An agricultural harvesting machine comprising: a spreader for distributing and spreading a flow (B, C) of crop residue; an adjustable deflector plate operably extendable into the flow of crop residue to the spreader to redirect crop residue impinging the deflector plate; an actuator operatively connected to the deflector plate and operable to effect the extension of the deflector plate into the flow of crop residue; and a control system for automatedly controlling the positioning of the adjustable deflector plate to adjust and better balance the side-to-side flow of crop residue to the spreader and the distribution thereby, the control system comprising: - a plurality of sensors (82, 84, 86) arranged to monitor conditions at given locations and operable to produce sensor output signals corresponding to detected conditions at said given locations, information representative of crop residue flow (B, C) at certain positions across the width of the crop residue flow being determinable from said sensor output signals; and - a controller having a data input interface and a control output interface, said data input interface being coupled to said sensors (82, 84, 86) to receive data input signals corresponding to said sensor output signals, said controller being responsive to said data input signals to produce positioning control signals at said control output interface, said control output interface being coupled to said actuator to provide to said actuator deflector plate positioning signals corresponding to said positioning control signals; said actuator being responsive to said deflector plate positioning signals from said controller to effect adjustments in the degree of extension of the deflector plate into the flow of crop residue, whereby the controller is configured for controlling over time the degree of extension of said deflector plate into the flow of crop residue (B, C) to automatedly adjust the side-to-side flow of crop residue to the spreader, characterised in that: the spreader includes a pair of side-by-side spreader head assemblies operable to distribute crop residue being provided thereto; and said sensors include sensors (82, 84, 86) associated with the spreader head assemblies. a spreader for distributing and spreading a flow (B, C) of crop residue; an adjustable deflector plate operably extendable into the flow of crop residue to the spreader to redirect crop residue impinging the deflector plate; an actuator operatively connected to the deflector plate and operable to effect the extension of the deflector plate into the flow of crop residue; and a control system for automatedly controlling the positioning of the adjustable deflector plate to adjust and better balance the side-to-side flow of crop residue to the spreader and the distribution thereby, the control system comprising: - a plurality of sensors (82, 84, 86) arranged to monitor conditions at given locations and operable to produce sensor output signals corresponding to detected conditions at said given locations, information representative of crop residue flow (B, C) at certain positions across the width of the crop residue flow being determinable from said sensor output signals; and - a controller having a data input interface and a control output interface, said data input interface being coupled to said sensors (82, 84, 86) to receive data input signals corresponding to said sensor output signals, said controller being responsive to said data input signals to produce positioning control signals at said control output interface, said control output interface being coupled to said actuator to provide to said actuator deflector plate positioning signals corresponding to said positioning control signals; - a plurality of sensors (82, 84, 86) arranged to monitor conditions at given locations and operable to produce sensor output signals corresponding to detected conditions at said given locations, information representative of crop residue flow (B, C) at certain positions across the width of the crop residue flow being determinable from said sensor output signals; and - a controller having a data input interface and a control output interface, said data input interface being coupled to said sensors (82, 84, 86) to receive data input signals corresponding to said sensor output signals, said controller being responsive to said data input signals to produce positioning control signals at said control output interface, said control output interface being coupled to said actuator to provide to said actuator deflector plate positioning signals corresponding to said positioning control signals; said actuator being responsive to said deflector plate positioning signals from said controller to effect adjustments in the degree of extension of the deflector plate into the flow of crop residue, whereby the controller is configured for controlling over time the degree of extension of said deflector plate into the flow of crop residue (B, C) to automatedly adjust the side-to-side flow of crop residue to the spreader, characterised in that: the spreader includes a pair of side-by-side spreader head assemblies operable to distribute crop residue being provided thereto; and said sensors include sensors (82, 84, 86) associated with the spreader head assemblies. the spreader includes a pair of side-by-side spreader head assemblies operable to distribute crop residue being provided thereto; and said sensors include sensors (82, 84, 86) associated with the spreader head assemblies.