Plantain is a herb with a fibrous and coarse root system that grows throughout New Zealand. It has high tolerance to summer heat and in warmer regions can provide valuable summer growth. Plantain is best suited to dairy farm situations where the amount and quality of summer feed limits milk production.
There are two ways to grow plantain: as a pasture mix or as a special purpose crop. Plantain will last 2-3 years under dairy grazing.
Frequently asked questions
What is Tonic plantain?
The well-known weed plant plantain was developed into vigorous and upright-growing cultivars. ‘Tonic’ is one of the modern perennial plantain cultivars, it is very different from the common weed types found in pasture, with larger leaves, an erect growth habit and greater winter activity. We specifically refer to ‘Tonic’ because current research is based on sowing this cultivar. There are other plantain cultivars on the market however they may require different management. Talk to your local seed representatives for cultivar options.
How long will plantain last?
Plantain will remain productive for 2-3 years. Plant numbers will decline over this time with the rate of declined depending largely on weed control, nitrogen fertiliser application, and grazing management.
The key management principles for longevity and yield of a special-purpose crop include: managing overgrazing and treading damage, frequent grazing at 25cm height, residual height, and first grazed no earlier than the six-leaf stage.
What do you mean by special-purpose crop?
Grown as a single species (or with clover) and managed as crop. Alternatively, plantain can be sown in a mixture with grasses, legumes, and other herbs. Commonly, 1-4kg/ha of plantain seed is added to a ryegrass mix, and managed as a normal grass and clover pasture.
Can plantain be used for reducing nitrate leaching?
Research is in progress but plantain-based pastures may be useful for reducing nitrate leaching while maintaining or increasing milksolids production.
The urine patch is the major source of nitrogen loss to the environment on dairy farms and different forages can be used to reduce nitrate leaching, either by lowering the nitrogen loading in urine patches or increasing the nitrogen uptake from the urine patch.
Forages for Reduced Nitrate Leaching (FRNL)
Research in Canterbury and Waikato the FRNL programme has found that urine-N concentration of cows grazing plantain was 56% lower than those grazing perennial ryegrass/white clover pastures, and 33% lower for cows grazing 50/50 pasture-plantain.
Within FRNL, diverse pastures that include plantain were identified as a promising tool for reducing N leaching. Modelling estimated that, at commercial scale, N leaching could be reduced by 10 and 20% when the area of the farm sown in diverse pastures was 20 and 50%, respectively. This was because of lower total urinary N excretion and lower urinary N concentration (Beukes et al. 2014; Romera et al. 2016).
Plantain produces 10-19 t DM/ha/year. The average yield from spring sowing to May (specialist crop with or without clover) is 11 tonnes/ha.
Despite the moderate drought tolerance, plantain still requires moisture to grow well, and under severe drought yield will be reduced. Under these conditions plants will wilt; however, they recover quickly following rain or application of irrigation or effluent.
Growth rates of Tonic plantain between spring and autumn range between 25 and 80kg DM/ha/day, potentially peaking at 140kg DM/ha/day in summer. Growth rates during winter are lower (15-35kg DM/ha/day).
Quality and milk response
Well-managed plantain (0-25% stem) generally has a lower dry matter content than ryegrass pasture and contains less fibre.
The metabolisable energy (ME) content is similar. Yet, plantain may be better quality than ryegrass during hot, dry summers. Therefore, milksolids response to plantain appears to depend on the quality of the pasture diet: if pasture quality consistently drops away in summer, then including plantain can increase per cow milksolid production.
Management and feeding
When plantain is in a pasture mix, the paddock should be managed as a normal grass and clover pasture. This means grazing to residuals of 1500-1600kg DM/ha. When plantain is sown as a special purpose crop it requires different management. The key management activities to maximise yield, quality, and persistence are outlined below:
When to start grazing?
Plantain crops should be first grazed no earlier than the 6-leaf stage (i.e. the plants have six fully grown leaves). This is normally 7-8 weeks after spring sowing. This ensures plants have well-developed root systems to improve survival.
How much to feed?
Aim to feed about 20% of the cows’ daily diet (3-4kg DM/cow) in plantain over a sustained period as the rumen requires time to adjust to plantain - like any fed type change. To do this, 5-6ha of plantain should have been planted per 100 cows.
What are the target covers for best performance?
Target cover heights are measured by leaf height ignoring the stems.
- Pre-grazing height is 25cm (generally this is 4-6 weeks of regrowth).
- Post-grazing height should be 5cm.
Letting the leaves grow beyond 25cm will not accumulate any more leaf, just increase growth of the lower-quality stem. Dairy cows will readily graze lower than 5cm and management strategies need to be in place to ensure this does not occur. Grazing should be avoided when soils are wet as treading damage has a major impact on plant survival.
Approximate time to reach 25cm based on data from Waikato*
* These times may change depending on temperature and soil moisture in your region, i.e. slower growth when temperatures are cool or if there is low soil moisture
How can I use the 25cm height to allocate the right area?
As a rough guide, a dense (approximately 180 plants/m2) first-year pure plantain crop at DairyNZ had a pre-grazing mass of 3300kg DM/ha at 25cm height.
In comparison, a less dense crop (approximately 80 plants/m2) had a pre-grazing mass of 2300kg DM/ha at 25cm height.
