The production of highbush blueberry (Vaccinium corymbosum L.) has been increasing rapidly in the United States from 22,932 to 37,816 ha from 2005 to 2012 (U.S. Highbush Blueberry Council, unpublished data), whereas certified organic production has increased from 194 ha in 2003 (Strik and Yarborough, 2005) and 790 ha in 2008 (USDA, 2010) to an estimated 1665 ha in 2011 (Strik, unpublished data). There has been relatively little research on whether a sustainable and profitable organic production system can be developed for northern highbush blueberry.
Highbush blueberry requires well-drained soil and is often planted on raised beds (Strik, 2007). Raised beds help prevent saturated soils, reduce compaction, improve internal drainage (Magdoff and Van Es, 2000), and reduce disease problems such as Phytophthora root rot (Bryla and Linderman, 2007). Planting on flat ground, on the other hand, is thought to increase soil moisture and reduce soil temperature during the fruiting season, which is beneficial to root growth in southern highbush blueberry (complex hybrids based largely on V. corymbosum and V. darrowi Camp.) (Spiers, 1995).
Weed management is also critical for economic production in blueberry (Pritts and Hancock, 1992; Strik et al., 1993). Pre-emergent and contact herbicides are commonly used in conventional production systems, but chemical options are limited in organic systems. Acetic acid (vinegar) at a concentration of 9% to 20% has been effective at controlling some weeds organically (Fausey, 2003; Young, 2004). Propane flaming is used to control smaller weeds but may damage the plants, especially during establishment (Granatstein and Mullinix, 2008). Organic mulches are commonly used in blueberry to help control weeds (Burkhard et al., 2009; Krewer et al., 2009; Sciarappa et al., 2008), improve blueberry plant growth and yield (Clark and Moore, 1991; Goulart et al., 1997; Karp et al., 2006; Kozinski, 2006; Krewer et al., 2009; Savage, 1942; White, 2006), root distribution through the soil profile (Spiers, 2000), and whip and shoot production (Kozinski, 2006; White, 2006). Douglas-fir (Pseudotsuga menziesii M.) sawdust is a common mulch used in blueberry production in the northwestern United States, but it is expensive (Julian et al., 2011a) and the high initial carbon (C) to N ratio immobilizes N applied from fertilizers (White, 2006). It is often more difficult and more expensive to compensate for N immobilization with organic fertilizer products.
Weed mat (perforated landscape fabric) is considered an inert mulch (Granatstein and Mullinix, 2008) and is approved for use as a weed barrier by the USDA National Organic Program (USDA-AMS-NOP, 2011). Weed mat has been widely used in orchards as a result of its effectiveness for weed control, although weeds can grow in the area cut for the planting hole, and removal by hand may be required in commercial crops (Runham et al., 2000). Sciarappa et al. (2008) reported almost complete control of weeds when using weed mat plus a mulch of coffee grinds around the planting area in organic blueberry production in New Jersey. However, soil temperature may increase under the weed mat and thereby reduce plant growth (Neilsen et al., 2003; Williamson et al., 2006). Magee and Spiers (1995) found that white-on-black polyethylene-based mulches produced greater plant growth and yield than black plastic or black woven fabric mulches in southern highbush cultivars as a result of decreased soil temperature under the more reflective mulches. In Georgia, rabbiteye blueberry (V. virgatum Ait.) established with organic mulches had similar yields to those with weed mat in the first 2 years of establishment but greater yield in Years 3 to 5 (Krewer et al., 2009).
Compost may provide many benefits to blueberry production. As compost decomposes, it releases ≈3% to 10% of total N as mineral N for several years after the initial application (Gale et al., 2006; Sikora and Szmidt, 2001). Burkhard et al. (2009) found greater growth and yield of highbush blueberry when using seafood compost and manure–sawdust compost. Municipal yard debris compost is readily available in many production regions and may be suitable for commercial blueberry production (Costello, 2011).
