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Tasmanian Institute of Agriculture

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Published: 24 Jun 2019

Fodder beet

Sam Flight, TIA

When it comes to fodder crops is sugar beet or fodder beet really that unbeatable? I recently attended a Seed Force Beet Field Day at Woolnorth, Circular Head to find out.

Before I outline the financial analysis, it is important I highlight the importance of getting the basics right. Crop yield is a very important determinant of whether the crop is going to cost you or make you money. There are a lot of things to get right to achieve a high yielding beet crop, but as was shown at the field day it is possible. Apart from the bulk of dry matter (DM) you produce if you get things right, beets also have high water use efficiency and withstand a large range of temperatures.

There are four key phases in growing a high yielding beet crop:

  1. Planning
  2. Preparation
  3. Planting
  4. Post establishment

Planning

Planning starts with identifying the end use for the beet and when you will require the feed, as this will determine the beet type to sow and the system requirements. This is something we do for all fodder crops, ensuring we match up feed type and maturity/ready for harvest time to the farm’s feed requirements.

Young dairy stock require a low bulb DM% for ease of eating to achieve good utilisation.  With adult dairy cows the beet DM% is not as crucial. Varieties giving early yield are important for feeding during the lactation.

Once the end user of the beets, heifers or cows have been decided on, you then need to consider how the beets will be harvested. Will it be a self-harvest or mechanical harvesting? If the stock are self-harvesting, grow beets that produce a higher proportion of the bulb above the ground surface, as this makes it easier for cattle to eat them. Leaf quality and retention is also an important factor with self-harvest. With mechanical harvesting the proportion of bulb above the ground is not as important, as uniformity of size and DM% has a bigger impact on harvest cost, losses and storage.

Another important decision is where on the farm to sow the crop. Consider paddock location, soil type, topography, and accessibility. It is important not to sow beets in the same paddock in consecutive years. Fodder beet is susceptible to chemical residues from many of the commonly used agricultural chemicals – be aware of the spray history for the paddock over the previous 12-15 months.

Planning a year in advance allows for the right preparation to be made for the crop.

Preparation

Beets are very sensitive to acid soils. Ideally, the pH should be at least 6.2. If the soil is below pH 6, it would be best to not sow the paddock until lime has been applied and the pH lifted. Ensure no root restrictions as roots will grow to a depth of 1.5 m in soils with no obstructions, e.g. compacted layers or hard pans. Deep cultivation should be carried out well in advance of planting to allow soil weathering and a weed flush.

Apply fertiliser after the main cultivation. Application of base levels of fertiliser should be based on soil tests and supply key elements for optimum plant establishment and growth. Fertiliser should be applied and incorporated as part of a last surface working. Timing should be at least 1 week prior to planting to help avoid burning the emerging seedlings. A beet plant has a crop requirement of 220-250kg N/ha for optimum growth. N mineralisation released from the majority of worked soils will contribute up to 80kg N/ha. The balance needs to be applied. The base fertiliser application should include 33% of the nitrogen requirement together with the other key fertiliser elements required.

Planting

Plant at 20mm depth into moist soils at a maximum ground speed of 5-6 km/h. Any faster can cause the planter units to bounce. Plant as early as soil conditions allow while considering risks such as the current climate and risk of vernalisation (bolting).

Determine the optimum plant field establishment per hectare for the end use. For in-situ grazing, aim for 80-90,000 established plants ha = 8-9 plants m2 (typically 90-100,000 seeds sown/ha). For mechanical harvesting aim for 100,000 established ha = 10 plants m2 typically 110-120,000 seeds sown/ha.

After planting apply post-planting pre-emergence herbicide. Consider combining multiple active ingredients to help ensure maximum weed control, while being safe for the emerging seedlings. Tasmania has limited access to suitable herbicides for beets, contact your local agronomist for advice on which is the most suited for your crop.

Post establishment

Correct timing of application of post-emergence pesticides and herbicides are crucial for both pest and weed control.  One large weed/m2 = 10% yield loss. Applications of pesticides should be customised to target the type of pest present and to suit the prevailing conditions.

The second application of nitrogen should be applied once the beets cotyledons have fully expanded. If this timing is missed, wait until the 8-leaf stage to apply as this will minimise the risk of plant burn. Nitrogen will help optimise plant growth and leaf expansion aiding maximum light interception. A further nitrogen application will be required at canopy closure; this generally should be the final 33% of the crop’s nitrogen requirements.

Risks (loss in yield)

Powdery mildew can cause up to a 20% yield reduction and is most commonly seen in dry environments. Rust can cause a 5-10% yield reduction and is most commonly experienced in moist damp environments. Cercospora (a fungal infection) can cause significant reductions in yield and is most commonly seen in warm/humid environments. Fungicides are not currently registered for use in Tasmania therefore, emphasis is required on ensuring the crop swiftly achieves canopy closure and by maintaining plant health through well timed nitrogen applications.

Beet yellow virus is prevalent in many areas where brassicas are grown, or aphids are present. This virus can cause major yield reductions if it is seen before the 16-leaf stage. If this virus is seen in later canopy stages the yield reduction potential is reduced.

Costing

At the field day, it was calculated the cost of growing beet crops was $4000/ha including the cost of seed, agronomy, fertiliser and sprays. Harvesting costs $1000/ha with an expected yield under irrigation of 20-30 t DM/ha yield or 13 cents to 20 cents per kg DM.

“Setting yourself up for good yields is key, as this becomes important when we go to cost things out…”

“Three key drivers for success are even germination, speed to canopy cover and maintaining a healthy canopy - it is the leaves that act as solar panels that promote continued growth, so we need to do this well”.

Fodder beets are a relatively expensive crop to sow – planning and management are critical in ensuring you get the yields needed to make it economically viable. If you aren’t going to do it properly, don’t do it at all.

This information is based on discussion at the Seed Force field day. If you plan on growing beets, always discuss with your agronomist to get specific information for your farm.

Comparison cost of grain, silage and beets

A

Feed Name

 

Grain

 

Silage

 

Fodder/sugar beet

B

Cost of Feed/Unit ($/unit)*

500

 

80

 

24**

 

($ per tonne or bale etc)

tonne

 

bale

 

tonne

         

C

Weight of feed unit (kg)

(eg: kg in a tonne or bale)

1000

 

630

 

1000

D

% DM in unit

 

0.88

 

0.45

 

0.15

E

Kg DM/unit

(C x D)

 

880

 

285

 

150

F

Cost ($/kg DM)

(B ÷ E)

 

0.57

 

0.28

 

0.16

G

Utilisation % of Feed

 

0.95

 

0.65

 

0.85

H

Cost of feed utilised ($/kg DM)

(F ÷ G)

0.60

 

0.43

 

0.19

I

MJ ME/kg DM

 

12

 

10.5

 

12

J

Cost /MJ ME (c/MJ ME)

(H ÷ I)

0.05

 

0.04

 

0.02

 

* Cost of feed needs to include the transport and feed out costs.

** Fodder beet cost is based on $4000/ha with a 25 t DM/ha crop. At 15% dry matter, this is 167 t/ha of beet (wet weight). It doesn’t

 

DM

CP

Ash

Sugar (Esc)

ME

Leaf

12%

18-20%

18-22%

 

10-11 MJ ME (depends on ash levels; if high, ME lower)

Bulb

15-22%

8%

15-25%

55-80%

12-12.5 MJ (max 13 MJ; also ash levels dependent; if ash high, ME lower)