Doing more with less: Strategic agricultural land retirement during drought improves environmental and social outcomes

Agricultural land retirement is an increasingly common phenomena in irrigated agricultural systems where limited surface water availability has resulted in overdrafted groundwater basins, idled farmland, and major policy changes. Yet, the environmental and economic impacts of agricultural land retirement depend, in part, on the extent, spatial distribution and former crop type of retired lands. Here we evaluate the potential environmental, economic and social opportunities and tradeoffs embedded in land retirement decisions. Using the 2011–2015 extended drought in Kern County, California as an example, we evaluate different retirement scenarios for costs (based on foregone, crop-specific revenue), water savings, habitat for biodiversity, farmworker jobs and landscape connectivity relative to what was actually idled. Our results illustrate that the water savings and habitat protection for biodiversity resulting from the realized fallowing in 2015 could have been achieved with less than ⅙ of the cost. Alternatively, optimizing land retirement for water savings or habitat at the same cost as in 2015 could have tripled the amount of water saved or habitat created. More strategically retiring lands improved social and ecological outcomes, though tradeoffs among objectives often remained. This study illustrates the large benefits potentially attainable through landscape-level planning among landowners and the influence of policy goals on ecological and social outcomes.