Comparative Study of Crop and Water Productivity Under Drip and Furrow Irrigation Systems for Plastic Tunnel-Grown Off-Season Vegetables

This study evaluates crop and water productivity of drip and furrow irrigation systems for off-season vegetables under plastic tunnels on farmer’s fields. Drip and furrow irrigation systems were tested on capsicum, cucumber and hot papers in this study. A permanent tunnel of 60 × 3 × 2 m was erected. Each crop was planted on 0.8 × 0.4 m raised beds under drip and furrow irrigation systems. Water productivity was calculated as the ratio of total yield to total water consumed by the crop. Data collected for three off-season vegetables revealed that each crop consumed less water under drip irrigation as compared to the furrow irrigation system. Among crops, hot peppers consumed the least amount of water irrespective of irrigation systems in comparison to furrow irrigation system. In addition, the percent use of all inputs under drip irrigation was reduced: water by 30%-45%, fertilizers by 22%-30% and pesticides by 15%-20% (because of reduced temperature and humidity) for different crops. In comparison to furrow irrigation, yield under drip irrigation was increased by 20%-30% and net farm income by 19%-41% for different crops. Average water productivity (kg/m3) was increased by 141% for capsicum, 165% for cucumber and 109% for hot papers under drip irrigation system compared to the furrow irrigation system. In conclusion, drip irrigation technology is effective in improving crop growth and water productivity, and reducing water scarcity while considerably reducing fertilizer and pesticide use. These results advocate for drip irrigation as an ideal technology to address the issue of freshwater resource scarcity in Pakistan.