• Drip can replace micro-sprinkler in sweet cherry without compromising tree growth, yield, or fruit quality. • Drip irrigation increased soil moisture vs. micro-sprinklers, especially with amendments during hot periods. • A compost + bark chip mulch treatment with drip irrigation improved yield efficiency. • High-carbon bark chip mulch temporarily reduced early yield. • Drip irrigation amplified amendment benefits by conserving soil moisture and reducing N immobilization. Understanding how irrigation systems interact with orchard-floor amendments is critical for developing water-efficient, climate-resilient sweet cherry production. From 2014 to 2020, we conducted a split-plot field experiment in the Okanagan Valley, British Columbia, Canada, under a standardized nutrient program to evaluate irrigation method, drip versus micro-sprinklers, and soil treatments, control, fumigation, compost, shredded bark and wood-chip mulch, and compost plus mulch, on soil moisture dynamics, tree growth, and productivity. Drip irrigation maintained higher growing-season soil moisture on average and produced a clear irrigation by amendment interaction. Under micro-sprinklers, compost plus mulch tended to reduce measured soil moisture during hot periods, notably in 2017 and 2020, whereas under drip it generally increased soil moisture, and fumigation consistently resulted in the lowest soil moisture. Drip irrigation increased trunk cross-sectional area in most years, while amendment effects on growth were largely confined to early establishment years. Yield responses were season-dependent, with drip outperforming micro-sprinklers in the warmer, drier year 2017 and micro-sprinklers outperforming drip in the cooler, wetter year 2020, while cumulative yield did not differ among treatments because of strong interannual variability. Amendment effects on yield were most evident in re-application years 2016 and 2019, consistent with short-term pulse responses superimposed on longer-term soil effects. Yield efficiency showed a significant irrigation by amendment interaction, with compost plus mulch under drip among the top-performing combinations, particularly in 2017 and 2018. Overall, these results indicate that drip irrigation is a robust strategy to conserve soil water and sustain growth, and that pairing drip with compost plus mulch can enhance yield efficiency when amendment type and reapplication timing are managed to avoid short-term tradeoffs, supporting climate-adaptive orchard management and more efficient use of water and local organic residuals.
Sharifi et al. (Sun,) studied this question.