Highbush blueberry requires N fertilizer at a rate of ≈25 to 100 kg·ha−1 N per year for optimum growth and production (Bañados et al., 2012; Chandler and Mason, 1942; Eck, 1988; Griggs and Rollins, 1947; Hanson, 2006; Hart et al., 2006). Uptake of N fertilizer is most rapid from bloom to harvest (Bañados, 2006; Throop and Hanson, 1997) but continues through the remainder of the growing season (Bañados, 2006). In ‘Bluecrop’, fertilizing with ammonium sulfate (50 kg·ha−1 N) produced more growth and fruit production during the first 2 years after planting than unfertilized plants or rates of 100 or 150 kg·ha−1 N (Bañados et al., 2012). Nitrogen fertilization with different rates of ammonium sulfate also affected biomass accumulation and allocation (Bañados et al., 2012); however, the impact of organic fertilizers on blueberry growth and allocation has not been reported.
Organic blueberry farmers commonly use fertilizer products approved by the Organic Materials Review Institute, including fish emulsion or feather meal as sources of N. Fish emulsion is applied as a direct liquid application to the soil of the in-row area or is injected through the drip irrigation system. Feather meal, a granular product, has a very rapid N mineralization rate, converting 30% to 60% of its total N to mineral N in 14 d in moist soil with cumulative mineral N release of 65% to 75% of total N after 70 d (Gale et al., 2006). Fish fertilizer products also mineralize N rapidly after application to soil. Sullivan et al. (2010) reported equivalent N mineralization rates (58% to 64% of total N converted to mineral N in 28 d) for a variety of fish and feather meal fertilizers.
The objective of the present study was to evaluate the effects of using flat or raised planting beds, three different mulch types, and feather meal or fish emulsion fertilizer on plant growth and early production in a new organic planting of northern highbush blueberry.
BañadosM.P.2006Dry weight and 15N-nitrogen and partitioning growth and development of young and mature blueberry plants. PhD thesis Oregon State University. <http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/9649/Banados_Maria_P_2006.pdf?sequence=1>
BañadosM.P.StrikB.C.BrylaD.R.RighettiT.L.2012Response of highbush blueberry to nitrogen fertilizer during field establishment. I. Accumulation and allocation of fertilizer nitrogen and biomassHortScience47648655
BrylaD.R.GartungJ.L.StrikB.C.2011Evaluation of irrigation methods for highbush blueberry—I. Growth and water requirements of young plantsHortScience4695101
BrylaD.R.LindermanR.G.2007Implications of irrigation method and amount of water application on Phytophthora and Pythium infection and severity of root rot in highbush blueberryHortScience4214631467
BrylaD.R.StrikB.C.2007Effects of cultivar and plant spacing on the seasonal water requirements of highbush blueberryJ. Amer. Soc. Hort. Sci.132270277
BurkhardN.LynchD.PercivalD.SharifiM.2009Organic mulch impact on vegetation dynamics and productivity of highbush blueberry under organic productionHortScience44688696
ChandlerR.B.MasonE.C.1942The effect of mulches on soil moisture, soil temperature, and growth of blueberry plantsProc. Amer. Soc. Hort. Sci.40335337
CostelloR.C.2011Suitability of diverse composts as soil amendments for highbush blueberry (Vaccinium corymbosum L.). MS thesis Ore. St. Univ. Corvallis OR. <http://hdl.handle.net/1957/26590>
CoxJ.2009Comparison of plastic weedmat and woodchip mulch on low chill blueberry soil in New South Wales, AustraliaActa Hort.810475482
EckP.1988Blueberry science. Rutgers Univ. Press New Brunswick NJ. p. 135–169
