Baling – Four steps to a perfect bale

You have mown the grass and it has hit the target dry matter content. Now it’s time to bale, bind and wrap. So what is the best approach? 

1. Preparation

Before baling, it is always a good idea to lift and spread the grass with a tedder or a rake. If you don’t, the crop will flow through the pick-up unit lengthwise and will have no, or only little, contact with the knives. Then pay attention to one of the most vital components of creating a good bale – the swath. Ensure the swath is the same height and depth across the entire width. A guideline for swath width is 100-130 cm.

2. Machine settings

Setting the baler-wrapper starts at the pick-up. It is very important to avoid the pick-up tines disturbing the soil, otherwise crude ash can cause contamination in the bale. On the other hand, the loss of valuable grass must be minimised. Due to the working width of 230 cm, it is impossible to prevent the pick-up from being slightly too low at some points. So aim for a height setting somewhere in between. Adjust the height of the pick-up using the holes in the side. Simply set the desired height by pushing a pin into one of the holes. When the pick-up has been set to the right height, set the stretch film tension on the binder. Set the stretch tension using a pulley (V-belt) located on the side behind the binder. With film binding we recommend turning the pulley completely clockwise to close it. The stretch is 55% in front of the binder, with a further 15% stretch behind the binder if the pulley is closed. If the bales are bound in net, do not fully close the pulley. Depending on the quality of the net, a stretch of 5-7% is optimal. Once you have made the right settings, select the number of knives on the rotor. Depending on the version of the baler and wrapper combination, the choice is 14 or 23 knives. The number you select depends on the required cutting length: 70 or 40 mm. 

3. Setting the terminal

Set the baling pressure on the terminal in the cab. A high baling pressure creates a solid, dense bale with a firm outer layer. This makes the bales easy to handle and stack1.  We recommend using at least three layers of film to retain good bale stability. Whether you use net or film for binding, it is important to cover the bale across the width as well as possible, until just over the edges. This ensures a solid bale and reduces the risk of damage. 

4. Baling

The pick-up height has been set, the film stretch tension is correct, the baling pressure is good and the required number of film layers has been entered. Time to start baling! For the best possible bale shape and stability, make working passes that alternate between running along the left and right side of the swath. This ensures the sides of the bales are also filled properly. If the machine features a left-right indication option, use this in the final stage of baling for an even better result. Although a constant working speed is best to form a tight bale, the working speed should not be too high. The baler needs enough time to compact and form a dense bale. ’Stuffing’ the machine at high speed is counter-productive. If the bales are wrapped, 3D wrapping is preferable. This system wraps the cylindrical surface of the bale first which forces more oxygen out of the silage. This helps maintain the shape and protects the edges of the bales. 

Minimising impurities in forage

When harvesting forage, it is important to minimise impurities in the feed. Impurities not only have a negative effect on feed quality, but also on milk and meat production and therefore a farm’s profitability.  

In practice, one of the main problems is soil particles in the forage. This can compromise good storage properties. In addition, it can also negatively affect the nutritional feed value, so it is less easily digested by the cows. Particularly in periods of wet weather, baling the grass properly can be a huge challenge. Not only the grass, but also the ground has a low traffic bearing capacity and can be severely affected. This is because sunlight and air cannot penetrate down to the soil. A heavy crop of flattened grass must also be cut short, which brings a high risk of trapping soil particles in the harvested forage

Impurities in forage cause lower milk and meat production 

Soil contamination in forage can be considered as external ash content as it adds no nutritional value for the livestock. Higher ash content may also lead to reduced efficiencies in milk and meat production and therefore reduced overall economic efficiencies. It can also lead to quality losses during storage and increases the risk of heating in the bale, which would then have to be compensated for by adding extra concentrates into the ration. The forage can become less palatable for the livestock  so their overall intake may reduce. 

The economic impact of forage contamination can be considerable. For example; forage that contains 4% of soil impurities represents an energy loss equivalent to approximately €48 per hectare. Therefore the decrease in the cow’s energy intake due to impurities is equivalent to €27 per cow per year.

Adjust machinery to prevent impurities in forage

Several factors are important when mowing, tedding and raking grass. First, ensure that damage caused by field operations is avoided. Mowers, tedders and rakes must be levelled on a flat surface. The working height must be determined and set in the field. Do not cut too short, but maintain a cutting height of 7 centimetres, so that later during harvesting, the baler will not need to be adjusted too low to pick up the grass.  

Mowing and crop collection method essential for good bales

Mowing and leaving the crop spread across the field or raking the grass into a swath immediately. The first method is more common, although mowing and then creating rows is attracting more interest due to changes in grass composition and climate influences. Which of the two mowing methods is used is not that important as long as you follow the correct steps to create a good bale.  

