Closed-loop variable rate applicator

Abstract

A closed-loop fertilizer application system capable of determining a soil prescription in near real-time, and dispensing fertilizer to the soil scene as a function of the soil prescription. The closed loop application system does not require the use of maps or navigation systems, but rather, ascertains a soil type and chemical composition on the go. In the preferred embodiment, the application system implements a spectrograph implementing the technology of spectroradiometry to determine soil type and present fertilizer composition in near real-time. An expert system determines the soil prescription based on the soil type and current fertilizer levels, and controls the dispensing rate of the fertilizer as a function of the vehicle speed. The soil analyzer is disposed a pre-determined distance forward of the vehicle such that there is adequate time to perform soil analysis, determine a soil prescription, and then dispense the fertilizer at the rear portion of the vehicle. The soil analyzer generates a soil signature in near real time, which signature is compared to a pre-determined reference soil signature stored in memory. The spectrograph radiates the soil at various pre-determined fixed frequencies which causes the various elements in the soil to fluoresce. Each fertilizer in the soil will fluoresce at one or more known frequencies, the amplitude of which is indicative of the percentage of the fertilizer present at the soil scene.

Dependencies are inferred from the claim text.