Current and legacy effects of precipitation treatments on growth and nutrition in contrasting crops

Abstract

Changing patterns of precipitation are causing moisture stress in ways that alters crop growth and nutrition. Moisture stress not only directly impacts plant physiology but also indirectly affects plant growth by altering soil conditions. While the direct effects of moisture stress on growth and physiology are well studied, outcomes are often examined only as a consequence of current water stress within a single growing season, without consideration of accumulated moisture-induced changes in soil properties that accrue over many seasons (legacy effects). Moreover, our understanding of the impacts of current and legacy effects on both crop growth and nutrition are lacking. To explore these connections, the infrastructure of the Boston Area Climate Experiment (BACE) was leveraged to examine the responses of kale (Brassica oleracea), oat (Avena sativa) and bean (Phaseolus vulgaris) to three levels of precipitation (ambient, 75 % of ambient, and 50 % of ambient) when grown in legacy soils obtained from 10 years of differential precipitation inputs (high, medium, or low water). Plant growth was measured weekly, and nutritional differences within the edible portions of each crop were assessed at the end of the season. We found that differences in current precipitation affects both growth and nutrients, while legacy effects more strongly affect bionutrient levels than plant growth.