The rule of thumb for the optimal moment to mow is just before the crop starts to bloom1. At that moment, the grass has a crude fibre content of 22 to 25% per kg of dry matter. That percentage can increase by 3 to 8 grams a day in the most important growth phase. At a higher fibre content, the digestibility of the organic matter decreases, the FUM is then lower2. For optimal ripeness of the grass, the soil and the plant itself must be as dry as possible. If it’s raining or the grass is still covered by heavy dew, it’s best to delay mowing for a while. If the grass is harvested too wet, silage preservation and palatability for the cow will be compromised. A dry matter content of 35 to 45% is optimal for good preservation and for good forage for the cattle.

Mower higher to reduce impurities in the bale  

To encourage the best possible regrowth of the grass, the stubble should be around eight centimetres high after mowing. If there are a lot of irregular patches in the grass, maintaining a stubble height of nine centimetres is an excellent option. Mowing too short is not recommended as this increases the risk of impurities in the bales. A lot of soiling and impurities in the bale also cause a slow pH decline during preservation. In addition, a high crude ash content allows butyric acid to develop, which has a negative impact on the feed value.   

Set machines for a good swath

The best way to set the working height of machines used to harvest forage – tedders, rakes and mowers – is on a flat surface4. A level, hard surface in the yard is the ideal place. In this way, you can quickly check if the tines on the tedders and rakes are at the correct working height and if there are no bent tines. On mowers, check the ground pressure, the lifting device and the knives. Set the machine, drive to the field and examine the settings critically again.  

Maximising baler performance

The shape and width of the swath are vital to maximise the performance of your baler. The correct swath shape is rectangular5. Remember that the centre of the swath should not be much higher than the sides. This shape ensures the bale chamber is filled better, including in the corners. If all the bale chamber is filled, the majority of air pockets will be removed from the bales, which improves the quality of preservation. An additional advantage is an evenly loaded intake across the entire baler width for maximum capacity.  

When the crop is baled, the correct swath width is approximately 150 cm. Depending on the baler pick-up width and field conditions, for example baling on slopes, it may be necessary to form a narrower swath for optimal bale formation.  

How does KUHN make a good bale?

The KUHN FBP (fixed chamber) and VBP (variable chamber) baler-wrapper combinations have a number of unique features that always create the perfect round bale. Even cutting quality, correct bale density, consistently filled bales, stable shape retention and firmly wrapped are what you can expect from bales produced by the KUHN FBP and VBP series.

Making a good bale is not easy in all conditions. We will address the main components of KUHN baler-wrapper combinations that contribute to a good bale despite changing crop conditions.

KUHN INTEGRAL ROTOR for quick and optimal crop intake

The pick-up tines cleanly collect the grass and feed it directly into the INTEGRAL ROTOR. The large augers on both sides of the rotor force the grass through the OPTICUT cutting rotor. This integral rotor facilitates a more consistently filled bale, uniformly filled right to the sides. The integral rotor is located just after the pick-up unit. This short distance maintains a short and compact inlet channel which guarantees quick crop intake.

After the rotor, the grass passes through the OPTICUT cutting system. Two options are available with a maximum of 14 or 23 knives. The operator can pre-select the number of knives used by retracting some of the knives in the inlet channel. Baling without knives is of course also possible. The knives are individually protected against foreign objects. This gives better cutting quality with as large crop throughput as possible and reduces the sensitivity of the knives to foreign objects. Less downtime and a better cutting quality.

KUHN bales retain their round shape

After the cutting system, the grass is fed into the bale chamber. In the balers with a variable chamber, the triangular starting chamber and the PROGRESSIVE DENSITY system guarantees the bale always forms correctly. The belts apply pressure on the bale from the starting core to the outer layers, maintaining a consistent bale pressure throughout the entire baling process, ensuring tightly formed bales that retain their shape. This ensures that a good, round bale can even be made with short, dry silage. Thanks to the variable chamber design, you can set the bale diameter yourself to range from small and manageable bales to large bales with savings on (wrapping) film.

The fixed bale chamber is designed with 18 fixed rollers, allowing the bale to rotate immediately as the chamber is filled. Sensors in the hydraulic tailgate cylinders help to achieve the correct bale density, bale size and bale fill (left/right). Binding the bales on both the FBP and VBP balers can be done using either net or film.

Film always correctly positioned thanks to the KUHN 3D wrapping system

After binding the bale, it is quickly transferred to the wrapping table without being damaged. This is particularly important if film binding is used. For this reason, after film binding, KUHN uses guide rollers on the bale transfer system that ensure the bale is transferred undamaged straight onto the wrapping table, then wrapping can start.

All VBP and FPB balers can be equipped with the optional, innovative 3D wrapping system. The rolls of film rotate a quarter turn after which the bale is first wrapped around the cylindrical part and then around the flat ends. The result is an evenly wrapped bale that retains its shape better than a conventionally wrapped bale. The 3D wrapping system ensures the film is correctly positioned and evenly distributed over the bale and the vulnerable bale shoulders are well protected. Thanks to the low height of the wrapping table, the bale can then be safely discharged without dropping or deforming it. This will ultimately benefit the storage capabilities of the bale.