You can see the current Maintenance amount on the right side of the screen (1). You can also see Maintenance Production and Consumption over time in the Statistics screen (2).
Maintenance is a crucial global resource that is required by vehicles and buildings to keep operational otherwise they break down and stop working. Maintenance level of each entity can be seen on the bottom of its window (1). In an emergency, broken entities can be instantly repaired using {0} (2).
With {0} being smelted, the {2} will produce <b>{1}</b>. {1} can be dumped anywhere on the island by placing dumping designations (unless you prevent {1} dumping by changing the <b>global dumping filter</b>). Trucks will always prioritize delivering {1} and other materials to where it is needed before dumping it (e.g. concrete production). Dumping {1} is important as typically your smelting industry will produce way more {1} than you can use. Dumping it has no pollution effect.
You can also give an increased priority to a storage that feeds your power plant. You must first have the <b>{0} slider</b> (1) moved away from the default location or you will not see the <b>priority selection screen</b> (2).
The priority of recipe execution depends on their order which can be changed using the arrows on the left (1). If you want to prioritize {0} processing over {1}, click the <b>up arrow</b> on the <b>{0} recipe</b> for it to move above the <b>{1} recipe</b>.
There are also diseases that can occur due to bad conditions in your settlement, for instance lack of clean water or too much trash. There are no diseases from pollution as pollution gives a health penalty directly.
Your population can suffer from diseases. There are diseases that just come and go and it is not possible to completely prevent them from happening. Providing healthcare can significantly reduce their negative impact.
You can also <b>leave the field empty</b> with no crop planted. This gives the soil time to regenerate fertility naturally but it won’t eliminate the same-crop fertility penalty on its own.
Growing the same crop more than once in a row will impose <b>{0} penalty</b> on fertility. This can be avoided by planting different crops in a crop rotation schedule. You can plant {1} which does not yield any useful products but helps to regenerate soil fertility and eliminates same-crop fertility penalty when planted between other crops.
Over time, crop fertility consumption and natural replenishment will stabilize at a value called <b>fertility equilibrium</b>. This value represents an <b>estimate of average soil fertility</b> based on the current growth schedule. The equilibrium exists because crop fertility consumption is constant but the natural replenishment speed increases as soil fertility gets lower.
Note that soil fertility does not affect crop water consumption or growth duration. This means that crops growing on more fertile soil will not only yield more but also will be more water-efficient (greater yield for the same amount of water).
Crop yield is based on <b>soil fertility</b>. If a farm has 50% soil fertility it will only have a 50% yield of products. Crops consume fertility as they grow but fertility is also naturally replenished over time (an empty farm would eventually reach 100% fertility).
Note that the higher your soil fertilization target is the lower the natural replenishment is. And once fertility climbs above 100%, the natural replenishment will turn negative which will require even more fertilizer to sustain it.
To make fertilizers work, you need to connect a <b>pipe with fertilizer</b> product to the farm (1) and drag the <b>fertility target slider</b> (2) to the desired level. The farm will automatically fertilize the soil to the selected level. Note that each fertilizer type has its own maximum fertilization target which is displayed in the <b>Fertilizers Overview UI</b>.
redsquirrel