Urban Agriculture and Small Farm Water Use: Case Studies and Trends from Cache Valley, Utah

The landscape of water in Utah is changing due to population growth, conversion of agricultural land to urban development, and increasing awareness of water scarcity. At the same time, Utah is experiencing a growing number of urban and small farms, but knowledge of water use in this sector is limited. Better understanding of what occurs at the field level on urban and small farms can aid state water use estimates and conservation efforts, and assist farmers in moving towards wiser water management. For the 2015 growing season, we performed irrigation evaluations for 24 urban and small farms in Cache Valley, Utah and we explore the results through case studies and identify trends among gross irrigation depth and field variables including field size, irrigation method, application uniformity, and scheduling practices. Results show a great degree of heterogeneity in irrigation methods, equipment used, and management practices. The beneficial consumed fraction of irrigation water ranged from 0.06 to 1.0. Small fields had lower application uniformities and greater irrigation depths than large fields. Surface irrigated fields had higher irrigation depths than sprinkle and drip irrigated fields. Additionally, fields using a fixed irrigation schedule had higher depths than fields that were irrigated inconsistently due to other factors. The results show that urban and small farm irrigators need improved knowledge of proper irrigation management. Irrigators, university extension services, and state water authorities working in this sector need to recognize the link between proper management and total water use, and focus more efforts on improving management, specifically how to use 1) low-cost methods to measure flow rates, 2) simple irrigation scheduling tools, and 3) improve application uniformity