbs/a
Continuous peanut, with fungicides and nematicide 4900 lbs/a
Peanut, cotton, cotton rotation 7000 lbs/a
Peanut, cotton, bahiagrass rotation (2 years) 8000 lbs/a

More important was the economic comparison of the rotations. The sod based rotation was from 4 to 27 times as profitable as the others, not only because of higher yields but also because fungicides and nematicides were unnecessary. Nematode pressure was reduced over 90% by including the bahia sod. The income from the pasture more than made up for the loss o fcrop income during those two years. Add all of this up, and (according to their estimates) a family could make a living on 250 acres, where the crop-only rotations required thousands of acres to make a living. Please note, these results were derived from a MONOCULTURE GRASS pasture.  How much better could the results have been if a perennial legume had been included in the pasture, so that the following crop benefitted from nitrogen? What is a deep-rooted forb had been included, to break up the ever-present hard pan? How much better would the animal performance had been with more plant diversity?

Results like these make it remarkable that we have not used sod-based rotations more often.  Sod-based rotations offer the following advantages:

  1. Dramatically improved organic matter and soil structure
  2. Increase in earthworms
  3. Increase in mycorrhizal fungi and possible spore production
  4. Buildup of nitrogen fertility from fixation by legumes and possibly free-living nitrogen fixers
  5. Transfer of mineral nutrients from unavailable forms into available ones through biological processes
  6. Conservation of fertility through return of manure and urine during grazing
  7. Reduction in problems from plant-attacking insects, diseases and nematodes
  8. Annual weed pressure diminishes, particularly if management intensive grazing is used.

Species to consider for sod-based rotations

Eastern gammagrass is probably the top choice, despite its reputation as a slow starter.  Gamagrass has a superior root system to other native grasses, and is simply more productive than any other adapted grass. It also is very shade tolerant, making it possible to establish it as a companion planting with a short season corn or corn silage and cash flow the establishment year. It has a high level of seed dormancy that needs to be broken, either by cold treatment or by a patented treatment called Germtech II.  Planting in midwinter is an effective means of breaking dormancy.  Gamagrass requires inoculation with mycorrhizal fungi for rapid establishment.  Gamagrass is compatible with many legumes, including alfalfa.  Gamagrass requires very careful grazing management in order to be productive.

Native tallgrasses (big bluestem, Indiangrass, switchgrass, little bluestem, sideoats grama) also have a reputation as being slow to establish, but establishment can be greatly enhanced by inoculation with mycorrhizal fungi, with some trials demonstrating as much as a 100 fold increase in first year growth.  Only a few legumes are compatible with native grasses. Native grasses are very drought tolerant and fertilizer efficient, and capable of performing on soil too poor for most other species. This ability to do well on poor soils has been a reason they are often assumed to be nonproductive, because the impression most people have of these grasses is from their production on acres of land too poor to grow anything else.  Given good soil, good fertility, and (most importantly) good management, these grasses are quite productive. Though they can tolerate just about any climatic extreme, they are not tolerant of close continuous grazing, and should be grazed no lower than six inches during the growing season for best results.

Reed canarygrass has a far superior root system to other cool-season grasses, having three to four times the root mass per acre of smooth brome and forming a dense sod. Only low alkaloid varieties should be planted, as wild strains have very poor palatability due to the presence of bitter alkaloids.  Reed canarygrass is slow to establish, and it is often recommended to establish it in alternate rows with a more rapid establishing species like orchardgrass or alfalfa. Planting with tannin containing species like birdsfoot trefoil, sainfoin, and chicory greatly aid animal performance, as the tannins neutralize alkaloids.  Many legumes are compatible with reed canarygrass, though it is a highly competitive grass once established and often eventually forms a monoculture.

Tall fescue is a cool-season grass that has the ability to grow on very poor eroded clay subsoils where other forage species struggle, and forms a dense sod. It also maintains good forage quality in the dead of winter when little else provides quality grazing. Only endophyte free or non-toxic endophyte varieties should be planted.  It is compatible with many legumes and is most often associated with red clover, ladino clover, and Korean lespedeza.

Alfalfa is hands down the most productive legume choice. It has deeper roots, more root mass, more tonnage, and more nitrogen fixation per acre than any other legume adapted to the central US.  However, it can cause bloat and is intolerant of continuous grazing. When combined with other species and rotational grazing, alfalfa can produce more beef per acre than almost any other plant adapted to most of the US.  It is best used in combination with grasses and with tannin containing species, which help control bloat.

Red clover is usually considered the second most productive pasture legume after alfalfa, is much less likely to cause bloat, and is easy to establish by broadcasting. Individual plants only live two or three years so it is necessary to occasionally reseed or manage for long rest periods that allow natural reseeding if it is desired to keep a stand more than three years.

Birdsfoot trefoil is a legume that is only about half as productive as alfalfa but contains tannin that prevents bloat, neutralizes alkaloids, and reduces internal parasites. It is more tolerant of wet soils and acid soils than alfalfa.

Chicory is a forb, rather than a legume, so it does not fix nitrogen.  It is very productive, has very deep roots which impart drought tolerance, grows well in compacted soils, has a very high mineral content, is very palatable and digestible, and contains enough tannin to reduce internal parasites. It is best used in combination with legumes and grasses. Chicory roots are capable of penetrating very dense hardpans. 

Plantain is a low growing forb that has some unusual properties, making it very worthwhile to include in pasture seedings. It contains very effective natural antibiotics, which not only reduces disease and infection but also has an effect similar to monensin (Rumensin) in improving feed efficiency by reducing rumen populations of methane-producing microbes.  Like chicory, it is also very high in mineral content and even more capable of penetrating hard, compacted soil layers. Plantain and chicory have been the rock stars in our perennial forage plots at Bladen.

