Articles
EFFECTS OF PINE-NEEDLE AND COMPOST MULCHES AND WEEDS ON NITROGEN DYNAMICS IN AN ORGANICALLY-MANAGED HIGHBUSH BLUEBERRY FIELD
Article number
873_27
Pages
253 – 260
Language
English
Abstract
Weed control is a major challenge for organic growers and nitrogen (N) fertility can be unpredictable when using organic amendments.
A project assessing the use of heavy application of various mulches (pine needles and diverse composts) for organically-managed highbush blueberry (HBB) and their impact on weed growth and N acquisition, HBB growth, leaf tissue N, berry yield and quality, and soil acidity, moisture, temperature, and mineral N dynamics was initiated in 2005. From this, results for soil mineral N dynamics and plant and weed N removal are presented and discussed.
The experiment was located in an established field of Duke HBB in the Annapolis Valley, Nova Scotia, Canada.
The design was a randomized split-plot consisting of five blocks, four fertility and mulch treatments [no amendment, pine-needle mulch (PN), manure-sawdust compost (MC) and seafood waste compost (SC)] as the main plots, and two levels of weed management (+/- hand-weeding) as the split plots.
Residual (carry-over) effects of mulches one year after application were also examined.
Results from the 2-yr study indicate that weeds were a significant competitor for soil mineral N, reducing soil N content by 71%. In addition, weed competition was shown to reduce HBB growth and fruit yield.
There was no evidence of net N immobilization despite high C/N ratios of the PN (72:1) and MC (48:1). Elevated soil mineral N levels were maintained for the longest period under SC, while PN did not increase mineral N above control levels.
Pine-needle mulch was found to be the best treatment for suppressing weed competition, although additional N nutrition is warranted.
A project assessing the use of heavy application of various mulches (pine needles and diverse composts) for organically-managed highbush blueberry (HBB) and their impact on weed growth and N acquisition, HBB growth, leaf tissue N, berry yield and quality, and soil acidity, moisture, temperature, and mineral N dynamics was initiated in 2005. From this, results for soil mineral N dynamics and plant and weed N removal are presented and discussed.
The experiment was located in an established field of Duke HBB in the Annapolis Valley, Nova Scotia, Canada.
The design was a randomized split-plot consisting of five blocks, four fertility and mulch treatments [no amendment, pine-needle mulch (PN), manure-sawdust compost (MC) and seafood waste compost (SC)] as the main plots, and two levels of weed management (+/- hand-weeding) as the split plots.
Residual (carry-over) effects of mulches one year after application were also examined.
Results from the 2-yr study indicate that weeds were a significant competitor for soil mineral N, reducing soil N content by 71%. In addition, weed competition was shown to reduce HBB growth and fruit yield.
There was no evidence of net N immobilization despite high C/N ratios of the PN (72:1) and MC (48:1). Elevated soil mineral N levels were maintained for the longest period under SC, while PN did not increase mineral N above control levels.
Pine-needle mulch was found to be the best treatment for suppressing weed competition, although additional N nutrition is warranted.
Publication
Authors
N. Burkhard, D. Lynch, D. Percival
Keywords
Vaccinium corymbosum L., organic production, nitrogen management, mulch, compost
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