Differences in soil, terrain, moisture, and plant condition are among the key challenges facing modern agricultural production. Applying the same fertiliser rates across an entire field often leads to overuse of resources and reduced economic efficiency. That is why differentiated fertiliser application is becoming a fundamental tool for cost optimisation and improving the accuracy of agronomic decision-making.
A practical case study by Swiss partner Pix4D demonstrated how Pix4Dfields can be used to transition to precision nitrogen fertiliser application and achieve significant financial savings without compromising plant health.
Project background
Nitrogen levels in grass or green biomass are a key factor influencing growth, protein formation, and chlorophyll development. The optimal concentration of this nutrient ensures a rich green colour and vigorous plant growth.
Conversely, nitrogen deficiency leads to yellowing and stunted growth, while excess nitrogen results in excessive elongation and reduced plant stability. Maintaining an optimal balance is therefore essential.
The study was conducted in the St. Augustine region of Florida, USA.
Data collection methodology
The study was conducted over a period of 2.5 years. The research team collected thousands of drone images and combined them with samples of St. Augustine grass tissue. This research made it possible to:
- apply fertilisers more accurately;
- reduce input costs;
- minimise the environmental impact of excessive nutrient application.
Project stages:
- a validation phase that lasted one year. During this stage, researchers developed a proprietary reflectance index based on drone imagery and confirmed the correlation between drone-derived index values and laboratory-tested nitrogen levels;
- an implementation phase that lasted a second year. At this stage, the results were applied in the field using Pix4Dfields software. Precision application maps were created, forming the basis for targeted fertiliser application, and economic benefits were documented in terms of cost savings and reduced tonnage.
In Pix4Dfields, application rates are set directly within the software environment to generate a Variable Rate Application (VRA) map. The completed map is exported directly to compatible agricultural equipment from various brands and can be used immediately in the field. This approach minimises manual operations and reduces the risk of errors during application.
Six months of practical application of the Targeted Operations tool in Pix4Dfields demonstrated a clear economic effect:
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average reduction in nitrogen application: 23 pounds per acre;
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total fertiliser savings (3,000 acres): 34.5 tonnes;
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financial savings (at $750/tonne): $25,875.
The results confirm that differentiated application can significantly reduce fertiliser costs without negatively impacting plant health. In addition to direct financial benefits, reducing excessive fertiliser use has a positive impact on soil and water resources. Targeted nitrogen application lowers the risk of nutrient leaching and supports more sustainable agricultural landscape management.
Variable rate application (VRA) of nitrogen to grass. The VRA prescription map was generated in PIX4Dfields and exported directly to the field sprayer for application
Spectral data and machine learning algorithms were used to generate task maps, providing nutrient estimates with accuracy close to laboratory measurements.
Key observations from spectral analysis:
- Red-Edge range — effective for estimating phosphorus (P) levels;
- Near-infrared (NIR) range — improves the overall accuracy of nutrient analysis;
- Green range — demonstrates high efficiency in predicting nitrogen (N) and potassium (K).
Conclusion
This Pix4Dfields case study demonstrates how the use of drone data, zonal analysis, and differentiated fertiliser application can directly impact the financial performance of agricultural production. Reduced fertiliser costs, optimised technological operations, and lower environmental impact make this approach a practical tool for modern agricultural producers.
Futurology is official distributor of Pix4D software. The brands' products are available through the Futurology dealer network in the United States of America. For more information, please contact info@futurology.tech.
