Fertilizer

Fertilizer is a soft agricultural material used to boost crop production and support a few niche systems. It is primarily produced by the Fertilizer Synthesizer from Polluted Water, Dirt, and Phosphorite, and it can also be consumed directly by several buildings and creatures. At 125 °C, Fertilizer melts into Dirt, and it has a hardness of 2.

Its main farming use is as an input to the Farm Station, where Duplicants with the Crop Tending skill can spend Fertilizer to create Micronutrient Fertilizer and apply it to plants for a growth boost. This bonus increases plant growth rate by +100% for one cycle. It is most useful on crops with long growth times or on plants that require expensive normal growing conditions, since the fertilizer requirement does not double when growth is accelerated. Fertilizer has no effect on Mealwood.

Fertilizer is also a food source for Sage Hatch, which can eat up to 140 kg per cycle and converts it into Coal at a 1:1 ratio. In the Spaced Out! DLC, it can be loaded into rockets as a solid oxidizer. Its oxidizer efficiency is the lowest among solid oxidizers, but it is easy to handle and store compared with the alternatives. The downside is scale: a single trip can burn through hundreds of kilograms, which is a large amount of farm-ready material.

The Fertilizer Synthesizer produces Fertilizer continuously from Polluted Water, Dirt, and Phosphorite. A full-output setup produces 120 g/s Fertilizer and 10 g/s Natural Gas, using 39 g/s Polluted Water, 65 g/s Dirt, and 26 g/s Phosphorite. This works out to 72 kg per cycle, enough for 14.4 uses of Micronutrient Fertilizer. The machine is notably resource-efficient, with roughly half of the input mass ending up as useful fertilizer and the rest converted into gas.

• The synthesizer’s inputs can all be obtained renewably through ranching chains.
• Two tame Pips, two tame Dreckos, and two Pufts feeding an Algae Distiller can fully supply one Synthesizer.
• Because the synthesizer outputs Natural Gas, the gas can be burned for about 7.5 g/s Polluted Water and roughly 88 W of power.
• The machine can also function as a heat sink: if the input materials are warm enough, the total heat capacity of the inputs exceeds that of the outputs, allowing the process to destroy heat. Hot Polluted Water is especially effective, since heating solids is more cumbersome.

One quirk is that when Micronutrient Fertilizer is used on plants, Duplicants gain Machinery skill experience. This happens because the game treats the fertilization task as a Tinkering errand.