Note: This page is no longer being maintained and is kept for archival purposes only.
For current information see our main page.
GWI Kurtz-Fernhout Software
Developers of custom software and educational simulations.
Home ... News ... Products ... Download ... Order ... Support ... Consulting ... Company
Garden with Insight
Product area
Help System
Contents
Quick start
Tutorial
How-to
Models

Garden with Insight v1.0 Help: Soil params options group

Update soil albedo: Yes' to recalculate soil albedo every day; or 'no' to 'freeze' the albedo at the last calculated value. Albedo is an estimate of the reflectivity of the soil surface to the sun's radiation.

Update soil cover index: Yes' to recalculate the soil cover index every day; or 'no' to 'freeze' the soil cover index at the last calculated value. The soil cover index is the fraction of the soil's surface covered by vegetation (alive or dead).

Update soil temperature: Yes' to recalculate the temperature of each soil layer every day; or 'no' to 'freeze' the temperature of each soil layer at the last calculated value.

Update water table depth: Yes' to recalculate the depth of the water table every day; or 'no' to 'freeze' the water table depth at the last calculated value. Water table depth is affected by daily rainfall, with some lag for the buffering effects of the soil.

Allow active humus organic N to be lost in eroded soil: Remove a quantity of active humus nitrogen from the first soil layer proportional to the amount of soil lost from that layer during erosion.

Allow active mineral P to be lost in eroded soil: Remove a quantity of active mineral phosphorus from the first soil layer proportional to the amount of soil lost from that layer during erosion.

Allow ammonia to be lost in eroded soil: Remove a quantity of ammonia from the first soil layer proportional to the amount of soil lost from that layer during erosion. (This was added and is not in EPIC.)

Allow decay of standing dead plant material to flat residue: Allow standing dead plant matter (above the soil) to decay to flat residue (in the soil).

Allow denitrification (loss of nitrate): Allow denitrification, the loss of soil nitrate to the atmosphere due to the creation of volatile products by anaerobic bacteria when the soil is waterlogged. Depends on soil water content and to a lesser extent on soil temperature and organic matter.

Allow flat residue to be lost in eroded soil: Remove a quantity of flat residue from the first soil layer proportional to the amount of soil lost from that layer during erosion. (This was added and is not in EPIC.)

Allow flow between active and stable humus N: Allow flow from active to stable nitrogen in the humus. An equilibrium equation based on a rate constant and on the number of years the soil had been cultivated when the soil patch was created (a parameter).

Allow flow between active and stable mineral P: Allow flow from active to stable mineral phosphorus. An equilibrium equation based on the assumption that at equilibrium there is four times as much stable as active mineral P. The flow rate is affected by the amount of soil weathering.

Allow flow between labile and mineral P: Allow flow from labile to active mineral P. An equilibrium equation based on the P sorption coefficient (PSP): the fraction of new labile P that tends to remain labile after an initial rapid sorption phase. PSP depends on pH and soil weathering.

Allow fresh organic N to be lost in eroded soil: Remove a quantity of fresh organic nitrogen from the first soil layer proportional to the amount of soil lost from that layer during erosion. (This was added and is not in EPIC.)

Allow fresh organic P to be lost in eroded soil: Remove a quantity of fresh organic phosphorus from the first soil layer proportional to the amount of soil lost from that layer during erosion. (This was added and is not in EPIC.)

Allow humus organic P to be lost in eroded soil: Remove a quantity of humus phosphorus from the first soil layer proportional to the amount of soil lost from that layer during erosion.

Allow labile P loss in percolation: Allow phosphorus leaching (as labile P) in water that percolates downward through the soil.

Allow labile P loss in runoff: Allow phosphorus leaching (as labile P) in water that runs off the soil surface.

Allow labile P to be lost in eroded soil: Remove a quantity of labile phosphorus from the first soil layer proportional to the amount of soil lost from that layer during erosion.

Allow lateral flow: Allow water loss from the soil by lateral (horizontal) subsurface (under the soil surface) flow.

Allow mineralization of active humus N: Allow mineralization of active humus N to nitrate by soil microbes. Reduced by factors that inhibit microbial activity: soil dryness, low soil temperature, and/or soil compaction (increase in bulk density). Humus P mineralization depends on this.

Allow mineralization of active humus P: Allow mineralization of organic phosphorus to labile phosphorus (by soil microbes). Depends on the same factors as does active humus nitrogen mineralization -- uses the same equation.

