Retaining white clover in multi-species pastures – a review

By Patrick Francis

In perennial pasture growing districts like central Victoria (Moffitts Farm) a significant percentage of clover species in a multi-species pasture will contribute to lower sheep and cattle methane emission per kilogram of live weight, to the tune of 5 – 20% lower emissions, while at the same time providing higher quality fodder and adding nitrogen to the soil.

The problem is white and red clovers and sub clovers can be difficult to retain in a significant proportion above 30% of pasture dry matter mass if they have to compete with a mix of desired grass species like ryegrass, cockfoot, tall fescue and Phalaris and the undesirables species like Yorkshire Fog, Sweet Vernal and Silver grass.

Such a high clover proportion can mean a lower total herbage mass grown per hectare per year compared with high proportion grass species pastures, but there is a trade-off between kilograms of dry matter per hectare, faster growth rates and lower methane emissions per kg of liveweight when comparing clovers and grasses.

These outcomes have been our experience since embarking on sowing a higher percentage perennial clovers in multi-grass species pastures since 2015. Our mix has included three perennial clovers, three sub clovers and six grass species including summer active and summer dormant varieties of cocksfoot and tall fescue.

The scenario has been an acceptable strike of all species in year one, then a gradual decline of clover species by year three with the grasses becoming 90% of the sward.

The same scenario was happening with chicory planted with the perennial clovers and grasses in the multi-species mix (10 species). It generally survived two years before loosing out to grass competition. A different approach to species mixes was needed for:

* paddocks where high clover, high chicory content provided the right quality fodder on which to finish lambs and to carry lactating ewes while reducing methane emission per kg live weight, VERSUS

* paddocks for dry ewes, and replacement ewe weaners where high levels of grass dry matter production is required to return ewes to optimum conditions scores and slowly grow the replacement weaners.

Research into how high clover (chicory) content pastures can be maintain is clear but implementation for profitable livestock farming while retaining species persistence, improving soil health and water holding capacity, and avoiding nutrient leaching while reducing methane emissions is complicated. At high (>18dse/ha/yr) and moderate paddock (10dse/ha/yr)  carrying capacities management for high clover content is likely to evolve trade off between these issues. At low paddock carrying capacities (less than 8dse/ha/yr) in the medium to high rainfall district retaining a higher clover content pasture is extremely difficult as competition from grasses without having sufficient livestock grazing pressure will mean grass dominate pastures unless mechanical interventions are applied.

Research into how perennial clovers such as white and red clovers can be retained in moderate to high proportions in association with grasses has been undertaken most often in EU countries, USA, and New Zealand. Research in Australia is limited as suitable moderate to high rainfall districts are relatively small in area compared to lower rainfall districts where research concentrated on persistence of sub clovers in perennial pastures and in pasture leys for cropping rotations.

Juan Soloman Mississippi State University in his research thesis undertook a literature review to identify and agronomy and persistence the issues associated with legume/grass pasture mixes. “Grass-legume swards have been considered by farmers difficult to establish satisfactorily and difficult to manage so as to ensure a sufficient legume component, especially under grazing.”

He identified contributing difficulties:

• Forage species differ in resources they require to grow, develop and reproduce and this explains one of the problems with growing grasses and legumes in mixtures. If each species requires a completely different set of resources from every other species, the only “resource” they would compete for would be physical space.
• Once white clover has become established, vegetative reproduction occurs through stolon development and this mechanism is responsible for resistance against mechanical stress resulting from grazing livestock. As a perennial species, its vegetative reproduction is supported by self-regeneration from season to season but crucially, it exhibits low competitive ability against grasses. Thus, long-term investigations of grass clover mixtures have shown that the survival of white clover depends mainly on the competitiveness of associated grasses.

Figure: If the grasses in a multi-species pasture are too competitive in winter the clovers will struggle to access sufficient sunlight. Photo May 2026

