The rate of deterioration depends on the type of mulch used. Pine bark seems to be the longest lasting raw material, lasting up to about 4 years. However, because of its acidifying effect on the soil, occasional use on very alkaline aoil is preferable.
RCW on a poorly accessible plot at Château Grillet
RCW and miscanthus straw degrade faster and take between one to two years on average. Wheat or barley straw degrades even faster taking only approximately 1 year. The process also depends on how thin the straw is. The thinner the plant, the faster it is degrades, meaning that a thicker layer of mulch is required.
As for living mulches, they usually dry out in early summer as water resources get scarce. If this doesn't happen, they can be mowed short a few times.
If the winegrower uses an endogenous mulch, they can resow after sheathing by putting the seed directly into the soil without tilling beforehand. This technique is known as direct seeding and it avoids having bare soil.
If there is already an established cover crop, the winegrower may use a specific seeder to seed directly. This cuts the established cover and puts the seedling in the right place with the help of a tooth attachment.
A seeding machine of this type is generally composed of a container (hopper) that can hold up to a hundred liters, placed on one or more rows of discs and tines. The width of the seeder is variable and can be adapted to suit the width of the vines.