Evaluation of Rainwater Harvesting System and Supplemental Irrigation Effect on Yield and Yield Components in Barley

Abstract

Shortage of rain and water resources has become a major problem in arid and semi-arid areas. Development of rainwater harvesting systems can be effective in increasing semi-irrigated cultivation area and decreasing water shortages. The objective of this study was to investigate the effects of rainwater harvesting system and supplemental irrigation on yield and yield components in winter barley (Hordeum vulgare L. cv. Abidar), A field experiment was conducted in a semi-arid region at Research Field of Tarbiat Modares University during the 2011-12 growing season. The experiment was a split factorial in a randomized complete block design with three replications. Irrigation treatments including time, amount and type of water source at six levels (twice with water, twice with treated municipal wastewater (TMW), once with wa ter, once with TMW and without irrigation) as main plot and rainwater harvesting surface treatments at three levels (compacted soil, not compacted and natural surface) and the distance from the runoff surface at three levels (one-third of first, middle, and end cropped surface) are defined as sub-plots. The results indicated that twice supplemental irrigation increased significantly thousand seed weight, biological yield and grain yield by 23.4%, 59.7% and 41.8%, respectively, compared with non-irrigated plots. Compacted surface plots had significantly higher values of thousand seed weight, biological yield, grain yield and number of spikes/ m2 (6.7%, 20.1 %, 22.1 % and 11.4%, respectively) when compared with natural surface treatment. There was not significant effect of supplemental irrigation with TMW on yield and yield components.