• The extent to which grass-clover relationship is influenced by temperature and nitrogen (N) is strongly dependent on the stage of development of the canopy. Canopy development effects comprised of three stages with variable duration: 1) active increase in light capture, 2) light capture and, 3) maturation. The species with the highest rate of leaf area expansion will increase its share of the light intercepted at the expense of its competitor. This tends to be a general problem in binary mixtures of ryegrass-clover swards thus clover suppression is inevitable.
• In the absence of defoliation, differing height responses of grass and clover to winter temperatures can result in clover suffering severe competition for light. Since more grass leaf than clover leaf is present in the upper layers of the sward in the spring, it is not surprising to find that spring defoliation can be beneficial in terms of clover composition. The timing of the first harvest cut or grazing is also crucial for determining the competitiveness of white clover and sustaining it. White clover colonizes areas of damaged swards caused by heavy grazing and trampling of animals as well as herbicide damage.
• The vertical and horizontal structure of a perennial ryegrass and white clover sward influences grazing. In mixed patches of a strip sward, clover was also more defoliated than ryegrass (30.0 vs. 18.0%). For continuously stocked ryegrass-clover mixtures, differential defoliation of species varies according to vertical distribution of leaves but is little affected by horizontal structure of canopy. When grazed by sheep, which have a high capacity of selective grazing, the degree of mixing between ryegrass and clover has little effect on the pattern of species defoliation. The reasons suggested for this trend was that sheep were able discriminate not only among patches with or without white clover but also for clover within small patches where the two species are present.

Figure: a challenge for grazing management with white clover is flowers and subsequent seeding can be significantly reduced if grazed at peak flowering. Photo December 2025

• Three ways in which grazing animals may affect the relationship between grass and clover; 1) grazing intensity (such that the remaining herbage includes more of one species than others), 2) deposition of dung and urine resulting in: (a) uneven pattern of N distribution in the soils and (b) subsequent avoidance of recently contaminated areas, and by (3) actively selecting clover rich areas. Stocking rates influences clover-grass sward because it determines grazing intensity. At a high stocking density, clover composition of pastures generally decline due to intense selection of clover by grazing animals. Increasing the stocking from 25 to 55 yearling sheep per ha reduced herbage accumulation by 40%, whether or not N fertilizer was applied. The increased stocking rate increased the density of ryegrass tillers, but reduced the density of clover stolons and the clover composition of the sward. Uneven deposition of dung (faeces) and urine by grazing animals can influence the cover of grass-white clover swards dynamics in mixed pastures. In a study of white clover under grazing conditions, the return of urine reduces stolon population density and N2 fixation of white clover by indirectly stimulating grass growth. An additional effect of faeces return on grazed grass-clover pastures is the rejection of herbage around dung pats resulting in changes in grass and clover morphology. In general, both sheep and cattle show active selection for clover in mixed swards even in swards where clover proportion is low, thus disadvantageous for clover existence in mixed pastures.
• It is generally true that measures, which promote the growth and competitive ability of grasses, particularly the application of N fertilizers, reduce white clover in the sward. The application of 200 kg N/ha annually increased herbage accumulation by 20% but substantially reduced the clover content. If white clover is desired in the sward, then the amount of N fertilizer has to be reduced with consequences for grazing management.
• When clovers are sown with multi-species grasses another issue develops – the stage of maturity vary among different grass species, often by up to two months. The timing of ear emergence is also highly variable amongst different grass or legume species and between cultivars within a species. With increasing stage of maturity the proportion of cell wall components of the grass (cellulose, hemicellulose and lignin) increases, whereas the proportion of cell contents decreases. Because of the changes in cell wall content and the stem:leaf ratio with increasing maturity, the digestibility of grasses is highest in the vegetative stage.(Bruinenberg et al)
• In general, the intake of legumes is higher than that of grasses, which can be attributed to higher crude protein concentration, lower cell wall content, faster reduction of the particle size in the rumen and faster rate of removal of organic matter from rumen. (Bruinenberg et al)
• Stems can have a barrier in livestock bit size and instantaneous intake rate. The higher the stem density, the smaller the area and the slower the biting rate. Stem length and stem proportion in the sward have a negative impact on biting rate. (Virginie Decruyenaere et al)
• Sward composition, in terms of plant species can also influence the level of intake. Compared to grasses legumes such as white clover are often associated with higher intake levels. Legumes are faster reduced into small particles than grasses and less time is needed to take and masticate a similar bite for clover than for grass. (Virginie Decruyenaere et al)

Figure: In multi-species white clover – grass pastures the grasses will flower at a range of different dates, (in central Victoria starting in mid September with sweet vernal grass,  late September with Yorkshire Fog grass through to late October for phalaris and November for late season ryegrass varieties) and can make it more difficult for sheep to efficiently graze the legumes between the stems. If sufficient stocking rate cannot prevent the grasses flowering then mechanical topping not only provides easier access to the legumes but can also encourage summer active grass species to tiller and grow more palatable leaves. Photo 2 December 2025.

