Site specific irrigation management of a center pivot irrigation system using a sensor based decision support system

摘要

For farmers to take full advantage of center pivot Variable Rate Irrigation (VRI) systems, a decision support system (DSS) incorporating site specific irrigation scheduling methods must be integrated into their operation. This can be done with a Supervisory Control and Data Acquisition (SCADA) system implementing irrigation scheduling methods based on plant stress. This Irrigation Scheduling SCADA System (IS SCAD AS) has been effectively used for site specific irrigation management of center pivot VRI systems. The ISSCADAS automates the collection of data from plant and microclimate sensing systems, as well as the application of algorithms to process those data. A software, named ARSPivot (ARSP), has been developed to facilitate the irrigation management of VRI center pivots using an ISSCADAS. This paper describes how a sensor based DSS consisting of ARSP and the ISSCADAS was used in the summer of 2016 to operate a six-span VRI center pivot near Bushland, TX. Corn was planted on one half of the field (the other half was left fallow) with three deficit irrigation treatments: 100, 50, and 30% of full replenishment of soil water depletion to 1.5 m. Irrigations were scheduled using either manual weekly neutron probe readings or the irrigation scheduling method implemented by the ISSCADAS, which incorporated a set of thermal stress thresholds and varying irrigation amounts for each irrigation treatment. No significant differences were found between overall means of dry grain yield and crop water use efficiency at the higher irrigation levels. At the lowest irrigation level dry grain yield and water use efficiency of plots using the plant stress based method were greater and significantly different than those obtained with the neutron probe measurements.