Robot or Human?
Crop spraying
Ground rig or crop duster (custom hire) vs Spray drone (hire, or buy and fly)
Whirrwork modelled estimates, not facts. Methodology · Track record
On these numbers people are clearly cheaper. The robot would sit idle most of the time; it pays off at higher volume or longer hours. Payback is longer than three years, which is longer than many robot contracts and some robot companies.
United States · USD · BLS OEWS May 2025 national medians by SOC occupation
Run your numbers
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Results
| Option | Per month | Per year | Per unit (acre) | Upfront | Payback | Break-even utilisation | 5-year NPV vs baseline |
|---|---|---|---|---|---|---|---|
| Human Ground rig (custom hire) Baseline | $1,450 | $17,400 | $8.70 | — | — | — | — |
| Human Crop duster (custom hire) | $1,975 | $23,700 | $11.85 | — | never | — | -$27,192 |
| Robot Drone spraying service | $2,131 | $25,570 | $12.78 | — | never | — | -$33,565 |
| Robot Buy a spray drone and fly it | $1,843 | $22,121 | $11.06 | $43,500 | 62 months | 16% Utilisation 11% |
-$14,154 |
What moves the answer most
Each bar shows the 5-year NPV of the best robot option when one input moves to the low or high end of its range, with the rest held at your values.
Cost per unit to 2035
Real terms (today's money). Robot hardware follows Wright's law; wages follow each country's history. Shaded band: robots-slow to robots-fast scenarios. Whirrwork modelled estimates, not facts.
Crossover year: after 2035 (2031–after 2035)
What the spreadsheet misses
- Safety
- No crushed crop or soil compaction; operators are near the chemical when mixing, as with any method.
- Quality
- Good on small, wet or irregular fields; ground rigs win on huge flat fields at high water volumes.
- Flexibility
- Drones fly when fields are too wet for a rig.
- Edge cases
- Drift, label rates and tank size limit what a drone can apply.
- Customer experience
- Neighbours notice less noise than a crop duster.
- Jobs and redeployment
- Creates operator jobs; custom applicators often add drones to their fleets.
- Regulation
- US needs FAA Part 107 plus Part 137 and a 44807 exemption for heavy drones, and state pesticide licences; other countries differ.
Related
- Crop spraying by drone Prices and providers for this job
- Essay: when robots beat humans on cost
- Projections
- Methodology
- API and MCP tool
- Research hub
Sources on this page
- 2025 Iowa Farm Custom Rate Survey: self-propelled ground broadcast spraying $8.70/acre average; aerial application $11.85/acre average (materials excluded) Iowa State University Extension and Outreach, 2025
- 2025 ASDC Impact Survey: US average custom drone spray rate $13/acre (down from $21 in 2024) American Spray Drone Coalition, 2026-01
- DJI Agras T50 from $19,999; spray-ready package $31,500 Southeast Drone Solutions (dealer), 2026-10 · vendor
- Occupational Employment and Wage Statistics, May 2025 (median hourly wage by occupation) U.S. Bureau of Labor Statistics, 2025-05
- Employer Costs for Employee Compensation, June 2026: wages and salaries 70.0% of private-industry compensation (series CMU2020000000000P) U.S. Bureau of Labor Statistics, 2026-06
- Mean nominal hourly earnings of employees by sex and occupation (ISCO-08), DF_EAR_EHRA_SEX_OCU_CUR_NB ILOSTAT (International Labour Organization), from national labour force and earnings surveys, 2025
- Labour cost levels by NACE Rev. 2 activity (lc_lci_lev): Germany 2022-2025, total labour cost vs wages and salaries per hour Eurostat, 2025
- Rates and thresholds for employers 2025 to 2026 (employer Class 1 NIC 15% above £5,000) HM Revenue & Customs, 2025-04-06
- 令和6年賃金構造基本統計調査 (Basic Survey on Wage Structure 2024), table 1 by occupation Ministry of Health, Labour and Welfare, Japan (via e-Stat), 2024-06
- Average monthly earnings of employees by sex and economic activity, DF_EAR_EMTA_SEX_ECO_CUR_NB ILOSTAT (International Labour Organization), 2022
- Average annual wage of employed persons in urban units in 2024 (by position and by region) National Bureau of Statistics of China, 2025-05-20
- Outsourced drone spraying in Brazil: BRL 60-150 per hectare Planon Ambiental, 2026-10 · vendor
- Drone fumigation in Mexico: MXN 300-800 per hectare, application only EAVision México, 2026-10 · vendor
- Euro foreign exchange reference rates (cross rates to USD), via Frankfurter European Central Bank, 2026-10-23
- Wright, T. P. (1936). Factors affecting the cost of airplanes. Journal of the Aeronautical Sciences, 3(4), 122-128 Journal of the Aeronautical Sciences, 1936
- Nagy, B., Farmer, J. D., Bui, Q. M., & Trancik, J. E. (2013). Statistical basis for predicting technological progress. PLoS ONE, 8(2), e52669 (62 technologies; Wright's law among the best hindcasters; errors grow with horizon) PLoS ONE, 2013