Growing Fodder Beet

The key to successful fodder beet is to follow good practices, starting with paddock selection. Fodder beet requires attention to detail to get good results.

Fodder beet has commonly been a grazed feed for wintering non-lactating cows in the cooler regions of New Zealand. It is now common for cows in Canterbury and Southland to have fodder beet in their diets for up to six months of the year and it is being fed to all classes of dairy livestock. Fodder beet is now grown in all major dairying regions.

Areas of fodder beet are now lifted and fed on feed pads or in the paddock using a silage wagon. As a crop with a long shelf life, either in the ground or harvested it is a flexible crop with lots of positive attributes but also several animal health risk factors.

Paddock selection

Identify paddocks intended for sowing fodder beet at least 12 months before sowing of the crop.

Wintering on grazed fodder beet on the milking platform potentially reduces the number of cows able to be milked by reducing the effective milking platform area, however, it can be an option to save on winter grazing costs. Consider the economics of your system and goals.

Fodder beet can also be fed early to fill a late lactation feed gap; however, the loss of potential yield should be considered when harvesting fodder beet early. Consider establishment costs and yield compared to other summer feed options. If being used as an early lactation supplement, consideration should be given to the timing and logistics.

Fodder beet is very sensitive to acid soils and the pH needs to be tested (pH of 6 to 6.5 is required) and lime applied at least 6 months before sowing if required. Fine lime can be used closer to planting but this will be more expensive and achieve only a shorter-term increase in soil pH.

If following another crop, ensure that the paddock history is known before planting as seedlings can be susceptible to residual herbicides applied the previous season. For further advice on residual chemical impacts consult your technical field rep or seed supplier.

The area required to feed a certain number of animals depends on crop yields and intended animal intake. On heavier soil types or a high DM yield, care needs to be taken to select paddocks less susceptible to pugging damage and to minimise run-off during grazing.

Consider regional council environmental regulations such as proximity to waterways, potential water run-off, and logistics of feed management issues such as access to stock water.

Soil preparation and pre-sowing considerations

Fodder beet is a specialist crop and must be planned with contractors well in advance.

Fodder beet is sown at a low seeding rate so a weed-free seed bed is for important optimal germination.  Fodder beet is particularly vulnerable to dry conditions and competition from weeds during establishment. A good way to reduce this risk is to use a 'stale' seedbed - where the seedbed is prepared 4-6 weeks before sowing. Only use glyphosate for plant knockdown as other chemicals can have residual effects on subsequent growth.

It is important to bury plant material at least 25cm with a mouldboard plough and ensure that sub-soils are free of pans. Ploughing should be followed by multiple surface workings producing a surface that is as fine and clod free as possible. Apply basal fertiliser prior to the last surface working and roll with a Cambridge roller prior to drilling.

Lifting versus grazing

Plan for how you intend to use the crop. Sowing in 50 cm rows means there is an option to lift as well as graze the crop. Precision sowing using GPS steering will make lifting easier and decrease wastage.

When planning to lift a crop, be aware of the amount of nutrients removed per tonne of yield, especially potassium, and consider the needs of future crops. This can be very useful from an effluent block management point of view as it will help reduce the K content of the soil if the fodder beet is fed elsewhere.

Choosing a fodder beet variety

Select the variety based on desired end-use:

• High DM% variety for lifting
• Intermediate DM% varieties can be grazed or lifted
• Low DM% varieties are only suitable for grazing
• Class of livestock and previous experience with fodder beet
  • Low DM varieties are better suited to young stock and cows who have not experienced fodder beet

Planting layout

How the crop is to be managed should inform the planting layout. For grazing remember to allow for good cow access during transition onto the crop – you need space in the paddock to manage the all-important low allocation of crop per cow.

Planting layout can be used to assist with crop allocation in uniformly shaped paddocks.  Grazing parallel to the rows provides a clear break to minimise the risk of cows eating too far under the wire and increasing their allocation.

A 6-metre-wide (or greater) headland parallel to the rows can be made by planting a green feed crop or by lifting beet for transitioning cows before dry off. If you expect to lift a strip plant a high DM% variety in 50cm rows spacing to make harvesting easier.

Think about how and where supplements will be fed. Look to optimize the number of mobs and laneways required, this will save time and improve supplement utilisation in winter. A map of how you want the paddock planted can help the contractor with their cultivation and sowing decisions.

Sowing

Fodder beet needs a fine, firm, moist seed bed with good soil-seed contact to achieve a uniform plant population.

Precision sowing

A precision planter is recommended for sowing fodder beet as it ensures that seeds are planted with appropriate spacing, enabling each bulb to grow to its potential.

Fodder beet is normally sown at 80,000–90,000 seeds per hectare (8-9 seeds sown per m2) – 50cm row spacing and 25cm between plants in the rows. The optimum sowing depth is around 2cm.

For harvesting types, increase the sowing rate to suit the variety, the drilling environment, the drill spacing, and the type of harvester. This will typically be between 100,000–120,000 seeds per ha.

Rolling the paddock after drilling with a Cambridge roller will help to maximise seed-to-soil contact giving more even germination.

Sowing date

This is location and temperature-dependent, but generally, October to late November is recommended. Soil temperature should be at least 10°C and stable or increasing for at least one week before sowing.

