Water harvesting and micro-irrigation systems for sustainable crop production in arid zones

Abstract:

Arid-zone farmers face an uncomfortable paradox: when rain does fall, much of it runs off unused, yet crops wilt between storms because no storage captures that fleeting surplus. This research tested five water-harvesting structures (rooftop collection, farm ponds, check dams, micro-catchments and well-recharge pits) coupled with drip and furrow irrigation on wheat and tomato at two sites Hail and Jazan, Saudi Arabia over three cropping cycles (2021–2024). Drip-irrigated plots fed by harvested water used 38.4% less total water than furrow-irrigated plots drawing from the same sources, while producing comparable or higher yields. Water use efficiency (WUE) for tomato reached 14.2 kg m⁻³ under drip at the lowest application rate (120 mm season⁻¹), compared with 8.7 kg m⁻³ for furrow. Farm ponds contributed the largest share of harvested water (27.3% of total stored volume), followed by check dam runoff (22.1%). Soil moisture at 30 cm depth was 17–24% higher in drip plots than in furrow plots at mid-season. Economic analysis showed that the combined water-harvesting and drip system reached payback within 2.4 years. These results confirm that integrating low-cost water harvesting with micro-irrigation can sustain commercial crop production in zones receiving less than 100 mm annual rainfall.