Drip Planner Chart: a simple irrigation scheduling tool for smallholder drip farmers

Drip irrigation is widely recognized as potentially one of the most efficient irrigation methods. However, this efficiency is often not achieved because systems are not always well designed or maintained and many farmers lack the tools to assess the crop water requirements and to monitor the soil moisture conditions in the field. There is a vast amount of literature on irrigation scheduling but little literature takes scientific information the next step by preparing practical guidelines for smallholder farmers. There is a large and widening gap between the state of the art irrigation scheduling tools and current on-farm irrigation practices. Most farmers find current irrigation scheduling tools overwhelming and lack the means and skills to install and operate them. It is suggested that farmers need simple, cheap and more comprehensive support tools to achieve improved irrigation management at the farm level. Wageningen University and Research Centre (WUR) developed the Drip Planner Chart (DPC) to provide smallholder farmers with a simple tool to schedule drip irrigation to the crops’ needs. DPC is a manual disk calculator to calculate daily irrigation requirement. Farmers’ feedback was the basis for developing the DPC. Using DPC over a three-year period in Spain resulted in a 14 % water saving and improved irrigation timing. Trials at smallholder farmer fields in Nepal and Zambia showed DPC advice is more adapted to the changing demands of the crop over the different growth stages and responds to the farmer’s quest for practical drip scheduling advice. This paper presents the Drip Planner Chart and the scientific validation of the accuracy of the DPC. Experiments on farmers’ fields show water saving in Nepal and improved yield in Zambia. In both countries an improved scheduling over the growing seasons was found using DPC

The efficiency of drip irrigation unpacked

Drip irrigation figures prominently in water policy debates as a possible solution to water scarcity problems, based on the assertion that it will improve water use efficiencies. We use this article to carefully trace the scientific basis of this assertion. Through a systematic review of the literature, we show that the term efficiency means different things to different people, and can refer to different elements in the water balance. Most articles claim that drip irrigation is irrigation water use efficient and crop water use efficient, but different studies use different definitions of these terms. In addition, measured efficiency gains not only refer to different capacities of the technology, but are also based on very specific boundary (scale) assumptions. We conclude that efficiency gains from drip irrigation will only be achieved under narrowly defined operational conditions, and just apply to very specific spatial and temporal scales. Hence, and unlike what generalized statements in policy documents and the overall enthusiasm for drip as a water saving tool suggest, expectations of increased water efficiencies associated with drip will only be realized, and are just realizable, in very specific circumstances

Beyond the Promises of Technology: A Review of the Discourses and Actors Who Make Drip Irrigation

Drip irrigation has long been promoted as a promising way to meet today's world water, food and poverty challenges. In most scientific and policy documents, drip irrigation is framed as a technological innovation with definitive intrinsic characteristics—that of efficiency, productivity and modernity. Based on evidence from North and West Africa as well as South Asia, we show that there are multiple actors involved in shaping this imagery, the legitimacy of which largely stems from an engineering perspective that treats technology and potential as ‘truths’ that exist independently of the context of use. Rather than ascribing the advent of drip irrigation as a successful technology to intrinsic technical features, this paper proposes to see it as grounded in the ability drip irrigation has to lend itself to multiple contexts and discourses that articulate desirable futures. We thus adopt a view of technology whereby the ‘real’ (i.e. the drip irrigation hardware) acquires its characteristics only through, and within, the network of institutions, discourses and practices that enact it. Such a perspective sheds light on the iterative alignments that take place between hardware and context and treat these as inherent features, rather than externalities, of the innovation process