Sowing too early can result in vernalisation – where plants will be stimulated to flower and seed prematurely with little bulbing.  Later sowing may risk the germination rate due to lack of soil moisture and shortens the growing season impacting yield.

Fertiliser

High yielding fodder beet crops require high inputs of fertiliser or soil derived nutrients. The fertiliser management for fodder beet differs from brassicas.

Whereas brassicas have a high demand for nitrogen (N) and phosphate (P), fodder beet has a higher demand for potassium (K), magnesium (Mg) and Na.

All basal fertiliser should be applied pre-plant and not with the seed.

Weeds, pests, and diseases

Fodder beet seedlings are slow to establish and reach canopy closure making them especially susceptible to weeds and pests during early crop development.

In the early stages, fodder beet plants are very sensitive to chemicals: take care to avoid spraying during the heat of the day and ensure that tank mixes are compatible and that any threatening spray residues in the spray tank have been properly cleaned out. Problems can arise in crops with uneven germination as some plants will be at the wrong growth stage when chemical is applied.

The main pests are springtails, nysius, cutworm and slugs. Farmers are advised to inspect young crops regularly by walking into the paddock and apply appropriate insecticide if necessary.

The correct timing of chemical applications for weed control

The first spray is the pre-emergence/post planting spray – this is applied after drilling but before plant emergence. Apply as soon after planting as possible. An insecticide should be included in the spray. Two post emergence sprays generally follow this. Seek professional advice on what chemicals to use. There are new products available which allow very early [cotyledon stage] spraying options.

Yield and utilisation

Yields expected at 150 days under good management and good rainfall is approximately 15-18T DM/ha. Under good growing conditions (100kg DM/ha/day March-May) it is possible to have yields of around 25 tonnes in May-June in regions not limited by dry conditions.

For a fodder beet crop (costing $2500/ha) to break even, it would need to provide an extra 8t DM/ha (eaten) more than the pasture it was replacing. The yield differential of fodder beet versus pasture can result in a profitable option when all factors are considered.

Estimating fodder beet crop yield

Estimating fodder beet yield is important to accurate allocation. Determine the row spacing of the crop by measuring across ten rows of crop from the centre of the first row; divide the distance by ten.

• Collect at least five yield samples that are representative of the paddock.
• From each yield sample, remove all the plants from at least 4 lineal m of a row (50cm row spacing) or 4.44 lineal m (45cm row spacing). This length provides 2m² of sample. (2 and 2.22 m lengths = 1m²). In crops that are very uneven it is recommended that the sampling is modified so that the 4 lineal m comprises 2m of two adjacent rows.
• Remove any excess soil from the bulbs by scraping with a blade, separate the leaf and bulb by cutting as close to the crown of the bulb as possible and measure the wet weight of the leaf and bulb separately.
• Select approximately 300g of leaf from multiple plants and 3-5 bulbs for DM determination. Cut the bulbs in quarters lengthways and place one-quarter of each bulb into a plastic bag, seal and send with the leaf to the lab for DM determination. As DM% varies greatly between cultivars and paddocks estimating the DM% will result in under or overestimating the yield. The DM content and leaf-to-bulb ratio change during winter therefore paddocks should be yielded just prior to feeding.

1. 1. Calculate the DM yield for each sample and plant part, and average, fresh weight x DM%:
      • 30kg bulb x 0.14 DM = 4.2 kg DM and 6 kg leaf x 0.09 DM = 0.54kg DM 2.
   2. Add the average bulb and leaf DM yield together:
      • 4.2+ 0.54 = 4.74kg DM/2m² 3.
   3. Multiply by 5000 to determine the kg DM/ha yield:
      • 4.74kg DM/2m2 x 5000 = 23700kg DM/ha or 23.7t DM/ha

Considering the economics

When purchased from off-farm, the cost of supplements can be compared directly with alternative supplements. However, if grown on the milking platform the cost must be calculated based on the gain in crop yield above the amount of pasture that would grow in the paddock over the same time, i.e. the net yield = crop yield – lost pasture.

Costs associated with establishment:

• Spray out + glyphosate herbicide
• Cultivation
• Sow
• Seed
• Weed sprays (3-6 sprays)
• Insecticides (2-3 sprays)
• Fertiliser (fodder beet base, urea, lime)

Key points:

• Know paddock area and feeding face length.
• Accurately measure the yield and determine the square metres required, especially in the area where cows will be transitioned.
• Have dry matter tests done – DM% varies from paddock to paddock, farm to farm, month to month, year to year, and between varieties.
• Do not put hungry cows onto the crop.
• Offer supplement at least three hours before fodder beet is offered.
• Do not use a time-based approach on the crop when transitioning – cows can consume 3-4 kg DM/hour (i.e. 1 kg /15-20 minutes) when the break is first opened up.
• Transition onto the crop over at least 14-21 days, increasing the allowance by no more than 1kg DM every second day for cows and 0.5kg DM every 2-3 days for rising 1-year-olds.
• Pay attention to detail when setting up break fences.
• Have good power on the fences and always have a catch fence close to the break fence to minimise the impact of breakouts.
• Don’t forget to readjust the breaks if cows are removed.