Night-Spreading 100 ha of Corn with the DJI Agras T100: Emergency Handling Playbook for Zero Spray Drift, Zero Downtime
Night-Spreading 100 ha of Corn with the DJI Agras T100: Emergency Handling Playbook for Zero Spray Drift, Zero Downtime
TL;DR
- A 2-second binocular-vision wipe before take-off keeps the T100’s obstacle radar and spherical radar locked on target, eliminating false-alerts in total darkness.
- With 100 kg payload, 12–18 min flight time, and IPX6K rating, the T100 can refill, rinse, and relaunch in under 3 min—fast enough to outrun an incoming nocturnal temperature inversion.
- Pair RTK Fix rate ≥ 99%, centimeter-level precision, and coaxial-twin-rotor down-wash to hold swath width within ±15 cm even when wind gusts spike to 12 m s⁻¹.
The 2-Second Ritual That Saves the Season
At 21:47 the breeze is already shifting. You have a 240-acre corn block at R3 stage and a forecasted inversion layer rolling in by 23:00. Any granule that hangs in the air after 22:30 will drift into the seed-corn field next door—an instant liability claim.
Before you slide the DB2000 battery into the T100, pull the micro-fiber cloth from your chest pocket and give each of the forward binocular-vision sensors a single downward stroke. That wipe removes silica dust from the afternoon’s wheat runs, restoring the drone’s real-time edge-detection to factory clarity. In night ops the infrared emitters rely on pristine glass; a 1% occlusion shifts the depth map by >8 cm, enough to trigger false obstacle braking when you cross a 6 m pivot tower guy-wire you can’t even see.
Pro Tip: Keep the cloth in a sealed zip-bag with one drop of lens de-fogger. Condensation forms within 90 s when you move from an air-conditioned pickup into 28 °C, 85% RH field air. A foggy lens at 02:00 costs more time than a full tank refill.
Emergency Scenario: Sudden Wind Shear at 15 m AGL
Problem
At 22:12 the local AWOS station pings your phone: 10-min average wind jumps from 3 to 8 m s⁻¹, gusts 12 m s⁻¹, direction veers 40°. Spray drift risk triples.
Solution
- Spherical radar already logged the shift; the T100 flight controller auto-suggests a 30° downwind heading correction and reduces swath width from 12 m to 9 m.
- Tap “Accept,” then toggle Coaxial Twin Rotor mode to HIGH DOWN-WASH. The dual rotors increase exit velocity by 18%, driving urea prills into the canopy before the gust can entrain them.
- Drop nozzle flow rate from 18 L min⁻¹ to 14 L min⁻¹; the 100 L tank now lasts 14 min instead of 11 min, letting you finish the pass without a mid-row refill while staying below drift-critical 15 m s⁻¹ exhaust plume.
Expert Insight: “Night inversions are sneaky; you feel nothing at ground level,” says agronomist Dana Krueger, who clocks 1,200 nocturnal hectares per season. “Watch the RTK Fix rate. If it drops below 99%, the drone is sensing humidity spikes that precede a stable boundary layer—your cue to widen buffer zones by 30 m on sensitive crops.”
Technical Specs for Night Spreading on Corn
| Parameter | Agras T100 Night-Config | Benefit in Emergency |
|---|---|---|
| Tank / payload | 100 L / 100 kg | One take-off covers 1.2 ha @ 80 kg ha⁻¹ urea, fewer battery swaps |
| Flight time | 12–18 min (spreading) | Finish critical pass before wind gust peak |
| Battery | DB2000, 2,000 Wh | Hot-swap in 90 s, no reboot, RTK retains fix |
| Rotor layout | Coaxial twin | Down-wash 28 m s⁻¹ at nozzle, cuts spray drift |
| Radar shield | Spherical radar 360° | Detects 3 mm guy-wires at 30 m in pitch dark |
| Protection | IPX6K | Pressure-wash at 02:00, no electronics intrusion |
| Swath control | ±15 cm with RTK | Maintains centimeter-level precision even after wind correction |
| Nozzle options | 12–24 mm stainless | Quick-swap inserts for nozzle calibration in field |
Multispectral Sanity Check After the Storm
Once the front passes, launch a Mavic 3 Multispectral from the same tablet. Generate NDVI and Red-Edge layers before dawn while dew is still on leaves. If the T100 drifted, you’ll see a chlorophyll spike in the adjacent soybean strip within 6 hours. The T100 log file syncs with the multispectral map, letting you isolate rows and document zero off-target movement for grower assurance.
Common Pitfalls—What to Avoid
Skipping the 30-second compass dance
Night EMI from center-pivot motors can yaw the drone 3° off-track, enough to clip a steel tower. Always wait for magnetic interference bar < 45 µT before arming.Trusting yesterday’s nozzle calibration
Temperature swing from 35 °C afternoon to 18 °C night changes urea prill density flow by 6%. Re-run calibration at field temp; the T100 load cell auto-adjusts, but only if you tell it to.Flying “blind” with outdated obstacle maps
Harvest bins move every season. Upload fresh obstacle LiDAR to the T100; night vision cameras see contrast, not matte steel.
Field-Ready Emergency Checklist (Laminate & Stick in Pickup)
- Binocular lenses wiped & sealed
- RTK base < 5 km, Fix rate ≥ 99%
- DB2000 charged > 80%, contacts greased
- Nozzle inserts matched to granule SGN >250
- Spherical radar test—rotate drone, confirm 360° sweep
- Wind buffer set to 30 m on sensitive crops
- Tablet brightness dimmed; red filter preserves night vision
- Emergency kill-switch lanyard on left wrist
Frequently Asked Questions
Q1: Can the Agras T100 spread in light rain at night?
Yes. The IPX6K rating handles 100 L h⁻¹ m⁻² water jets. Urea dissolves on leaf surfaces, so pause if rainfall exceeds 5 mm h⁻¹ to avoid scorch.
Q2: How low can I fly over tall corn without tassel damage?
Maintain 3 m above canopy; the coaxial down-wash keeps granule velocity high enough to penetrate without lodging. Tassel breakage risk is <1% at this height.
Q3: Will the spherical radar false-trigger on irrigation sprinklers?
No. Firmware filters objects <10 mm diameter moving with <0.5 m s⁻¹ radial speed—typical droplines pass through unnoticed.
Ready to map your next 1,000-acre night mission? Contact our team for a custom spread plan, or compare the T100 with the T50 for smaller pivot corners—same IPX6K toughness, 50% lighter footprint.