has multiple sub-locations. Pick one to view its timeline.

Location:

EcoSentry estimates your net impact on your local waterway by tracking both directions: nutrients you diverted by applying less than a naive baseline, and nutrients you contributed as surplus by over-applying. Honest in both directions. Here's the model:

EcoSentry uses your location's latitude and longitude (captured when you pick an address) and queries the USGS Watershed Boundary Dataset via the National Map service to identify the HUC12 watershed and waterway your property drains to. The system works for any location in the United States.

For each crop type, EcoSentry uses USDA NRCS estimates of what a naive untested gardener would typically apply per year (lbs of N and P per 1000 sq ft). Vegetables ~4 lb N; lawn ~3.5 lb N; trees ~2 lb N. These are conservative averages.

EcoSentry reads the amount and NPK percentages from every amendment you logged. Multiplying gives the actual pounds of N and P you applied to that sub-location.

For each nutrient, the difference = actual − baseline:

If actual < baseline → DIVERSION (positive): you applied less than a naive gardener. The unused amount times the loss coefficient is "kept out" of the waterway. Counted as a positive contribution.

If actual > baseline → SURPLUS (negative): you applied more than a naive gardener. The excess amount times the loss coefficient is what you added beyond baseline. Counted as a negative contribution.

Net impact = total diverted − total surplus. Green when net positive (good), red when net negative (over-applying).

25% of N beyond the right amount reaches waterways via leaching and runoff. 10% of P reaches waterways via erosion. These are USDA NRCS and EPA standard estimates for uncontrolled gardens, applied symmetrically to both diversion and surplus calculations.

These are modeled estimates, not measurements. Actual nutrient transport to waterways depends on rainfall, soil type, slope, ground cover, distance to water, and many factors we don't model. The numbers should be treated as directional: a net positive means you're meaningfully reducing your contribution; a net negative means you're meaningfully adding to it. Exact pounds are approximations.

Watershed boundaries: USGS Watershed Boundary Dataset via The National Map. Loss coefficients and naive baselines: USDA NRCS Agricultural Conservation Planning Framework.

The Soil Test Trends chart shows how your soil parameters have changed over time at this location. Each data point represents one saved soil test. The chart helps you see whether your soil is improving, declining, or holding steady across multiple test cycles.

Each colored line tracks a single parameter: pH (left axis, scale 3–9), and Nitrogen, Phosphorus, and Potassium (right axis, in ppm). Toggle any parameter on or off using the buttons above the chart. The Score line is hidden by default but can be turned on to track your overall soil health score alongside the nutrient readings.

Your Soil Intelligence analysis looks at your most recent test in isolation. The trends chart gives you the longer view. When a Soil Intelligence result recommends raising your phosphorus, for example, the trend line lets you see whether previous amendments already moved it in the right direction, or whether it has been flat for several seasons. Together, the two tools help you decide how aggressively to act on a recommendation.

If a parameter is trending in the right direction after logging an amendment, that confirms the amendment is working and you may not need to apply more. If a parameter is flat or moving the wrong way despite amendments, that signals it is time to retest sooner and revisit the product or rate. The amendment log and forecast cards on the Soil Memory Timeline are the companion view that explains why the trend moved the way it did.

Trends are only as reliable as your test frequency. A single data point is not a trend. Two or three tests taken at least 30 days apart begin to reveal a pattern. Seasonal variation is real: soil pH and nutrient levels shift with temperature and rainfall, so comparing a spring test to a fall test at the same location is normal, not a sign of a problem.

EcoSentry's forecasts predict how your soil will change over time based on the amendments you log. Here's what you need to know:

The engine takes a product's labeled effect (for example, lime's pH-shifting power per typical application rate) and scales it linearly by the actual amount you applied. So 10 lbs of lime should produce roughly double the shift of 5 lbs. The full effect is spread across the months it typically takes to work into the soil.

For lime and similar pH amendments, you'll see three forecast cards at 60, 120, and 180 days after application. These represent how the pH should change as the amendment reacts with the soil. For fertilizers, forecasts appear at 30, 60, and 90 days as nutrients release. Forecast cards automatically disappear once their target date passes.

If you apply the same type of amendment more than once at the same location within a stacking window, the engine combines them into a single forecast. The combined forecast accounts for the total amount applied across the stack.

Stacking windows by type: Lime, Sulfur, Gypsum = 60 days. Synthetic and Organic Fertilizer = 30 days. Compost, Manure, Cover Crop = 90 days. Mulch = 30 days.

When this happens, the older amendment card stays visible for your records but shows a small note: "Stacked with newer application above." The combined forecast appears under the newest amendment in the stack.

High = your baseline test is less than 30 days old, so the starting point is reliable. Medium = baseline is 30 to 90 days old. Low = baseline is more than 90 days old; consider retesting before trusting the forecast.

If a forecast predicts a value that would push your soil outside the ideal range for the crop on your baseline test, that forecast card gets a red border and a warning flag. Two cases:

Above ideal range: the amendment is predicted to over-shoot. Common when over-fertilizing or applying too much lime. Example: tomatoes want nitrogen between 50–150 ppm; if a forecast predicts 220 ppm, you'll see "⚠ Above ideal range for vegetables (50-150 ppm)."

Below ideal range: the amendment is predicted to under-shoot, leaving the crop short on a nutrient. Less common, but possible when an amendment pulls a parameter the wrong direction (e.g. lime on acid-loving blueberries).

Warnings are based on the crop set on the most recent test for that sub-location. If no crop was set, no warning will appear.

The engine does NOT yet account for: rainfall and temperature, soil buffering capacity (clay vs. sandy soils resist pH change differently), or amendments applied outside the stacking window (those are treated as independent applications and don't combine).

Treat forecasts as directional guidance, not lab predictions. They tell you "your soil should be heading in this direction by this time." The only way to know what actually happened is to retest your soil. EcoSentry will compare the prediction to the actual reading when you do.

Each amendment card has Edit and Delete links at the bottom right. Editing or deleting an amendment automatically recalculates the forecasts for that location, so the math stays consistent with what's logged.