Influence of boundary plantation of poplar (Populus deltoides M.) on soil-water use and water use efficiency of wheat

Study was undertaken to assess the water use, moisture extraction and water use efficiency (WUE) of irrigated wheat, when grown in association with bo undary plantation of poplar, at different distances (0-3, 3-6, 6-9, 9-12, 1 2-15 and > 15 m (control)) from poplar (Populus deltoides M.) tree line. Pr esence of 3-year old poplar plantation at the boundary of wheat field cause d 7.5% higher water use than control (plots having no effect of tree line) up to 3 m distance from tree line which further intensified up to 12.7% and extended up to 6 m distance with 4-year old plantation. Similarly, maximum moisture extraction, both laterally and vertically, observed near the tree line. Contrary to this, WUE of wheat was reduced by 4.6% between 0 and 3 m distance from tree line with 3-year old plantation, decline intensified fu rther to 18.6% with 4-year old plantation. However, wheat was benefited by boundary plantation of trees between 3 and 9 m distance from the base of th e tree line which resulted in increased WUE of the wheat crop up to 9%. (C) 2001 Elsevier Science B.V. All rights reserved.