1 composter a slice, one crop each · slices side by side · 18 blocks

Takes the crops out of a hopper line of mixed farm output and composts them, one crop a slice: build a slice for every crop your farm sends (each slice's filter hopper holds its crop); the bone meal drops into a chest under each composter and everything else runs on to the overflow chest at the end of the line, 111.4 items composted a minute.

Composting is random: each item fills the composter with its own chance (wheat seeds and kelp 30%, sugar cane 50%, wheat 65%), so the bone meal per crop varies from run to run; seven layers make one bone meal.

its first bone meal within 17 s · fits in 1×6×5

1 composter a slice, one crop eachAuto-composter3D view loading (or not available in this browser)

Try it

Watch the crops leave the line of hoppers into the filter hopper of their slice and drop one by one into the composter; the bone meal falls into the chest under it, everything else runs on to the overflow chest (the numbers over each container show what it holds).

How this design does it: One composter a slice, as many slices side by side as there are crops to compost: the line of hoppers along the top carries the farm's mixed output; each slice's filter hopper holds its crop (41 of it and four named papers), so it takes only that crop from the line, and a comparator reading it unlocks the hopper under it for a moment whenever one more arrives.

Build it

Download .litematic Download the design as text

The .litematic opens in Litematica (Minecraft 26.3): every block of the design in one region. The text file is the same build written as plain text, block by block.

Comes loaded with 105 wheat seeds and 8 paper in its containers: the download includes them; building it by hand, put them in first.

Blocks used: comparator composter hopper redstone torch redstone wire repeater stone

Details: how it works, measurements and properties

In depth

takes the crops out of a line of mixed farm output, one crop a slice, composts them and collects the bone meal in a chest under each composter; everything else runs on to the overflow chest

How to try it

The composter runs in the view: the farm's mixed output starts in the chest tagged ITEMS and travels along the line of hoppers; the slice's crop drops into the composter, the bone meal falls into the chest at OUT and everything else runs on to the chest tagged PASS (the overflow). The numbers over each container show what it holds; speed it up with the bar's speed dropdown. Drag to look around, pinch or scroll to zoom.

Measurements

metric	value	what it means
bone	meal/h per composter 100
items composted/min	111.4
bone	meal 22 from 368 items
first bone meal	by 17 s
hoppers awake	12	hoppers left unlocked at rest: each one looks for items every game tick (lag on busy servers)
at rest	yes	whether the build comes to rest once its work is done (no: it keeps running, like an elevator's clock)
blocks	per composter 18.0
tileable	every 1
bill	20 iron, 1 quartz, 10 redstone	what its blocks cost to craft: iron, quartz, redstone, slime

Notes from its designer

One composter a slice, as many slices side by side as there are crops to compost: the line of hoppers along the top carries the farm's mixed output; each slice's filter hopper holds its crop (41 of it and four named papers), so it takes only that crop from the line, and a comparator reading it unlocks the hopper under it for a moment whenever one more arrives. That hopper, kept full of the crop, drops one into the composter each time; the hopper under the composter pulls the bone meal out into the slice's chest. Anything no slice takes runs on to the overflow chest at the end of the line. A block on each line hopper keeps strays out (the input chest stands on the first).

Properties

Study	Auto-composters
Kind	Auto-composter
Blocks placed	18 (not counting the chests the view adds)
Box	1×6×5 (30 blocks of space)
Made of (the blocks that change state)	comparator, composter, hopper, redstone torch, redstone wire, repeater, stone
Inputs / outputs	no input / OUT
Design file	`compost-row`

The design file

on GitHub

Design file (58 lines)

# Auto-composter: 1 composter a slice, one crop each · slices side by side · 18 blocks
# https://vjeux.github.io/redstonepedia/circuits/compost/compost-row.html
name: compost-row
circuit: composter 1
tile: 1 0 0
port items: 0 4 0
port pass: 1 3 0
port output: 0 -2 0
origin: 0 0 0
palette:
  L minecraft:hopper[enabled=true,facing=east]
  A minecraft:hopper[enabled=true,facing=down]
  B minecraft:hopper[enabled=false,facing=down]
  C minecraft:comparator[facing=north,mode=compare,powered=false]
  S minecraft:stone
  T minecraft:redstone_wall_torch[facing=north,lit=true]
  R minecraft:repeater[delay=1,facing=south,locked=false,powered=false]
  r minecraft:redstone_wire[east=side,north=side,power=0,south=side,west=side]
  X minecraft:composter[level=0]
  O minecraft:hopper[enabled=true,facing=down]
layer -1:
  O
  .
  .
  S
  .
layer 0:
  X
  T
  S
  R
  S
layer 1:
  B
  S
  S
  S
  r
layer 2:
  A
  C
  r
  r
  .
layer 3:
  L
  .
  .
  .
  .
layer 4:
  S
  .
  .
  .
  .
nbt: 0 2 0 {Items:[{Slot:0b,id:"minecraft:wheat_seeds",count:41},{Slot:1b,id:"minecraft:paper",count:1,components:{"minecraft:custom_name":"filter"}},{Slot:2b,id:"minecraft:paper",count:1,components:{"minecraft:custom_name":"filter"}},{Slot:3b,id:"minecraft:paper",count:1,components:{"minecraft:custom_name":"filter"}},{Slot:4b,id:"minecraft:paper",count:1,components:{"minecraft:custom_name":"filter"}}]}
nbt: 0 1 0 {Items:[{Slot:0b,id:"minecraft:wheat_seeds",count:64},{Slot:1b,id:"minecraft:paper",count:1,components:{"minecraft:custom_name":"lock"}},{Slot:2b,id:"minecraft:paper",count:1,components:{"minecraft:custom_name":"lock"}},{Slot:3b,id:"minecraft:paper",count:1,components:{"minecraft:custom_name":"lock"}},{Slot:4b,id:"minecraft:paper",count:1,components:{"minecraft:custom_name":"lock"}}]}