Soil Restoration Simulation

Note

This is a visualization tool based on generalizations and estimates. It's primary purpose is to show the difference in depth of soil restoration between the Bison Underground Method using a Soil Restoration Tool once a year and conventional surface mulching or a control. Estimates for rates of change are based on observations made in our gardens and experimental sites. This is the first version of this tool, and broad generalizations are used, and there may be some errors. Many improvements and upgrades are planned for future versions, including comparison with rototilling, and improved aggregate formation visualization. 

Bison Underground · soil restoration · 3-year simulation

Soil Restoration Simulator

Same soil, same plants, two plots. Left: the Bison Underground tool each March. Right: the control. Drag the divider to compare.Each March the left plot gets the hand tool: narrow slots cut into the ground and filled with organic matter. The right plot gets nothing, or, if you choose, the usual fix: compost spread on top. Play the seasons and watch the soil below the surface change.

slot 8 in deep × 2.5 in wideslots every 9 in, new set each springeach plot 72 in long × 16 in deep · drag the divider to comparerun 3 years
Bison Underground plotBison Undergroundtool + compost · extract · worms
Control plotControlsame soil, 2 in surface compost each March
SpringYear 1 · early March

Starting soil

applies to both plots · changes rerun all 3 years
LoamUSDA texture class
Crop, both plots

Bison Underground plan

left plot only · applied each March
Fill with

Control plan

right plot only · applied each March
pauses at the end of each year
Now, Year 1 · early MarchBison UndergroundControlDifference
Organic matterBison UndergroundControlpick a row to chart it · drag on the chart to move through time

What drives the changes

Both plots run on the same rules. The only difference is what goes into the left plot each March.

Slots feed the soil from inside

Each slot is a column of food 8 in deep. Worms, roots and fungi carry it outward, so dark soil spreads from every slot. Alfalfa breaks down fast and feeds life quickly; compost lasts longer.

Life builds structure

Microbes glue soil into crumbs, and worms leave open burrows. More crumbs and burrows mean more pore space, so water and roots move down instead of sideways.

Slots break the pan

Silty and clay soils form a hard layer a few inches down. On the control side roots turn flat when they hit it. On the treated side they follow the slots down past 8 in.

Surface compost stays on top

Compost spread on the surface feeds the top of the soil and oxidizes to the air. The soil under it darkens from the top down, about 1 in per year, while slot fill starts 8 in deep and darkens outward from there.

Water follows the openings

A 1 in storm in 30 minutes arrives at 2 in/hr. Surface compost holds about 0.3 in of water per inch of depth; the rest passes through to the soil. Soil that takes in less than it receives sheds the rest, and under compost that runoff moves along the contact between the compost and the soil. Open slots and burrows let the treated side keep more of it.

This is a teaching model. Rates are simplified and tuned to show the direction and relative size of changes, not calibrated to field data. Plot-wide organic matter is measured in the soil between the slots, not in the slot fill.