Furrow irrigation

An automated furrow irrigation control method comprising the steps of

• (a) initiating an intermittent irrigation flow into an upstream end of a furrow at a substantially constant water discharge rate;
• (b) periodically sensing progress of water flow along said furrow;
• (c) periodically adjusting intermittent discharge periodicity into said furrow in response to the sensed progress of said water flow so as to ensure a substantially continuous flow in said furrow at an overflow rate which lies substantially between .+-.30% of a constant value;
• (d) sensing arrival of said water flow at a downstream end of said furrow;
• (e) reducing said water discharge rate in response to the sensed arrival of said water flow at the downstream end of said furrow;
• (f) sensing percolation of said water flow at said downstream end down to a predetermined depth;
• and
• (g) terminating said irrigation flow in response to said sensed percolation.

An automated furrow irrigation control installation comprising

• (a) a flow control valve for controlling discharge of irrigation water into an upstream end of a furrow;
• (b) a control center for controlling operation of said control valve;
• (c) a plurality of water flow sensors adapted to be spaced along said furrow for sensing water flow along said furrow and coupled to said control mechanism;
• and
• (d) a flow depth sensor adapted to be located at a downstream end of said furrow and coupled to said control center;
• said control mechanism responding to output of said sensors so as to adjust water discharge rate from said valve so as to ensure a substantially constant flow rate in said furrow in an advanced stage and so as to terminate irrigation at an end of a soaking stage.

An automated furrow irrigation control system comprising:

• a valve for initiating an irrigation flow into an upstream end of a furrow at an initial water discharge rate;
• first sensor apparatus for continuously or periodically sensing progress of water flow along said furrow;
• control apparatus for continuously or periodically increasing the water discharge rate in response to the sensed progress of said water flow so as to ensure a substantially continuous flow in said furrow at a flow rate which lies substantially between .+-.30% of a constant value;
• second sensing apparatus for sensing arrival of said water flow at a downstream end of said furrow, the control apparatus being responsive to the second sensing apparatus by reducing said water discharge rate in response to the sensed arrival of said water flow at the downstream end of said furrow;
• third sensing apparatus for sensing percolation of said water flow at said downstream end down to a predetermined depth;
• and
• apparatus for terminating said irrigation flow in response to said sensed percolation.

An automated furrow irrigation control system comprising:

• a valve for initiating an intermittent irrigation flow into an upstream end of a furrow at a substantially constant water discharge rate;
• first sensing apparatus for periodically sensing progress of water flow along said furrow;
• control apparatus for periodically adjusting periodicity of intermittent flow into said furrow in response to the sensed progress of said water flow so as to ensure a substantially continuous flow in said furrow at a flow rate which lies substantially between .+-.30% of a constant value;
• second sensing apparatus for sensing arrival of said water flow at a downstream end of said furrow, the control apparatus reducing said water discharge rate in response to sensed arrival of said water flow at the downstream end of said furrow;
• and
• third sensing apparatus for sensing percolation of said water flow at said downstream end down to a predetermined depth, and terminating said irrigation flow in response to said sensed percolation.