Straightforward guidelines for deficit irrigation (DI) can help in increasing crop water productivity in agriculture. To elaborate such guidelines, crop models assist in assessing the conjunctive effect of different environmental stresses on crop yield. We use the AquaCrop model to simulate crop development for long series of historical climate data. Subsequently we carry out a frequency analysis on the simulated intermediate biomass levels at the start of the critical growth stage, during which irrigation will be applied. From the start of the critical growth stage onwards, we simulate dry weather conditions and derive optimal frequencies (time interval of a fixed net application depth) of irrigation to avoid drought stress during the sensitive growth stages and to guarantee maximum water productivity. By summarizing these results in easy readable charts, they become appropriate for policy, extension and farmer level use. We illustrate the procedure to derive DI schedules with an example of quinoa in Bolivia. If applied to other crops and regions, the presented methodology can be an illustrative decision support tool for sustainable agriculture based on DI.
Bibliographical noteFunding Information:
Research funded by a PhD grant of the Flemish Interuniversity Council (VLIR) and by the Research Fund K.U.Leuven for post-doctoral fellowships. The research was partly carried out in Bolivia in the frame of the VLIR Own Initiative Project QuinAgua, scientific collaboration between K.U.Leuven and the Universidad Mayor de San Andres.
- Crop water productivity
- Drought stress
- Soil water balance
- Supplemental irrigation
- Water use efficiency