Characteristics of root growth in a fast-growing and high-yield poplar plantation under subsurface drip-irrigation

Abstract

The characteristics of root growth in the fast-growing and high-yield plantation of poplar I-214 (Populus × euramericana cv. ‘I-214’) were studied under two contrasting conditions, subsurface drip-irrigation (SDI) and normal irrigation (CK), on the sandy soil of Chaobai River, Beijing. The results showed that in the soil layer of 20–50 cm, there was a considerable increase in the amount of roots less than 10 mm in diameter (especially those of less than 2mm) under SDI, which was three times as much as that under CK. The absorbing roots under SDI were concentrated in the soil layer of 20–50 cm, while the roots under CK were distributed evenly in each layer. With respect to horizontal distribution, roots (d < 10 mm) under SDI were distributed mainly near the subsurface emitters and the amount of roots in 3 m in a row under SDI were 50% less than under CK. Therefore, it is suggested that subsurface emitters with the shape of “#” should be collocated in the middle of two rows and two individual trees to increase the distributing and absorbing range of roots under SDI, and further increase the plantation productivity.

Keywords

poplar, fast-growing and high-yield plantation / subsurface drip-irrigation / roots