Fine root dynamics, timing of the events, and their relationship with soil conditions are of major interest because the understanding of these phenomena will permit a better synchronicity between nutrients and plant uptake. The goal of this research is to study the effect of different soil conditions, generated from two ground floor management systems, on fine root dynamics of apple trees under organic protocol in Michigan. The research has been conducted at the Clarksville Horticultural Experimental Station (CHES) of Michigan State University (MSU), in the organically certified (by OCIA) orchard of “Pacific Gala” grafted on M9 NAKB 337, established in May 2000. The orchard floor management systems being studied are: 1) a mulch made of alfalfa hay on the tree rows, with a width of 1.8 m and 2) the “Swiss Sandwich System” (SSS) that consists in superficial tillage of two strips 80 cm wide at each side of the tree row, leaving a 40 cm strip in the middle (on the tree row, under the canopy) where volunteer vegetation is allowed to grow. Root dynamics are studied on four replicas of two trees per each of the two ground treatments (16 in total) in a block design. For each tree in the trial four clear butyrate minirhizotrons have been installed (64 in total) at a 45° angle facing the tree, in the summer of 2002. Root dynamics, measured through pictures taken with a Bartz Technology digital camera and analyzed with a new software under development at MSU. During the 2003 season differences between the two systems have been found depending on the parameter taken in consideration. Mulch had different root distribution compared to SSS. Mulch treatment showed shallower roots even if below 90 cm the two systems didn't show any difference.
Dario Stefanelli, Roberto J. Zoppolo and Ronald L. Perry
Dario Stefanelli and Ronald L. Perry
One of the main problems facing organic horticulture is orchard ground floor management. Several works report that ground floor management affects root architecture of fruit trees, changing the position and depth of the roots. The purpose of this work is to study the effects of orchard ground floor management systems (GFMS) in an apple orchard under organic protocol in Michigan. The research was conducted at the Clarksville Horticultural Experimental Station of Michigan State University, in the organically certified (by OCIA) orchard of `Pacific Gala' grafted on M9 NAKB 337, established in May 2000. The GFMS being studied are: 1) mulch (MU) made of alfalfa hay on the tree rows, with a width of 2 m; 2) “Swiss Sandwich System” (SSS) that consists in superficial tillage of two strips 90 cm wide at each side of the tree row, leaving a 40-cm strip in the middle (under the canopy) where volunteer vegetation is allowed to grow; 3) flaming (FL) of the weeds in a 2-m strip underneath the tree canopy by a propane burner. Root architecture was studied in Sept. 2005 through the frequency of roots by the profile wall method. Trenches (3.36-m long × 1.32-m deep) were dug in the soil 45 cm from the tree trunk. Two 158 cm × 130 cm metal grid frames divided by strings into a 28 cm × 22 cm grid were placed against the profile faces to facilitate the counting and mapping of the root distribution. The GFMS did affect the root distribution of the two classes of roots under study (<2 mm and >2mm). In the FL and MU treatments, roots were noticed to be superficial and their frequency was higher close to the tree. In SSS, root frequency was similar until 80 cm deep in the soil profile and they extended farther from the tree.
Nicole Burkhard, Derek Lynch, David Percival and Mehdi Sharifi
leaf tissue samples, which caused a reduction in leaf tissue N in nonweeded subplots, although complicated by amendment-ground floor management interactions. In apple orchards, competition with sod groundcover has consistently resulted in lower
Amaya Atucha, Ian A. Merwin and Michael G. Brown
-term orchard groundcover management systems affect soil microbial communities and apple replant disease severity Plant Soil 304 209 225 Stefanelli, D. Perry, R.L. 2006 Effect of ground floor management systems on root architecture of Pacific Gala on M.9 NAKB
Shengrui Yao, Ian A. Merwin and Michael G. Brown
spruce forests in Saskatchewan and Manitoba, Canada Tree Physiol. 17 577 587 Stefanelli, D. Perry, R.L. 2006 Effect of ground floor management systems on root architecture of Pacific Gala on M.9 NAKB 337 under organic management HortScience 41 997 Tierney
Kathleen Delate, Andrea McKern, Robert Turnbull, James T.S. Walker, Richard Volz, Allan White, Vincent Bus, Dave Rogers, Lyn Cole, Natalie How, Sarah Guernsey and Jason Johnston
. Perry, R. 2003 Ground floor management and rootstock selection for organic apple production Michigan State University East Lansing, MI 10 Jan. 2007 < http://www.newenglandvfc.org/sessions03/organicappleproduction/groundfloormanagementrootstockselectionorganicappleprod.pdf >.