Ultracompost is the most potent version of compost and is used in conjunction with the Farming skill. It is created by filling a compost bin with 15 buckets of dragon manure and then collecting it with empty buckets after the composting process is done.
A plant that has been treated with ultracompost has a 7% chance of dying, half that of supercompost, which has a 14% chance. Despite what its examine text may suggest, ultracompost does not make crops grow faster. This means that if the seeds cost more than 14 buckets of ultracompost (the inverse of 7%) or 476,574 and the patch would be unprotected, it is worthwhile.
For herb, hops, and allotment patches, using ultracompost will increase the number of harvest lives by three (from a starting number of three lives). Every harvest action will roll a chance out of 255 on the specific patch's "Chance to Save" table, taking one of the harvest lives from the patch if it does not hit, with the patch becoming empty when it runs out of lives. This chance is dependent on Farming level and other boosts (magic secateurs, greenfingers aura, juju farming potion, master farmer outfit, etc). Compared to supercompost which increases harvest lives by two using ultra compost will increase yield by 20%.
If the "Dragon Ultra Combo" totem perk is active at a player-owned farm's large pen, the player has a 1/1,000 (tier 1) or 1/750 (tier 2) chance to receive an ancient effigy while checking a farming patch that has been treated with ultracompost.
Ultracompost can be applied automatically by a tool leprechaun for 2,500 coins per bucket, provided that the payment has been made before clearing the patch, and that the leprechaun has some stored.
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