Maximising the Value of Irrigation.

Maximising the value of irrigation with precision technologies

Carolyn Hedley^a, Jagath Ekanayake^a, Ahmed El-Naggar^b, Pierre Roudier^a

^a Landcare Research New Zealand Ltd.,

^b Massey University, New Zealand

Abstract

In New Zealand, variable soil, land and crop condition frequently occur under one irrigation system, and where precision technologies are implemented they allow management of this variability. The recent uptake of next-generation variable rate irrigation sprinkler systems is generating interest in new ways to improve scheduling, and our research has supported the introduction of these systems and focusses on the development of compatible decision support systems. Context for this research is underlined by the fact that globally freshwater use has been growing at more than twice the rate of population increase, and regions are reaching the limit at which water services can be sustainably delivered. Irrigation is a major user of allocated freshwaters globally, and many new irrigation schemes are being built in New Zealand to support global food security demands.

Our research has developed and tested wireless sensor technologies to provide soil and crop information in near real-time to remote end users via smart phone apps and webpages. This enables timing, placement and amount of irrigation to be optimised to local conditions at high resolution both in space and time. Research trial results indicate that decision support systems that use sensor mapping technologies with targeted soil and crop monitoring regularly provide water savings, typically 5 – 30%, but sometimes greater (depending on the degree of variability, which is site specific), reduced nutrient leaching, and with positive or neutral impacts on crop yield. The systems are also used innovatively by farmers for flexible management. Progress and results from on-farm variable rate irrigation trials will be reported in this presentation.