Site-Specific Management Factors influencing plant growth Water Light Temperature Soil Compaction Drainage

Tools Available Computers Complex but user friendly software Satellite guidance and positioning Application engineering advances

Schematic of steps involved in variable-rate technology Assessment Data collection Data Crunching Analysis Decision Making Action Production Measurement Evaluation

Variable rate –vs- Single Rate Why? Give Examples?

Grid Soil Sampling 1- Divide the field into grids Grid size ranges.5 – 4 ac. (1-2.5 most common) The small the grid the more accurate the field results will be. However, it is more costly, thus concentrate on the major

Management Zones Factor such as Topography/slope Soil color/type Drainage And other obvious field variables.

Remote Sensing “real time” picture of the crop and soil. Early example would be infrared photography. Satellite imagery (crop canopy reflectance) Chlorophyll meters Handheld or machine mounted sensors (infrared/near infrared monitors)

Enabling Technologies for site- specific fertilizer management GPS – Global Positioning System “constellation “ of satellites Three are needed to locate a point – x,y,z position & a 4 th for error correction. Geo-referencing = Field mapping software can utilized GPS for locating soil samples & boundary locations precisely.

Geo-referencing Provides: Accurate visualization of field variability. Control fertilizer equipment based on field position.

Enabling Technologies for site- specific fertilizer management cont. GIS – Geographic Information System Designed to take soil test information and GPS data. From this information it can generate geo- reference soil test maps, yield monitor maps, digital field images from satellite/aerial photography. “Layering” of field data. Allows you to analysis field variables and potential nutrient interactions.

Data Management Computers Internet Network (servers)

Site-Specific Fertilizer Application Equipment Can apply dry or liquid Can apply up to 10 fertilizer products at one given time Equipment with GPS guidance Controller (on-board computer) Collects and reads data, translator of field maps, direst applicator to apply the correct rate of fertilizer in the correct field location.

Economics, is it worth it? Must be determined on an individual based. Each is different. Will the cost go down?