Water Needs of Black Locust Robinia pseudoacacia L. in the First Three Years of Growing in the Reclamation Plantings in Poland

Abstract

Black locust, considered an ornamental plant, is often used in the soil reclamation process, because it enriches the soil with nitrogen. High seedling survival rate in the first stage of reclamation depends mainly on sufficient water conditions controlled by irrigation, which in turn requires determining the plant’s water needs. The aim of the research was the estimation of black locust water needs during the first three years of growing. Potential evapotranspiration, as the measure of the plant water needs, was calculated in the study. The formula of Blaney-Criddle, modified by Żakowicz for Polish conditions, by using the adjusted crop coefficients, was applied. The calculations were carried out for the growing period (April–October) during the thirty years period (1981–2010), for five agro-climatic regions of Poland. The results presented a rising tendency in the black locust water needs for all tested 30 years and in each considered region. The water needs during the growing season increased in each ten years period of the analyzed 30 years by 9.8 mm in the central-eastern and south-eastern regions, by 9.4 mm in the south-west region,by 8.3 mm in the north-east region and by 5.8 mm in the north-west region.