Precision agriculture technologies such as sensors and mapping can be used to optimize fertilizer application in several ways, including:

Soil analysis: Sensors can be used to measure soil properties such as moisture content, nutrient levels, and pH. This information can be used to create soil maps that show variations in soil characteristics across a field. This allows farmers to apply fertilizer only where it is needed, reducing waste and ensuring that crops receive the nutrients they need to grow.

Variable rate application: Mapping technologies can be used to create prescription maps that indicate the precise amount of fertilizer required for different parts of a field. This information can be used to create a variable rate application system that adjusts the amount of fertilizer applied based on the specific needs of each area. This can reduce overall fertilizer use and improve crop yields.

Real-time monitoring: Sensors can be used to monitor crop growth and nutrient uptake in real-time. This information can be used to adjust fertilizer application rates throughout the growing season, ensuring that crops receive the nutrients they need when they need them.

Precision spraying: Mapping technologies can be used to create maps that show areas of a field where weeds or pests are present. This information can be used to create a precision spraying system that only applies herbicides or pesticides where they are needed, reducing the overall amount of chemicals used and minimizing the impact on the environment.

Overall, precision agriculture technologies can help farmers optimize fertilizer application, reduce waste, and improve crop yields, while minimizing the environmental impact of agricultural practices.

Precision agriculture technologies are tools and methods that help farmers optimize fertilizer application for crop production by collecting, analyzing, and utilizing spatial and temporal data on soil, crop, weather, and other factors.

Some of the uses of precision agriculture technologies for fertilizer application are:

• Sensors and mapping
• Variable rate technology (VRT)
• Controlled-release fertilizers (CRF) and stabilized nitrogen fertilizers (SNF)
• Water-soluble fertilizers (WSF) and liquid NPKs

https://timesagriculture.com/precision-agriculture-a-must-for-future-generations/

In the recent past some state agricultural universities under AICRP on Soil Test Crop Response Correlation project generated Georeferenced soil fertility maps for both macro and micronutrients and some general soil properties.These maps may help farmers to get fertilizer recommendations for targeted yields of important crops by by using site specific soil test values from the soil fertility maps.These maps can serve as alternative to regular soil testing by farmers to get fertilizer recommendations.