Bales should be stored under conditions limiting water penetration soon after they are made. Re-wetting previously dry material leads to straw decomposition (rotting), bale disintegration and overall yield loss. Sisal twine is not known to last a long time when it comes in contact with the ground, so the less handling the better. Plastic net wrap and twine ensure better bale integrity during handling and transportation.
Round bales are less prone to water damage owed to their geometry, minimizing water percolation and subsequent retention. Square bales are easier to stack (Figure xvi) but they need to be covered as large flat surfaces absorb rain water, which would cause fibre decay during long term storage. Bales containing high value, properly retted stems for the textile industry have to be stored in sheds protecting the fibre from the elements.
It is worth remembering that according to the current Health Canada rules, only leafless and seedless hemp stalks are non-regulated materials that can be stored, transported and sold; therefore, post-harvest managements of hemp stalks (retting, drying, raking) should result in the removal of leaves and perhaps residual seed heads in the field before the bales are formed and stored.
Practical Bale Storing Tips:
- When stacking in the field, ensure that the bales are placed on a high area of the field with good drainage around the stack.
- Place the bales on sod or a layer of straw to help keep them dry on the bottom.
- The bales should not be placed on gravel as the small stones will imbed into the bottom side of the bale.
- Processing plants will have storage for a surge capacity and each has specific requirements on how the rest of the bales need to be stacked for storage.
- Pile all bales on the edge of the field where they are easily accessible to a truck at any time of the year. Contracting companies will not be responsible for crop that might get destroyed while picking up the bales.
- The bales can be piled at the edge of the field in a long tube if they are to be picked up soon.
- Pyramid style is not good if not covered. The snow and water collects or runs into the join in the bales, going into the bale and not shedding the moisture.
- Sheds or tarps may be required. Suggestion for tarp sizing when the bales are piled in a pyramid style (Figure xvii). Bales placed under a tarp will have moisture migration occur under the tarp. The bales need to be dry when going under cover and checked to ensure rotting does not occur especially at the top of the stack due to the moisture migration.
- Bales piled two on end and one lengthwise has been found to protect the bales for considerable time and in a wide range of conditions (T formation) (Figure xviii). Leave space between the rows to allow better air circulation and easier water runoff.
- Consult with your contracting company as to the system that is accepted for the plant.
Figure xiv – Hemp stalks retted for two weeks in the field
Figure xv- Baling of retted hemp, windrowed with a rotary rake
Figure xvi – Large square bales of grain type cv. Finola awaiting market opportunities
Figure xvii - Size of tarp required to cover bales of different diameter
Figure xviii - T formation way to stack in the Field