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Garden with Insight v1.0 Help: The next-day and end-year functions
The simulation proceeds by carrying out some calculations on a set of data for every simulated day. The
calculations are grouped into sets of instructions called functions. In brief, the simulation runs like
this:
garden next-day function
weather next-day function
(for each soil patch) soil patch next-day function
(for each plant in the soil patch) plant next-day function
In this section of the help system is a brief description of each of the functions, or sets of instructions,
called by the next-day functions. You might find that reading through these descriptions in order works
best, because later functions sometimes refer to things that were calculated in earlier functions. To read
through the functions in order, either keep returning to this page (using the Back button) or use the arrow
buttons to move through the functions.
Note that this description of the models is not complete, but a quick
run-through. If you don't understand these explanations, see the explanations from EPIC for more
information and look in any soil science, agronomy, or botany textbook.
garden next-day function
weather next-day function
interpolate long-term daily means from monthly means
calculate today's mean for maximum temperature, radiation, relative humidity
generate today's precipitation (if any)
generate today's minimum and maximum temperature
generate today's solar radiation
generate today's relative humidity
generate today's mean wind speed
generate today's wind direction
(for each soil patch) soil patch next-day function
add organic matter from pulled plants to mulch
calculate today's soil cover index
calculate today's albedo
calculate today's soil temperature for each layer
calculate today's wind erosion
if the mean temperature is above freezing,
melt some snow
calculate today's runoff and water erosion from rainfall
if the mean temperature is below freezing
add to the amount of snow on the soil patch
calculate the amount of nitrate that entered the soil in rainfall
calculate the amount of nitrate that entered the soil in irrigation water
calculate percolation and lateral flow
calculate potential soil evaporation
(for each plant in the soil patch)
calculate potential plant transpiration
calculate actual soil evaporation
recalculate water table depth
automatically irrigate if necessary
calculate runoff and water erosion from irrigation water
do nutrient cycling
(for each plant in the soil patch)
plant next-day function before water and nutrient allocation function
[if annual plant and one year old, die (if dead, leave next-day function)
accumulate vernalization units
if a seed, check to see if germination is complete
(if still a seed, leave next-day function)
accumulate heat units and calculate heat unit index
if perennial, check to see if should be dormant
calculate general temperature growth constraint
calculate leaf area index
calculate height and root depth
calculate damage from frost and short day length
figure if have died from frost (if dead, leave next-day function)
if not dormant or too cold, calculate root growth constraints for layers]
(back to soil patch)
allocate water to plants
(for each plant in the soil patch)
plant next-day function between water and nutrient allocation function
[if a seed, or dead, or dormant, or it is too cold, leave
if optimal water uptake chosen, change water use to optimal
calculate aeration growth constraint
calculate potential biomass increase (new growth)]
(back to soil patch)
allocate nutrients to plants
(for each plant in the soil patch)
plant next-day function after water and nutrient allocation function
[if a seed or dead, leave
if not too cold to grow and not dormant,
calculate general growth constraint
decide if should move to next stage of growth
figure actual increase in biomass
allocate new biomass among shoots, roots, fruits
decay fruits if old
if not too cold to grow (even if dormant),
reduce biomass if water-stressed and senescent
do drawing portion of next-day function
if just emerging from a seed, make first internode and leaves
if have just started reproduction, tell all plant parts to switch over
add new and remove lost biomass from plant parts
(for each drawing plant part) next-day function
meristem next day
internode next day
leaf next day
inflorescence next day
flower/fruit next day]
(back to soil patch)
automatically fertilize if necessary
calculate how much nutrient was lost in eroded soil
settle the soil if it rained
figure the nitrate carried up to the top of the soil during evaporation
remove eroded soil from the soil profile
End-year functions
Garden end year function
Weather end year function
calculate long-term adjustment factors
(for each soil patch) soil patch end year function
change pH for effect of fertilizations during year
attempt to auto-control pH
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