Cristalina pivot: 90 days of soil moisture data

A 90-day soil moisture monitoring study on a bean center pivot in Cristalina, Brazil (May 13 to August 14, 2026), with a soil probe taking hourly readings — 906 measurements total. The system captured 9 irrigation events with exact timestamps (plus 2 in gaps without transmission) and identified that the soil operates in a 35–40% moisture range, saturating around 50–52% and draining about 11 percentage points in the first 24 hours after each pass.

Crop water use between irrigations was measured at 1.14 percentage points per day in July (varying only ±12% across the six intervals, from 0.99 to 1.27 pp/day), with the soil spending 73.6% of the time within the ideal range since July 7. All 9 irrigation events with a recorded time occurred between 7 pm and 2 am — consistent nighttime operation, with no daytime passes.

The analysis identified two management opportunities: the moisture floor when the pivot turned on rose from 31.9% on the first pass to 36.8% on the last (indicating 1 to 2 days of still-available water storage when the pivot starts), and the irrigation peak hit the ~52% ceiling in 6 of 9 passes, suggesting that stopping around 46–48% would save water without losing usable storage. With the three learned numbers (35% floor, 1.14 pp/day consumption, and an average +14 pp jump), the report proposes an automatic irrigation alert via WhatsApp 24–48 hours in advance.