Abstract: A variable-orifice spray nozzle system includes at least one variable-orifice spray nozzle including a nozzle body with a flexible nozzle orifice opening and a mechanism that controls the physical size and shape of the orifice opening. An actuator can set and change the position of the orifice control mechanism. A mount attaches to a spray boom. The actuator has a home position. A pressure sensor senses fluid pressure delivered to the nozzle body. A controller can control the actuator to set a requested nozzle flow rate and/or droplet size based upon data from the pressure sensor via positioning of the actuator. The controller tracks the actuator position relative to its home position via open loop control. A weather control system senses weather conditions and is configured to adjust the requested nozzle flow rate and/or droplet size of the controller according to sensed weather conditions.

Abstract: A method for monitoring and controlling chemical concentration in a direct injection agricultural sprayer system monitors initial chemical concentration output from a chemical tank, carrier flow from a carrier tank, and mixed chemical concentration at nozzles of the spray system downstream of individual mixing points of the nozzles. Flow from the carrier tank and/or the chemical tank are controlled to target a set concentration at each of the nozzles. The initial chemical concentration establishes maximum concentration and a calibration curve for a chemical being applied and the mixed chemical concentration establishes an applied concentration in view of the calibration curve. A system is provided for the method.

Abstract: Automated fertigation systems and methods determine crop N status from a vegetation index calculated from acquired image data of indicator blocks having at least two plots, one with a reduced N application rate (canary) and one with an increased N application rate (reference) versus a bulk area N application rate. In a preferred method, sub-regions are defined in a field being managed. In each sub-region, N (nitrogen) is applied to create adjacent canary and reference plots, wherein a canary plot is given less than a designated N amount and a reference plot. The sub-regions are subsequently imaged. A fertigation decision is made for each sub-region based upon automatic analysis of the vegetation indices of the canary and reference plots in each sub-region.

Abstract: A method for monitoring and controlling chemical concentration in a direct injection agricultural sprayer system monitors initial chemical concentration output from a chemical tank, carrier flow from a carrier tank, and mixed chemical concentration at nozzles of the spray system downstream of individual mixing points of the nozzles. Flow from the carrier tank and/or the chemical tank are controlled to target a set concentration at each of the nozzles. The initial chemical concentration establishes maximum concentration and a calibration curve for a chemical being applied and the mixed chemical concentration establishes an applied concentration in view of the calibration curve. A system is provided for the method.