Allow mineralization of fresh organic N: Allow mineralization of fresh organic nitrogen (by microbes). Depends on soil water, temperature, and C:N and C:P ratios in flat residue. 80% of mineralized fresh organic N goes into nitrate, and 20% returns to active humus N as dead microbial biomass.

Allow mineralization of fresh organic P: Allow mineralization of fresh organic phosphorus (by microbes). Depends on soil water, temperature, and C:N and C:P ratios in flat residue. 80% of mineralized fresh organic P goes into labile P and 20% returns to humus P as dead microbial biomass.

Allow N uptake by plants: Allow plants to absorb nitrate from the soil.

Allow nitrate loss in lateral flow: Allow nitrogen leaching (as nitrate) in water lost by lateral subsurface water flow.

Allow nitrate loss in percolation: Allow nitrogen leaching (as nitrate) in water that percolates downward through the soil.

Allow nitrate loss in runoff: Allow nitrogen leaching (as nitrate) in water that runs off the soil surface.

Allow nitrate to be lost in eroded soil: Remove a quantity of nitrate from the first soil layer proportional to the amount of soil lost from that layer during erosion. (This was added and is not in EPIC.)

Allow nitrate to enter soil in irrigation water: Allow nitrate to enter the soil in irrigation water. The concentration of nitrate in irrigation water is constant.

Allow nitrate to enter soil in rainfall: Allow nitrate to enter the soil in rainfall. The concentration of nitrate in rainfall is a soil patch parameter.

Allow nitrification (ammonia to nitrate): Allow nitrification, the conversion of ammonia to nitrate (by aerobic soil bacteria). This depends on soil temperature, water content, and pH being at the best levels for aerobic bacteria to survive.

Allow organic matter to be lost in eroded soil: Remove a quantity of organic matter from the first soil layer proportional to the amount of soil lost from that layer during erosion.

Allow P uptake by plants: Allow plants to absorb labile phosphorus from the soil.

Allow percolation: Allow water to percolate downward through the soil.

Allow plant transpiration: Allow plants to pull water from the soil through transpiration.

Allow precipitation to reach soil patch: Allow precipitation to reach the soil patch surface and enter the soil patch.

Allow ridge settling from rainfall: Allow furrow dikes to settle, reducing their water-holding capacity, after each rain. Furrow dikes are raised ridges that keep rainfall from running off while the soil is saturated to control water runoff and erosion.

Allow runoff from irrigation: Allow water to run off the soil surface when the soil is irrigated and the soil is saturated with water. If this option is turned off, the water will remain in the soil although the soil could not possibly hold it in reality.

Allow runoff from rainfall: Allow water to run off the soil surface when it rains and the soil is saturated with water. If this option is turned off, the water will remain in the soil although the soil could not possibly hold it in reality.

Allow snowmelt: Allow snow on the soil surface to melt and run into the soil.

Allow soil evaporation: Allow water at the soil surface to evaporate and be lost from the soil.

Allow soil settling from rain: Allow the soil to settle after each rainfall.

Allow stable humus organic N to be lost in eroded soil: Remove a quantity of stable humus nitrogen from the first soil layer proportional to the amount of soil lost from that layer during erosion.

Allow stable mineral P to be lost in eroded soil: Remove a quantity of stable mineral phosphorus from the first soil layer proportional to the amount of soil lost from that layer during erosion. (This was added and is not in EPIC.)

Allow volatilization (loss of ammonia): Allow volatilization, the loss of ammonia to the atmosphere. For the top soil layer, is increased by higher wind speed and temperature. For other soil layers, is increased by low cation exchange capacity, high temperature, and proximity to the surface.

Allow water erosion from runoff from irrigation: Allow soil to be lost through sediment carried with water that runs off the soil surface from irrigation.

Allow water erosion from runoff from rainfall: Allow soil to be lost through sediment carried with water that runs off the soil surface from rainfall.

Allow wind erosion: Allow soil to be lost through wind erosion.

Allow nitrate to move to top soil layer from evaporation: Allow water moving up through the soil because of evaporation from the soil surface to carry nitrate with it.

Allow decay of flat residue: Allow flat residue in the soil layers to decay. Part (40%) of decaying flat residue returns to the atmosphere (as methane and other gases). The rest moves into organic matter, the most decayed carbon component in the soil layers.

Groups list

Home ... News ... Products ... Download ... Order ... Support ... Consulting ... Company
Updated: May 4, 1998. Questions/comments on site to webmaster@kurtz-fernhout.com.
Copyright © 1998 Paul D. Fernhout & Cynthia F. Kurtz.