Does precision irrigation help to reduce water consumption in agriculture?

Abstract

We have addressed mistakes and misconceptions often appearing in papers dealing with the rationale of water use in agriculture. We first explored main advances in water management allowing for precision irrigation in commercial orchards, and outlined the need for a professional management of hi-tech irrigation approaches. Then we analyzed limitations of the concept of water use efficiency (WUE), and its derivatives (intrinsic WUE, irrigation WUE), to assess the efficiency of irrigation water. We then focused on the two ways of using crop water productivity (CWP), i.e. as the marketable biomass or the net income per unit of water consumed by the crop. Here we addressed the difficulties of a proper use of the CWP concept by farmers and orchardists, especially when applied to super high density (SHD) fruit tree orchards (examples are given for a SHD olive orchard). Finally, we discussed on how the CWP approach to assess water saving in agriculture may yield different results depending on the scale at which it is used (plot vs. basin). Our findings outline the need for a more precise and rigorous use of both WUE and CWP for a correct assessment of water use in agriculture, especially in complex management systems related to the use of hi-tech irrigation.