355 REDUCING MECHANICAL IMPEDANCE OF ROOTS IN COMPACTED SOILS INCREASES ROOT AND SHOOT GROWTH

in HortScience
View More View Less
  • 1 Urban Horticulture Institute, Cornell University, 20 Plant Science Building, Ithaca, New York 14853

Four techniques for compaction amelioration were studied: 1) Vertical drainage panels; 2) vertical gravel-filled sump drains; 3) soil trenches filled with sandy loam; and 4) peat amended back fill. The control was backfilled with existing soil on the site. Vertical drainage mats and vertical gravel-filled sump drains were shown to increase O2% in surrounding soil; however, all O2 levels regardless of treatment were above what is considered limiting. Shoot and root growth of Pyrus calleryana `Redspire' was greatest for treatments that alleviated mechanical impedance (soil trenches and amended back fill) and least for treatments that did not (controls and vertical drains). Vertical drainage mats which alleviated mechanical impedance to a lesser degree showed intermediate growth.