Ladino clover is a low-growing legume that is excellent quality but not very productive in dry weather or drought. Much of its value comes from its ability to spread by stolons (runners) and fill in gaps between other plants. It is very tolerant of grazing and often becomes a dominant species in overgrazed pastures.

Aberlasting hybrid clover is a cross between easy-to-establish (but drought susceptible and unproductive) white clover, and the slow-to-establish (but deep rooted and productive) Caucasian (a.k.a. kura) clover. Initial reports of this new hybrid indicate that it is definitely worth inclusion in a pasture mix.

Orchardgrass is very productive and quick to establish, as well as being compatible with almost any legume or forb.  New varieties are much more drought tolerant than older ones.

Festulolium is a hybrid of ryegrass and meadow fescue. It combines the high quality of ryegrass with the toughness of fescue. It establishes very rapidly, making it an excellent choice for short-term sods. It tends to be very short-lived, usually persisting only two to three years. It is often included in long term pasture mixes with slower establishing species to gain more early production.

Prairie bromegrass (often referred to as Matua, after the most popular variety of this species) is a very rapid establishing grass similar in use to festulolium. It is rather unique in that plants retain palatability and nutritional value after heading, in contrast to most grasses. It is drought tolerant, but short-lived. If allowed to occasionally produce seed, stands can be maintained for a period of time after the original plants die.

Many other species are being explored for their utility in short-term sod-based rotations. It should be obvious from the descriptions that no single plant is ideal for a sod-based rotation by itself.  Therefore, the best approach is usually to plant a diverse blend with many species, but focused on the more productive species like eastern gamagrass for maximum benefit.

Back to top ↑

Forbs: the forgotten third component of pastures

By Dale Strickler

In the 1950’s, the introduction of the herbicide 2,4-D ushered in a new era of pasture management, in which we were able to selectively eliminate “weeds” in pastures and create nearly pure stands of grass. We initially thought this was a great situation, but soon found out that a pure grass stand was not nearly as productive as a pasture with mixed, diverse vegetation. We first attempted to improve the productivity of these pastures with nitrogen fertilizer, which was generally successful in increasing production, but found that animal performance was not as good as on a mixed pasture, and that these pastures were susceptible to drought. The next attempt to restore pasture productivity was to interseed legumes as a nitrogen source and for improved pasture nutrition. Both pasture productivity and animal performance were improved by this practice, but the more productive legumes like alfalfa also carried a bloat risk. Another drawback of a legume-grass mixture is that controlling broadleaf weeds with broadcast herbicide is no longer an option. It seemed for a long time that there just seemed to be no good answer to restoring pasture productivity, the choices were to either fork over the money for fertilizer and herbicides, or interseed legumes and live with bloat risk and weeds. However, for more than a century there has been a small group of pasture enthusiasts who have been advocating the inclusion in pasture seedings of a little used class of pasture plants: forbs, or herbs as others call them.

Ecologists regard weeds as a sign that there is an unfilled niche; in other words, they are an indicator that there is sunlight, moisture, or soil resources that are not being exploited by what we have planted. If we do not plant something to use those resources, God will plant something that will use them. The only difference between a weed and a forb is that if livestock eat it, we call it a forb, and if they don’t we call it a weed. If weeds thrive in a pasture situation it is a good sign that some forb will also be successful, as long as proper grazing management is applied. As long ago as the 19th century, agriculture writers in Britain were extolling the virtues of including forbs in pasture mixes. More current research indicates that this inclusion was indeed wise. Selected forbs are much higher in mineral content than either grasses or legumes, and many contain chemical compounds that boost animal performance, including some that help prevent legume bloat. In addition, if forbs are included in a pasture seeding, they fill the niche that would otherwise be occupied by weeds, and therefore prevent weed encroachment.

Some of the more valuable pasture forbs include:

Chicory is a forb that has gained quite a foothold in pasture circles. It has a much higher mineral content than either grasses or legumes, and contains compounds that both reduce bloat and reduce intestinal parasitic nematodes. It has very deep tap roots and seems impervious to soil compaction. Livestock ordinarily find it very palatable and the foliage is highly digestible and high in protein, until the plant bolts (forms a flowering stem) when it becomes far less desirable. It is one of the highest yielding pasture species available, comparable to alfalfa in yield if there is sufficient fertility.

Plantain is a low growing forb that may be even more indifferent to compaction than chicory. It is gaining popularity rapidly and the reviews we receive are very positive. It is also palatable and nutritious, has a high mineral content, and regrows rapidly after grazing. It contains strong antimicrobial compounds which help animals fight off infectious diseases, and function in the rumen similar to ionophores like rumensin and bovatec, increasing animal feed efficiency.

Burnet is one of the most drought tolerant forbs, and is unusual among plants in that it retains its nutritive value at all seasons and growth stages, even in winter. This is a valuable characteristic to livestock, but also to wildlife. There are stories of deer pawing through deep snow to eat still-green burnet plants in midwinter.

These plants are also some of the absolute best plants available for breaking compaction, and often the best compaction remedy involves the seeding of a forb-rich temporary pasture, inoculating the seed with mycorrhizal fungi, and grazing it for a year or two. The action of the forb roots, the grass roots, the mycorrhizal hyphae, and animals such as dung beetles and earthworms act to penetrate and loosen the tightest, heaviest plowpan.

In summary, including a few forbs in a pasture seeding can make the pasture more productive, more nutritious, and the animals grazing it healthier. They can also have a great benefit upon the soil itself, deepening the root zone and alleviating compaction.

Back to top ↑

Have you subscribed to our newsletter yet?