Clover growth and persistence

• The climatic factor temperature has a critical effect on clover growth because in the field clover grows most rapidly during spring and autumn, when moderate temperatures prevail. Total plant dry weight for white clover was greatest at 16.7 and 23.3°C and was reduced at both 10 and 30°C. The ability of white clover to survive high temperature is very dependent on soil moisture levels and clover survival is reduced as temperature increases.
• The major constraint to white clover persistence is mainly moisture stress and this has been a continuing problem in some areas worldwide.
• Survival of white clover in swards at establishment is critically dependent on phosphorus (P) supply, and that one of the main benefits of liming is the resultant improvement in P availability. Increased P nutrition for white clover improved soil-plant water relations through an increase in coarse and fine roots and an overall increase in root length density. The resulting effects of this trend is greater extraction of soil water from drying soil, enhancing white clover ability to persist in water deficit areas.

Figure: Phosphorus is a critical element for optimising clover growth. P plant availability is associated with soil pH above 5 (in CaCl2). Photo April 2026.

• Increased drought tolerance of frequently defoliated high P white clover plants was apparently related to their greater root growth, particularly coarseness, length, density, and increased xylem diameter in the primary roots. Consequently, an increased root conductivity of these plants enhances the water uptake and leaf area expansion, even under dry conditions, compared with low P plants.
• Use of mineral N on white clover swards have all generally showed negative consequences unlike its use on grass swards. Several studies have shown that mineral N application on clover swards has a negative impact on the N2 fixing capabilities of white clover.
• Prolonged application of N fertilizer reduces infections and resultant nodule formation by Rhizobia in the soil as well as restricting nodule development. The presence of readily available soil N favours uptake of mineral N by clover since this is an energetically less expensive process than fixing atmospheric N, thus clover substituted fixed N for mineral N. High soil N levels can lead to reduce persistence of white clover in pasture systems.
• In undisturbed white clover, the prevailing light and temperature conditions control the number and size of leaves, size of stolons and their rate of development in pure clover and mixed swards. The most marked response of white clover to reduced light intensity is a reduction in the formation of stolons from axillary buds. Stolon growth is important in the production and persistence of white clover. The key to persistence is a high growing density, but this varies with season.

Grazing management

• Regardless of cultivar leaf size classification, permitting seedlings to develop at least four trifoliate leaves before initial defoliation will provide the greatest opportunity for seedling growth and potential survival. Under rotational stocking with sheep, white clover can give reliably high yield over a 10 year period.
• White clover could withstand frequent defoliation during the spring and early summer and less frequent defoliation during late summer and autumn without stolon loss associated with season long frequent defoliation.
• Voluntary intake of legume forage is 10-15% greater than that of grasses owing to the lower resistance of legumes to chewing, a faster rate of digestion and particle breakdown and clearance from the rumen, which in turn reduce rumen fill. Rate of decline in nutritive value for white clover throughout the plant-ageing process is much lower than for grasses. (Kumar et al)
• Maintaining high proportions (40 – 60%) of white clover in a grass + legume pasture is key to maintaining herbage production from year to year but this can be difficult under grazing conditions.
• Grazing livestock consistently show a partial preference for a diet that consists of approximately 70% legume and this places a selective pressure on the legume as opposed to the grass in a mixed sward. The grass-legume competitive interaction is also influenced by soil N. As animal excreta increases soil N under grazing, the legume proportion of the sward becomes less competitive.

Nitrogen fixation

A key asset of white clover in pastoral systems is their ability to convert atmospheric N into N available for plant use, table 1.

Table 1: The wide variation in N2 fixation by clover pastures is caused by varying clover percentages in the measured pastures.

High intensity grazing, especially frequent defoliation during spring, of white clover sward produces annual increases of 10 to 33% in biological N fixation.

• Voluntary intake of legume forage is 10-15% greater than that of grasses owing to the lower resistance of legumes to chewing, a faster rate of digestion and particle breakdown and clearance from the rumen, which in turn reduce rumen fill. Rate of decline in nutritive value for white clover throughout the plant-ageing process is much lower than for grasses. (Kumar et al)
• Maintaining high proportions (40 – 60%) of white clover in a grass + legume pasture is key to maintaining herbage production from year to year but this can be difficult under grazing conditions.
• Grazing livestock consistently show a partial preference for a diet that consists of approximately 70% legume and this places a selective pressure on the legume as opposed to the grass in a mixed sward. The grass-legume competitive interaction is also influenced by soil N. As animal excreta increases soil N under grazing, the legume proportion of the sward becomes less competitive.

