Costs of establishing northern highbush blueberry in organic systems: impacts of planting method, fertilization, and mulch type

Authors: JULIAN, JAMES - Oregon State University; STRIK, BERNADINE - Oregon State University; LARCO, HANDELL - Oregon State University; Bryla, David; SULLIVAN, DAN - Oregon State University

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/10/2012
Publication Date: 7/1/2012
Citation: Julian, J., Strik, B.C., Larco, H.O., Bryla, D.R., Sullivan, D.M. 2012. Costs of establishing northern highbush blueberry in organic systems: impacts of planting method, fertilization, and mulch type. HortScience. 47(7):866-873.

Interpretive Summary: Organic production of highbush blueberry is generally considered more profitable than conventional production in Oregon. The cost of production, however, is greatly impacted by yield, prices, and the types of production practices used. A study was done to evaluate the effects of different production practices, including flat and raised planting beds, three mulch types, sawdust, sawdust plus compost, and weed mat, and two different organic fertilizers, feather meal and fish emulsion on the initial establishment costs and returns for producing organic blueberries. Raised beds cost $300 more per acre than flat beds but increased yield by 63% and improved net returns by as much as $2,150/acre. Weed mat cost more than sawdust or sawdust plus compost mulch but increased yield and reduced labor costs for weed control. Both fertilizers were applied by hand and produced high yields, but fish emulsion was considerably more expensive, costing $2,050 more per acre than feather meal. When averaged over the first 3 years, the combination of raised beds, weed mat, and feather meal resulted in the lowest net cost to establish the planting.

Technical Abstract: A systems trial was established to evaluate factorial management practices for organic production of northern highbush blueberry. The practices include: flat and raised planting beds; feather meal and fish emulsion fertilizer applied at 29 and 57 kg/ha N; sawdust mulch, compost topped with sawdust mulch, or weed mat; and two cultivars, ‘Duke’ and ‘Liberty’. The planting was established in Oct. 2006 and was certified organic in 2008. Weeds were managed using organically approved products or methods, depending upon mulch treatment. Data were recorded on input costs and returns in year 0 (establishment year) through year 3. While planting on raised beds increased planting costs by $741 per ha, higher costs were more than offset by greater yields thus improving net returns by as much as $5,313 per ha compared to flat ground plantings. Cumulative net returns after three years ranged from -$32,692 to -$51,990 per ha when grown on raised beds, depending on cultivar, mulch, and fertilizer rate and source. The greatest yields were obtained in plants fertilized with the low rate of fish emulsion or the high rate of feather meal, but fertilizing with fish emulsion cost as much as $5,066 per ha more than feather meal. Higher costs of establishment and pruning for ‘Liberty’ compared to ‘Duke’ were offset by higher yields leading to improved net returns in all treatment combinations except feather meal fertilizer with weed mat or compost plus sawdust mulch. Mulch type affected establishment costs, weed presence, and weed management costs, which included product and labor for application of herbicides (acetic acid and lemon grass oil), as well as labor for hand pulling of weeds, depending on treatment. Our results indicate that choosing among the best yielding treatment combinations could improve net returns as much as $11,477 per ha. While the long-term effect of these treatments on economic returns is not yet known, it is clear that choice of production system has significant effects on returns in young organic blueberry production systems.