This post is intended as a compendium of current knowledge on farming that has been collected by me (Nerdicus) and Nero Would, with the help of information from Grumpus the Elder and others.
Farming Fact #1: Minimum farm fertility is 2% and maximum fertility is 99%
The fertility of a farm is calculated as the average fertility of the 9 squares under the farm plus 2%. If a farm has no meadow squares underneath but is placed with a meadow square touching one edge of the farm, the fertility of that farm will be 2%.
Farming Fact #2: Irrigation increases the fertility of a meadow farm by
40% and a floodplain farm by 20%.
An irrigation ditch must be within at least 2 squares of any square of a farm, and the increase will not push the fertility of the farm over the maximum of 99%. Irrigation to floodplain farms does not require a water lift, just start a ditch connected to the river.
Farming Fact #3: Each farm type is harvested during day #2 of its harvest
Each type of farm has a different harvest month and in the case of meadow grain, meadow barley, and meadow pomegranates are harvested twice a year. The harvest month of a floodplain farm is determined by the location of the city on the world map. Typically a city that is far south will have an earlier harvest month (because the inundation comes earlier). All farms send the harvest to the city on the second day of the month. See the table below for the specific harvest months of the various farm types.
Farming Fact #4: The yield of a farm is 800 * its production % complete.
The yield of a farm on harvest day is its production % complete rounded down to the nearest 1% multiplied by 800. An equivalent equation would be = Min( 800, (8 * Floor(Production Complete% * 100))). The function Floor() rounds down to the nearest integer. The function Min() selects the smallest value from a comma delimited list. The blessing of Osiris will double the yield of floodplain farms up to a maximum of 1600. A grain farm (both floodplain and meadow) will produce 100 straw no matter how small a harvest from the farm.
Farming Fact #5: Each 1/16th of a month a "Daily Gain" is added to a farm's
The current production % complete rounded down to the nearest 1% is displayed in the farms information window (right click on farm). Each day (1/16 of a month) the daily gain is added to the production % complete. The daily gain for a farm is calculated as = 0.05% * Max(1, Floor(Fertility% * 103.5 * 20 / 128)). The Max() function selects the largest value from a list and in this case enforces a minimum daily gain of 0.05% regardless of the farm's fertility. Nero Would noticed that this equation is equivalent to a basic farm production rate of 103.5 units per month for an ideal (and impossible) 100% fertility farm.
Farming Fact #6: A shortfall of farm employees affects meadow farm yield.
Like production buildings, a lack of staff causes the farm to yield correspondingly less product. While I have not calculated the exact shortfall I suspect the daily gain is multiplied by the current number of employees/10 (fully staffed meadow farm uses 10 employees). The above would be equivalent to the effects of employee shortfall on production buildings.
Farming Fact #7: A meadow farm will continue growing even if the cart pusher
does not return for harvest.
This is especially interesting for the biannual meadow farms. A meadow farm will continue growing up to 100% complete even if its cart pusher does not make it back for the next harvest. I typically have the barley meadow farms deliver their goods directly to the breweries. If I am overproducing barley, sometimes a cart pusher will not be able to deliver the barley and then return to the farm. Once he does return, the meadow farm will wait until the next harvest month before sending the cart pusher out with two harvests worth of product (up to the maximum of 800 units). For lower fertility meadow farms this means you can treat a biannual farm just like it was an annual farms for calculations like maximum distance to deliver goods.
The Farm Production Yield Table
I have designed this table to (hopefully) make calculating the expected yield of a farm easier. To use the table, just find the row with the farm's fertility and then move over to the column that describes the type of farm. The value at this location is the exact amount of product that you should expect when the farm is harvested. This value is the maximum and will only be reached when the farm has had a full staff for the entire season and started growing at the beginning of this growing season. Note that the biannual farms have two growing seasons per year and for some farm types the seasons are of different lengths. I would like to hear from anyone who has comments or has detected errors in the following. Im not great at color schemes or layout so comments on that are free game too.
|Fertility||Daily Gain||Floodplain||Biannual Meadow Farms||Annual Meadow Farms|
|Farm Product->||All Farms||Grain||Barley||Pomegranate||Chickpea
|Grow Months->||9 to 10||8||4||6||6||7||5||12|
|Farm Production Yield Table, Version 1.21 - Last updated 2000Jan19
Original formulas for farming production discovered by Nero Would.
This table's design and any errors care of Nerdicus.
|The following two equations are used to calculate this table's
values. The function Floor() rounds down to the nearest integer. The function
Min() selects the smallest value from a list, while Max() selects the largest.
Daily Gain% = 0.05% * Max( 1, Floor(Fertility% * 103.5 * 20 / 128))
Farm Yield = Min(800, (8 * Floor(Daily Gain% * 100 * 16 * Months)) )