Irrigation management in poplar (Populus spp.) plantations: A review

Poplar (Populus spp.) is widely planted around the world and has been closely linked to human beings since ancient times due to its multiple beneficial utilizations both for the environment and society. As one of the fastest-growing tree species in temperate zones, the high growth rate of poplar is associated with its high waterdemand, which makes it vulnerable to water deficits. To maintain and improve the productivity and quality of poplar plantations, by alleviating the impact of soil water deficit on tree growth and health, irrigation has been long applied as an essential cultivation practice for poplar plantations around the world. However, both fundamentals for irrigation and technology innovations are limited by the lack of critical knowledge on the irrigation management practices in poplar plantations. In this work, data and information collected from questionnaires, literature, and a survey around the world, were used to investigate the current situation of irrigation management in poplar plantations. We present a summary of the currently applied irrigation regimes for poplars. Then, with the help of the literature and a global dataset of poplar growth compiled with data from 27 sites in five countries, we thoroughly analyzed and reviewed the main effects of irrigation on poplar plantations. Finally, the profitability of irrigation in poplar plantations is discussed. We conclude with some existing problems and future research directions for irrigation management of poplars. In addition to providing directions for the sustainable management of poplar plantations in global water-limited regions, this work also provides a reference for the water management in plantations of other tree species.