For a given production system, management, soil and climate, the magnitude of N losses to water from agricultural systems primarily depends on the overall input of N, rather than whether the initial source of that N is fertilizer N or atmospherically fixed N. For example, nitrate leaching from pasture based dairy systems increased exponentially with increased N input regardless of whether it was from fertilizer N or biologically fixed N.

Nitrogenase activity is reduced when available soil N increases. Therefore, (unlike fertilizer N applications) N fixation responds directly to the levels of available soil N, increasing N inputs when soil N is low and lowering them when soil N is high. This means that N fixation can function as a self-regulating negative feedback loop which could potentially increase N efficiency and reduce losses, relative to fertilizer N.

In grazed grass + legume swards, N fixation is usually less than 200 kg/ha which limits their ability to leach nitrates and can make them a suitable option for nitrate-vulnerable regions.

Figure 1: Both N input and N-leaching tends to be lower with grass + legume pasture than with grass + fertilizer N pasture.

Animal Feeding Value and Nutrient Composition

• The essential qualities of this important forage crop white clover are its protein and mineral rich constituents, and ability to retain high digestibility since there is continual generation of new leaves from stolons, which is partially compensating for advance in maturity of the existing foliage.
• Another important characteristic of this forage is its high palatability compared to many grass species.
• Low retention time in the rumen owing to low fiber and hence higher voluntary intake at equivalent digestibility.
• Reported nutritive values for white clover in gram per kg dry matter: CP = 266, pure protein = 196.0, crude fibre = 199.0, ash = 85.0, P = 4.9 g, K = 26.0, calcium (Ca) = 9.0, magnesium (Mg) = 2.0 and sodium (Na) = 3.0
• Inclusion of white clover in the diet of cattle leads to greater milk production and increased liveweight gain of grazing cattle and sheep.
• Of the 289 moderate and severe cases of cattle bloat observed during their experiment, 221 occurred on pastures with a high proportion of clover (60 to 80% white clover) compared to 58 on pastures with medium (20 to 50%) and 10 animals on pastures with a low proportion of clover (15 to 25%).
• The presence of high levels of condensed tannins (CT) in white clover aid in the reduction of bloat and protein degradation. White clover flowers contain CT and as the proportion of flowers increased, CT levels increased from 0 to at 100% flowering 52.4gCTper kg DM.
• For forage quality improvement, white clover should not be below 30% in the mixture.
• When proportion of white clover in a mixture with tall fescue was between 20 to 40%, improvement in animal gains was found.
• The combination of grasses and legumes for animal feed is very important in the sense there is complementarity in the mineral composition of the two species. P is one of the key mineral elements for plant development and animal growth and also critically contributing to conserving and conveying of energy in animal and plant metabolism. P is an element of significant molecules including ATP, nucleic acids and phospholipids in plants and animals. (Esan V. et al 2023)

Methane output

• In general, forage legumes have been found to result in lower CH4 emissions per kg of DM intake or per kg meat production when compared to grasses. However this generally only occurs where the legume has higher feed intake and ruminal passage rates than the grasses it is compared to, or with legumes that contain condensed tannins. For example, a comparison of CH4 emissions (per kg DM intake) from sheep fed fresh perennial ryegrass and white clover, found the while clover resulted in 12% lower emissions in autumn/winter but resulted in a 7% higher emissions in spring. (Phelan et al)
• Forage legumes with CT in their herbage can reduce CH4 production from ruminants in comparison to other forages. A 13 – 16% reduction in CH4 per kg DM intake has been found. (Phelan et al)
• Forage legumes are also associated with lower direct CO2 emissions than forages that are more reliant on fertilizer N. This is because the production of fertilizer N is an energy-intensive process using approximately 60 MJ of energy to produce 1 kg of fertilizer N and this energy is currently provided by large amounts of fossil fuel consumption, particularly natural gas. Large amounts of CO2, are associated with the production and transport of fertilizer N, at rates of approximately 3.5 to 4.0 kg of CO2 released for every kg of fertilizer N. (Phelan et al)

Australian ruminant scientist Dr Richard Eckard and consultant Stephen Wiedemann are advocates for increasing legume content in pastures as one strategy farmers can use to reduce livestock methane emissions, figures 2A and 2b. However, detail about legume percentage within the pasture dry matter is required to achieve specific methane reduction targets. As well the best option legumes to use needs identification in southern Australia’s over 600mm grazing districts where cropping is not part of management.

