nutrient-analysis

name

nutrient-analysis

description

Interpret soil test nutrient data, identify deficiencies, query trends, and generate comparison reports. Use when asked to identify which fields need lime, find all phosphorus-deficient fields, compare nutrient values between tests, generate a before/after amendment report, or explain what a nutrient status means for crop production. Triggers include "which fields are deficient", "nutrient trend", "before after comparison", "lime recommendation", "N P K status", "improvement report", or any analytical question about soil chemistry data.

nutrient-analysis

Query and interpret soil nutrient data from soil-test-tracker to identify deficiencies, track improvement, and guide amendment decisions.

When to Use

• Finding all fields with a specific nutrient below optimal
• Comparing nutrient values between two different test dates
• Identifying which amendment corrected a deficiency
• Explaining what a status badge (low, deficient, high) means
• Querying trend data for a specific nutrient over time

Nutrient Status Interpretation

Deficient

Value is below 50% of the optimal low threshold. Immediate action is needed before planting. Crop yields will be significantly affected.

Examples: pH below 3.0, OM below 1.5%, P below 10 ppm

Low

Value is between the deficient threshold and the optimal low. Action recommended before next growing season. Minor yield reduction likely.

Optimal

Value falls within the low-high range. No amendment needed.

High

Value exceeds the optimal high threshold. Excess may lock out other nutrients. Avoid applying more of this nutrient.

Analytical Queries

Find all deficient fields

curl http://localhost:3004/api/analytics/field-summary

Filter in the response where any nutrient has status: "deficient".

Get nutrient trend for a specific field

# All nutrients over time
curl "http://localhost:3004/api/analytics/trends?field_id=..."

# Response includes per-nutrient arrays:
# { ph: [{date, value}], nitrogen: [{date, value}], ... }

Compare two specific tests

# Get both tests
curl http://localhost:3004/api/tests/{test_id_1}
curl http://localhost:3004/api/tests/{test_id_2}

# Calculate delta per nutrient
# delta_ph = test2.ph - test1.ph

Before/after amendment report

curl "http://localhost:3004/api/analytics/improvement?field_id=..."

Returns per-nutrient comparison between the test that prompted the amendment and the most recent test after it.

Nutrient Relationships

Understanding how nutrients interact helps interpret test results:

Situation	Cause / Solution
Low pH locks out Phosphorus	Raise pH with lime before adding P
High K competes with Mg	Balance K and Mg applications
Low OM reduces N availability	Compost and cover crops build OM
High pH (alkaline) causes Fe, Mn deficiency	Lower pH with sulfur
Very low CEC means nutrients leach quickly	Build OM to increase CEC

Amendment Matching

To find what amendment was applied for a specific deficiency:

# List amendments for a field
curl "http://localhost:3004/api/amendments?field_id=..."

# Filter by date range (after the deficient test)
curl "http://localhost:3004/api/amendments?field_id=...&from=2024-04-01"

Radar Chart Interpretation

The Analytics radar chart shows each nutrient as a percentage of the optimal midpoint:

• 100% = exactly at the optimal midpoint
• Below 100% = below midpoint (may be low or deficient depending on distance)
• Above 100% = above midpoint (may be high depending on distance)

A "balanced" radar shows all axes close to 100% with roughly equal extension.

Troubleshooting

Improvement report shows no change

The improvement report compares the test linked to an amendment (via test_id) against the most recent test after the amendment application date. If the most recent test predates the amendment, no comparison is possible. Add a new test after the amendment was applied.

Field shows different status than expected

The status is calculated server-side against the current optimal ranges at query time. If you change optimal ranges, previous test statuses are re-evaluated on the next query.