Application of Variable-rate Irrigation Technology to Conserve Water and Improve Crop Productivity PDF Download

Author: Aghil Yari
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Languages : en
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Book Description
"Variable-rate irrigation (VRI) is an emerging technology to optimize water and energy consumption, increase crop yields, and minimize environmental impacts. The goals of this research project were to assess the performance of VRI, to investigate field spatial and temporal variability for delineating irrigation management zones, and to quantify the potential water and energy savings, and crop productivity benefits of VRI for two crop types in southern Alberta. The research included a four-year field experiment during the 2013 to 2016 growing seasons at the Alberta Irrigation Technology Centre (AITC) in southern Alberta, Canada. In the 2013 and 2014 growing seasons, the experimental site was seeded to Hard Red Spring (HRS) wheat, and during the 2015 and 2016 growing seasons, Russet Burbank potato was planted. In 2013 and 2014, the performance of a center pivot irrigation system (CPIS) retrofitted with a commercial VRI package was assessed. Overall, the uniformity of application both along the system's lateral and in the travel direction were above 90% for the majority of the trials under the different wind speeds and water application depths. Wind speeds greater than 3.3 m s-1 reduced application uniformity by 3.9%. The volumetric flow measurement of the system indicated that up to 34% water savings can be achieved with VRI versus non-VRI. Moreover, the average energy cost decreased by 18% with VRI during the 2013 and 2014 seasons due to non-application of water to areas such as ponds, roads, and non-cropped areas in the study site. In an effort to delineate irrigation management zones for VRI application, temporal and spatial variation of soil physical and chemical properties were assessed. A stepwise multivariate regression approach and a fuzzy C-mean clustering algorithm were used to identify optimum number of variables for management zone delineation. It was found that soil electrical conductivity (EC), pH, and field elevation were the best of 10 parameters for management zone delineation. The validity criteria identified that the three management zones were optimum for the study site. Statistical analyses showed that the delineated management zones were significantly different in terms of crop yields. In the 2014 growing season, the highest wheat yield (4.80 t ha-1) was produced within the management zone three where the EC value was low and elevation was high. The lowest wheat yield (2.22 t ha-1) was in the management zone one situated in the high EC and low elevation areas. The AquaCrop model was used to optimize crop productivity within the three management zones. Simulation of HRS wheat growth in the study area under the different irrigation scenarios indicated that the crop yield would be improved with optimum irrigation application and drainage management.The study also has investigated the potato productivity under VRI technology in 2015 and 2016 growing seasons. Three irrigation applications (high, normal, and low irrigation treatments) were applied to Russet Burbank potatoes. In 2015, higher water application in the experimental plots resulted in no significant improvement to potato yield. The harvest of tubers in normal irrigation plots proved to be more uniform in quality and size of tubers. In 2016, there were no significant differences among irrigation treatments for any of the yield and quality factors analyzed." --