If we assume, on average, that the pre-grazing mass of plantain at 25cm height is 2800kg DM/ha and the post-grazing residual of 5cm will be 1500kg DM/ha, this gives an available grazing of 1300kg DM/ha.
For cows to eat 3-4kg DM per day:
- Allocate area based on 20-30m2/cow
- Monitor cow grazing - optimum grazing reaches 5cm residual height after about 3 hours
- If cows reach 5cm in less than 3 hours, increase allocated area
- If after 3 hours the grazing residual is more than 5cm decrease the allocated area
Using the plate meter is another useful way to estimate plantain crops
Like pasture, the rising plate meter can be used to estimate the yield of plantain crops.
Take at least 40-50 readings in a ‘W’ shape across the paddock and calculate yield using the equation: Yield (kg DM/ha) = RPM height (clicks) x 94 + 455. This equation is affected by many factors so it is important to check post-grazing residuals as explained above to ensure adequate herbage allocation. The dry matter percentage of plantain ranges from 9-20% so yields will vary.
Dairy systems with plantain
Aim to feed 20% of the cows’ daily diet (3-4kg DM/cow) in plantain over a sustained period as the rumen requires time to adjust to plantain.
This requires about 5-6ha of plantain per 100 cows. This is around 0.3 ha per 100 cows each day offered as a 2 to 3-hour break with back-fencing to ensure good regrowth. This system provides for a 21-day grazing rotation, but may need to be adjusted if plantain growth is unusually slow or fast. It provides a daily diet of plantain, which is important as it reduces any rumen adjustment needed if cows are switched from ryegrass to plantain part way through a rotation.
Plantain can be grown as a special-purpose crop or as a pasture mix with grass or clover.
A special-purpose crop is often recommended where suitable soil types and a convenient location are available, as management can be tailored to meet the requirements of plantain; undesirable grasses (e.g. yellow bristle grass) can be removed using grass-specific herbicides.
The recommended seed mix is 8-10kg/ha plantain with or without clover.
A grass/clover/plantain mixed pasture is managed like a normal pasture and plantain can be added to a pasture/clover mix at 1-4kg/ha depending on the content required.
Plantain is more sensitive than ryegrass to sowing depth and soil temperature. It establishes best when sown into warm soils (10-12°C) at no greater than 10mm depth and where there is little competition from other plants in the first three months.
Spring Is preferred as plants develop quickly Early autumn Can result in successful establishment, but plants develop slower, later in autumn is not advised
A Waikato trial indicated the best way to sow plantain is applying herbicide to existing pasture and direct-drill the seed. The increased cost of spraying and direct drilling is more than compensated for by the increased herbage yield. Where cultivation is appropriate, using a roller drill, pre-emergence insecticide, and treated seed.
Plantain should be first grazed no earlier than the six-leaf stage, i.e. the plants have six fully grown leaves, this is normally 7-8 weeks after spring sowing. This ensures plants have well-developed root systems to improve survival.
Plantain can grow on a range of soils, however it performs best when grown on free-draining soils. Plantain growth will be maximised on high-fertility soils which are not prone to waterlogging or treading damage in wet weather.
Soil type: Avoid heavy clay soils and those prone to waterlogging Soil pH: 5.6 to 6.2 Soil fertility: As for ryegrass pastures. Nitrogen fertiliser (e.g. 70kg/ha urea) improves establishment
Annual maintenance phosphate, sulphur and potassium are the same for plantain as for ryegrass pastures. Plantain is very responsive to nitrogen fertiliser even during the summer. At least two to four urea applications of 80kg/ha post-grazing are recommended over the spring/summer.
Weeds should be thoroughly eliminated before sowing as there are few suitable post-establishment herbicides for plantain. Talk to local seed representatives for herbicide recommendations.
Withholding periods for residual hormone herbicides (e.g. clopyralid, MCPA) must be adhered to as plantain is very sensitive to these herbicides.
In late February to mid-March, holes may begin to appear in plantain leaves. These are caused by caterpillars (e.g. common carpet moth, white butterfly, diamondback/cabbage moth). As the caterpillars do not feed on roots or growing points, their impact is largely aesthetic. If damage is severe the caterpillars can be controlled with an approved insecticide. See AgPest for identification and control.
Establishment into existing swards
The best method for establishing plantain into an existing sward is direct drilling, with a maximum plantain content of between 15 and 30% of the pasture DM being achieved.
Direct drilling into low cover (after hard grazing or mowing) and early grazing after sowing while seedlings are small enough to avoid defoliation (approx. 8 clicks on a plate meter or 4 cm) is recommended.
While broadcasting seed is the simplest and cheapest technique of sowing, it reduces the number of plants that establish, reduces the yield and increases the number of weeds in the crop. The increased cost of direct drilling, compared with broadcasting seed (approximately $240/ha), is more than compensated for by the increased yield (2.2 t DM/ha).
Identifying research priorities for establishing plantain on-farm
A modelling exercise was carried out to establish the drivers of cost when establishing plantain to achieve 20, 25 and 30% in pastures on farm. This showed that the most important factors were the percentage of plantain that can be established in an existing sward and the cost of doing so (e.g. broadcast, drill). Secondly, the percentage of plantain establishing in new pastures and the persistency of plantain were also important factors.
For more information refer to Chicory and Plantain – your questions answered.