Water Needs of the Ash-Leaved Maple (Acer negundo L.) at the Period over Three Years after Reclamation in Different Regions of Poland

The ash-leaved maple (Acer negundo L.) has low habitat requirements, which is why this species is often used in the reclamation of industrial areas. The development of the reclamation plantings depends on the optimal water soil conditions that can be controlled by watering treatments. However, the use of irrigation requires determining the water needs of the cultivated species. The objective of the study was to evaluate the water needs of the ash-leaved maple in the reclamation plantings, in the period of over three years after planting. The water needs of the ash-leaved maple were determined using the crop coefficients method. Potential evapotranspiration was calculated using the Blaney-Criddle’s formula that was modified for the Polish conditions by Żakowicz. The water needs of the ash-leaved maple were assessed for five agro-climatic regions of Poland, in the years 1981-2010. The water needs of the ash-leaved maple in the growing period (April-October) were the highest in the C-E (638 mm) and C-N-W (637 mm) regions, and the lowest in the N-E (598 mm) and S-E (601 mm) regions. In July, the highest water needs were noted in the C-N-W region (149 mm) and the lowest in the S-W region (129 mm). In the studied thirty-years period, there was a significant upward trend in the water needs of the ash-leaved maple both during the growing season (except for the C-N-W region) and in July, in all the considered regions.