Feasibility study and cost-benefit analysis for increased water efficiency in Colombian palm oil production The project stimulates and supports the adoption of more efficient irrigation techniques by Colombian palm oil producers. To do so, the limiting factors for this adoption are (further) investigated and addressed in a feasibility study and indicative cost-benefit analysis. To convince producers to adopt these techniques, a pilot study is implemented at the experimental station of Cenipalma (Palmar de la Sierra) and two leading producers in the area. The study showcases different types of efficient irrigation systems, fertigation and water harvesting techniques through a small-scale demonstration project. A combination of convincing arguments, a viable business case and an on-field application of fertigation use and sensors in efficient irrigation systems will increase the likeliness of moving away from conventional practices. These innovations in water and fertilizer management on a farm level could benefit both the environmental as well as the economic sustainability of palm oil production.PROJECT ACTIVITIES AND OUTCOMESThree main limiting factors for the adoption of efficient irrigation systems were found during this study: 1.	Theft of sprinklers 2.	Producers are reluctant to invest making use of credits 3.	Lack of knowledge on the costs of sprinkler and drip irrigation systems, especially the maintenance costs, and the time of returning the investment. Implementing efficient irrigation systems in the Sevilla basin can save up to 67% and 72% of water when adopting sprinkler or drip irrigation, respectively. The most suitable solution for improving irrigation application uniformity, crop yield and water productivity in the oil palm plantations in the basin was found to be sprinkler irrigation. But theft of sprinklers is the main limiting factor for producers to not adopt sprinkler irrigation. Theft of drippers does not occur, which increases the suitability of drip irrigation, even though the initial investment costs are higher. In the implementation phase, a pilot project was established at the experimental station of Cenipalma and at two leading producers. The project implemented (or improved the current) fertigation systems and compared different irrigation techniques (drip versus two types of sprinklers). Special attention is given to measuring devices (soil moisture and flow meters). Irrigation advice was provided using the irrigation tool of IrriWatch. Using satellite data, this tool calculates the evapotranspiration of the crop and the soil moisture content within the rootzone. By including the weather forecast, the tool formulates a soil moisture-based irrigation schedule for every part of a field. Producers can use this tailored irrigation schedule for deciding when, where, with what amount and at which frequency to irrigate. This enables producers to use water more efficiently and to boost production. Soil moisture content sensors were established in the field to validate the measurements of the tool. The pilot study showed that the field with surface irrigation had a lower soil moisture content and lower uniformity of soil moisture content throughout the dry season compared to the fields with sprinkler and drip irrigation, causing water stress which decreases biomass production, resulting in lower production of fruit bunches. The field with drip irrigation had a higher soil moisture content and higher uniformity of soil moisture content than the field with sprinkler irrigation, but the difference is smaller than the difference between sprinkler and drip irrigation compared to surface irrigation. The pilot trials with fertigation will continue after the project, as these results will only be seen three years after the intervention started. The lack of knowledge on the investment and maintenance costs and return of investment of sprinkler and drip irrigation was found to be one of the main limiting factors for adoption by producers. The cost-benefit analysis contributed to bridging this gap. Investing in drip irrigation is the most profitable option as calculated in this report. Sprinkler is also profitable, but under climate change conditions less attractive. Surface irrigation is not worthwhile, only if producers pay no or a reduced fee for their water use. Fertigation is shown to be cost-effective. An extra advantage is that you can make use of the efficient irrigation systems (drip, sprinkler) throughout the whole year. However, more research and trials need to be done at Palmar de la Sierra, for tailoring the approach and to showcase it to producers. The future action plan includes four pillars. The first is continuing knowledge development on the use of efficient irrigation systems. Cenipalma will keep monitoring the pilot studies that were established as part of this project. Moreover, the Palmar de la Sierra experimental station of Cenipalma is fully committed to the topic of efficient water use. Cenipalma will prosecute the research projects that are already running at this experimental station. The gained knowledge and experience are disseminated within the second pillar. The results of the pilot studies are used to quantify the benefits of efficient irrigation systems and to stimulate adoption by producers. Next to that, Cenipalma will support producers which want to implement efficient irrigation systems with technical assistance. In order to have sustainable water management in the basin as a whole, a holistic approach should be taken, which is the third pillar. Multiple actors and users of water in the basin recognize the urgency to enhance efficient use of water. Connecting strategies between the basin authority Corpamag, the irrigation district Asosevilla and the productive sectors of coffee, banana and palm oil, including the engagement of the sector organisations will be the strategy for contributing to a shared vision on the basin. When implementing efficient irrigation systems within the whole basin an implementation strategy should be defined together with Corpamag and Asosevilla, to avoid water scarce situations due to reductions of drainage flows upstream. The fourth pillar includes connecting with the local and national government, and banks, in order to tackle two of the main limiting factors: the high initial investments of efficient irrigation systems and the short payback period of loans.