Understanding and promoting adoption of irrigation efficiency practices in Paso Robles, California vineyards: The importance of farm typology and grower sustainability networks

Abstract

Groundwater depletion and water scarcity are significant global risks facing humanity. Improved irrigation efficiency is a key strategy for achieving sustainable management of groundwater resources. In 2021, we surveyed vineyard managers in the Paso Robles (California) American Viticultural Area, assessing the level of, and barriers to, adoption of six irrigation efficiency best management practices (BMPs). BMP adoption was relatively low overall, with the use of flow meters most widespread (55%) and plant tissue sampling to schedule irrigation least prevalent (32%). Financial expense to implement and manage was the most cited barrier and UC Cooperative Extension was the most trusted information source for water management concerns. There was a clear relationship between BMP adoption and the vineyard and vineyard manager characteristics included in the study. Participation in Sustainability in Practice (SIP) certification and its related grower-to-grower network activities emerged as the single most important determinant of BMP adoption. A vineyard typology of three types (small, medium and large-scale) was also constructed to understand the relationship between BMP adoption, vineyard type and other vineyard and vineyard manager characteristics. There were sharp differences between vineyard types in BMP adoption, barriers to adoption, and trusted information sources. The analysis concludes with targeted outreach recommendations to improve BMP adoption that include financial and technical assistance. Our approach of assessing adoption, characterizing barriers, identifying opportunities, and formulating an outreach strategy informed by farm typology is relevant to other irrigated agricultural regions facing water scarcity and groundwater depletion and could be extended to other irrigation BMPs as well as to other crops.