Early Performance During the Establishment of An Organic Apple Orchard with Varied Ground Cover Management Treatments and Nutrient Sources

Orchard groundcover management and nutrition are significant issues challenging sustainable organic apple production. Because of the interaction between ground cover and nutrition, these management practices must be studied simultaneously.  Research was initiated in 2006 to study and develop effective organic fruit tree best management practices for the South, with focused emphasis on ground cover and nutrient management, as well as to develop economic production budgets to determine feasible production methods.  In March 2006 the University of Arkansas planted ‘Enterprise’/M.26 in a replicated orchard to examine the effects of three organic fertilizer treatments (control, composted poultry litter [PL] and commercial pelletized fertilizer [CF]) and four groundcover treatments (shredded paper [SP], wood chips [WC], green municipal compost [GC] and mow-blow [MB]), with the goal of developing organic management recommendations for southern environments. The effects of nutrient and ground cover treatment interactions on tree growth, canopy and root development, soil biological, chemical and physical characteristics, foliar nutrient content and weed density were evaluated. Significant differences have been determined among the organic production systems after five seasons of growth. WC and GC  increased tree size,  height, trunk cross-sectional area, and leaf development.  Late season foliar nutrition showed no difference among treatments and after five growing seasons all ground cover treatments and nutrient treatments had adequate and similar foliar nutrient contents, however foliar N was in the low range. WC and PL had greatest early season soil N and GC increased late season soil N. Ground covers of WC or GC provided for adequate growth for early cropping during the first 5 seasons, however, early yield has been suppressed by environmental factors. WC and GC had significantly greater cumulative fruit yields compared to SP and MB but fruit diameter and average fruit weight was not affected by treatment in the first 3 cropping seasons.