Articles
Do northern highbush blueberries respond differently to humic and fulvic acids depending on mulching practices?
Article number
1440_63
Pages
463 – 468
Language
English
Abstract
A long-term research trial on organic northern highbush blueberry has been conducted in western Oregon, USA since 2006. Treatments from 2007 to 2016 were flat or raised planting beds, low or high fertilizer rates (up to 73 and 140 kg ha‑1 N) of feather meal or fish solubles, and three different mulches (sawdust, yard-debris compost topped with sawdust, or black woven polyethylene ground cover (weed mat)) in ‘Duke’ and ‘Liberty’. In 2017, existing weed mat was replaced and added over all plots, and soy-protein fertilizer containing N only was used thereafter in each plot.
Stopping compost use and fertilizing with soy fertilizer improved yield by up to 50% over the next 4 years.
Adding weed mat over organic mulches also improved yield compared to weed mat over bare soil.
Recent objectives aim to 1) determine if the original treatments continued to affect yield, soil, and plant nutrient status, and 2) study potential interactions between humic substances and treatments from the original trial.
Thus, the use of soy fertilizer was continued from 2021 to 2023, and half of the plots in each of the previous treatments were fertigated annually with 2.4 and 0.8 kg ha‑1 of humic and fulvic acids, respectively.
The effects of previous fertilizer types and rates on yield and plant and soil nutrients dissipated since their last application in 2016 to the extent that it was unnecessary to consider interactions with humic substances.
The presence of organic mulches under weed mat continued to affect soil organic matter, nutrients, and yield, while cultivar had a greater effect on leaf and fruit nutrients compared to mulch or humic substances.
Overall, fertigating with humic and fulvic acids had a limited effect on fruit production or plant nutrition, and their interactions with mulch and resulting soil conditions were infrequent.
Stopping compost use and fertilizing with soy fertilizer improved yield by up to 50% over the next 4 years.
Adding weed mat over organic mulches also improved yield compared to weed mat over bare soil.
Recent objectives aim to 1) determine if the original treatments continued to affect yield, soil, and plant nutrient status, and 2) study potential interactions between humic substances and treatments from the original trial.
Thus, the use of soy fertilizer was continued from 2021 to 2023, and half of the plots in each of the previous treatments were fertigated annually with 2.4 and 0.8 kg ha‑1 of humic and fulvic acids, respectively.
The effects of previous fertilizer types and rates on yield and plant and soil nutrients dissipated since their last application in 2016 to the extent that it was unnecessary to consider interactions with humic substances.
The presence of organic mulches under weed mat continued to affect soil organic matter, nutrients, and yield, while cultivar had a greater effect on leaf and fruit nutrients compared to mulch or humic substances.
Overall, fertigating with humic and fulvic acids had a limited effect on fruit production or plant nutrition, and their interactions with mulch and resulting soil conditions were infrequent.
Publication
Authors
A.J. Davis, S.B. Lukas, B.C. Strik, D.R. Bryla
Keywords
humic substances, nutrient concentration, organic production, Vaccinium corymbosum, yield
Online Articles (74)