Structure of a Block

A block contains a header section which configures the block, followed by a sequence of management events. The general layout is like this:

block-number   Block # [block description]
block-header
block-events
END 

Each block in the schedule file starts with the following header lines in the order shown:

1.	block number and description		A block number, followed by the string Block # and an optional block description.
2.	last simulation year		Last year in simulation time for the block.
3.	number of years in the repeating sequence		The number of years within the block are described by block's management events.
4.	output starting year		May be any year greater than or equal to the starting simulation year.
5.	output month		valid values: 1-12
6.	output interval		Specifies how many times the output variables are written to the output file, in monthly multiples of 1/12 (0.0833). A value of 1 writes the output annually; 0.0833 (1/12) writes monthly output. The smallest valid value is 1/12. Alternative values for this field are the strings monthly and annual, which replace the values 0.0833 and 1.0, respectively.
7.	Daily output starting year		The simulation year in which daily output will begin. This is optional, but if present must be followed by "Daily output month". Century5 ignores this value.
8.	Daily output month		The simulation month at the start of which daily output will begin. Output will start at the first day of the month and will continue until the last day at the end of the block or simulation. This is optional; use only with the "Daily output starting year". Valid values: 1-12.
9.	weather choice for this block		For the weather choice, see the section Weather Data.

Structure of an Event

The events scheduled for this block follow the block header. Events consist of year relative to the start of the block (not simulation year); month in the block year; type of event (see Management Events). Each event has the format

year  month  event-type  [event parameters]  [# comment]

Some event types require additional data, such as CROP, which is followed by the parameter set name for the crop to be grown. The following example event has grazing at year 1, month 6, of type GM:

1 6 GRAZ GM

Events can be placed on the separate lines, or on the same line. For example, here are two block years:

1  1 CROP CPR  1  1 FRST  1 11 SENM  1 12 LAST
2  1 CROP CPR
2  1 FRST
2 11 SENM
2 12 LAST 

It is common to have mulitple event years in a block which are identical, with only the year differing. Rather than duplicate a year's events for subsequent years, you can use the keyword "repeat" following the year number, or a range of years. For example:

1 1 CROP CPR  1 1 FRST
1 5 GRAZ GM  1 6 GRAZ GM  1 7 GRAZ GM  1 8 GRAZ GM  1 9 GRAZ GM
1 11 SENM  1 12 LAST
2 repeat
3 repeat
4-6 repeat
END

If the event has additional data after the event parameter set name (GM in the previous example), and has more events following on the same line, then enclose all data after the event set name within single quotes or parentheses. For example:

1 6 EROD (0.01 1.1) 1 6 GRAZ GM

The last line of the block is the end of block marker END or using Century 4 style -999 -999 X.

Comments are text that is ignored. Comments lines begin with a comment character, one of [ # ! ; // ]. Comments in block events can also occur after the event information.

Example

For example, a series of historical farm practices might have been: breaking of the native sod in 1920, a wheat-fallow rotation with plow cultivation and straw removal until 1950, wheat-fallow with stubble-mulch management until 1980, followed by wheat-sorghum- fallow.

Block   Years          Management                          Repeating sequence
1       0 - 1919       Spinup: Grass with grazing          1 year
2       1920           Cultivation to break the sod        1 year
3       1921 - 1950    Wheat-fallow, plow, straw removal   2 years
4       1951 - 1980    Wheat-fallow, stubble-mulch         2 years
5       1981 - 1992    Wheat-sorghum-fallow                3 years