Figure 2A:  Legumes based pastures are promoted by Richard Eckard for reducing methane emissions but what percentage of the total dry matter pasture mix to be effective is yet to be determined.

Figure 2B: Consultant Steve Wiedemann indicated in 2022 that legumes can help reduce livestock methane emissions by 5 – 20%

In a MLA  November 2025 review of anti-methanogenic pastures and forages written by Ed Charmley, white clovers and chicory were not included as part of the southern Australia species comparison, only lucerne, brassicas and plantain. Chamley concluded “that the opportunity for plant species to reduce methane from grazing livestock was modest due to the generally low reductions in methane these species elicit, and the small contribution they make to the animal’s diet. Nevertheless, when adopted across large numbers of livestock they can make a useful contribution towards reducing methane emissions from the grazing sector. Many of the most promising species with anti-methanogenic properties were forecast to improve the nutritive value of pasture, thus increasing reproductive efficiency and animal weight gain leading to changed herd/flock structure, earlier animal turnoff, and increased carrying capacity. Consequently, predicted reductions in methane production per unit of feed intake were often offset by increases in total methane emissions. In summary, the intensity of emissions per unit of animal product is likely to be reduced while total emissions per area may increase. The lack of scientific information on methane dynamics under commercial field conditions hampers the development of a methane avoidance method and further research is required.”

Apart from co-benefits of lower methane emissions associated with some pasture species the direct avoided emissions have a possibility to producing financial benefits. On this point Charmley concludes the avoided emissions “may be voluntary, whereby a producer can sell, offset, or inset carbon credits earned into the voluntary market, or government sanctioned schemes, such as in the Australian Carbon Credit Unit (ACCU) scheme. The bar for entry into the latter is much higher than for the former, and likely prohibitive in the case of a pastures method.”

Biodiversity value (Phelan et al)

The greatest effect that forage legumes have on biodiversity is to increase the diversity and abundance of pollinating insects, particularly bees, when compared to grasses or cereals. This is because forage legumes are generally insect pollinated, whereas their non-legume counterparts (grasses, cereals and maize) are wind pollinated.

Figure: White and red clover varieties are an important food sources for pollinating insects.

Greater earthworm abundance and diversity has been recorded under legumes than under other plants groups such as grasses, due to the higher soil organic matter and N contents, and the lower C:N ratio of legume litter.

The effect of incorporating legumes into agricultural grassland on earthworm and other soil macro-invertebrate biodiversity is expected to be lower if it coincides with a reduction in fertilizer N input. Earthworm abundance (but not diversity) increased with increasing N input (fertilizer and stocking rate) in grazed grassland and there was no difference in earthworm abundance between a grass-only sward receiving 150 kg fertilizer N/ha and a N unfertilized grass + White clover sward (20-30% clover in herbage DM.

Take home message (Phelan et al)

The potential of multi-species grass-legume mixtures to maximize resource/input use (land, fertilizer, water), with associated benefits for both farm profit and environmental quality, appears to be of renewed interest in recent years.

References:

Juan Solomon, ‘A novel approach to grass-legume management’,  A Thesis Submitted to the Faculty of Mississippi State University 2010

P Phelan et al, ‘Forage Legumes for Grazing and Conserving in Ruminant Production Systems’ Critical Reviews in Plant Sciences, 34:1-3, 281-326, 2014

Kumar et al ‘Multiple agroecosystem services of forage legumes towards agriculture sustainability: An overview’, Indian Journal of Agricultural Sciences 90 (8): 1367–77, August 2020

V Esan et al ‘Growth and nutritional potential of selected grasses and legumes from ruminants production; Earth and Environmental Science 1219 ( 2023) 012011

Ed Charmley “A Review of anti-methanogenic pastures and forages” Final Report, MLA Project code: B.PAS.0012, 25th November 2025

M. H. Bruinenberg et al ’Factors affecting digestibility of temperate forages from seminatural grasslands: a review’, Wageningen University, The Netherlands, Grass and Forage Science, 57, 292–301, 2002.

Virginie Decruyenaere et al , ‘Factors affecting intake by grazing ruminants and related quantification methods: a review’, Biotechnol. Agron. Soc. Environ. 2009 13(4), 559-573