GaleE.S.SullivanD.M.HemphillD.CoggerC.G.BaryA.I.MyhreE.A.2006Estimating plant-available nitrogen release from manures, composts, and specialty productsJ. Environ. Qual.3523212332
GoulartB.L.DemchakK.YangW.Q.1997Effect of cultural practices on field grown ‘Bluecrop’ highbush blueberries, with emphasis on mycorrhizal infection levelsActa Hort.446271278
GriggsW.H.RollinsH.A.1947The effect of planting treatment and soil management systems on the production of cultivated blueberriesProc. Amer. Soc. Hort. Sci.49213218
HartJ.StrikB.WhiteL.YangW.2006Nutrient management for blueberries in Oregon. Oregon State Univ. Ext. Ser. Pub. EM 8918
JulianJ.StrikB.YangW.2011aBlueberry economics: The costs of establishing and producing blueberries in the Willamette Valley Oregon. AEB 0022. <http://arec.oregonstate.edu/oaeb/files/pdf/AEB0022.pdf>
JulianJ.StrikB.PondE.YangW.2011bBlueberry economics: The costs of establishing and producing organic blueberries in the Willamette Valley Oregon. Oregon State Univ. Pub. AEB 0023. <http://arec.oregonstate.edu/oaeb/files/pdf/AEB0023.pdf>
JulianJ.W.StrikB.C.LarcoH.O.BrylaD.R.SullivanD.M.2012Cost of establishing organic northern highbush blueberry: Impacts of planting method, fertilization, and mulch typeHortScience47866873
KrewerG.TertulianoM.AndersenP.LiburdO.FonsahG.SerriH.MullinixB.2009Effect of mulches on the establishment of organically grown blueberries in GeorgiaActa Hort.810483488
LarcoH.O.2010Effect of planting method weed management and fertilizer on plant growth and yield of newly established organic highbush blueberries. MS thesis Oregon State Univ. Corvallis OR. <http://ir.library.oregonstate.edu/xmlui/handle/1957/18065>
MagdoffF.Van EsH.2000Building soils for better crops. Sustainable Agriculture Network for the Sustainable Agriculture Research and Education Program of the Cooperative State Research Education and Extension Service. 2nd Ed. p. 75 133
MageeJ.B.SpiersJ.M.1995Influence of mulching systems on yield and quality of southern highbush blueberries. In: Gough R.E. and R.F. Korcak (eds.). Blueberries: A century of research. Haworth Press Inc. Binghamton NY
NeilsenG.H.HogueE.J.ForgeT.NeilsenD.2003Mulches and biosolids affect vigor, yield, and leaf nutrition of fertigated high density appleHortScience384145
PliszkaK.ŚcibiszK.RojekH.1993The effect of soil, management and mineral fertilization upon growth and cropping of the highbush blueberry cv. ‘Bluecrop’Acta Hort.346149154
PrittsM.P.HancockJ.F.1985Lifetime biomass partitioning and yield component relationships in the highbush blueberry, Vaccinium corymbosum L. (Ericaceae)Amer. J. Bot.72446452
PrittsM.P.HancockJ.F.1992Highbush blueberry production guide. NRAES-55 Ithaca NY
RunhamS.R.TownS.J.FitzpatrickJ.C.2000Evaluation over four seasons of a paper mulch used for weed control in vegetablesActa Hort.513193201
SavageE.F.1942Growth responses of blueberries under clean cultivation and various kinds of mulch materialsProc. Amer. Soc. Hort. Sci.40335337
SciarappaW.PolavarapuS.BarryJ.OudemansP.EhlenfeldtM.PavlisG.PolkD.HoldcraftR.2008Developing an organic production system for highbush blueberryHortScience435157
SikoraL.J.SzmidtR.A.K.2001Nitrogen sources mineralization rates and nitrogen nutrition benefits to plants from composts p. 287–305. In: Stofella P.J. and B.A. Kahn (eds.). Compost utilization in horticultural cropping systems. CRC Press Boca Raton FL
SpiersJ.M.1986Root distribution of ‘Tifblue’ rabbiteye blueberry as influenced by irrigation, incorporated peatmoss, and mulchJ. Amer. Soc. Hort. Sci.111877880
SpiersJ.M.1995Substrate temperatures influence root and shoot growth of southern highbush and rabbiteye blueberriesHortScience3010291030
StrikB.2007Horticultural practices of growing highbush blueberries in the ever-expanding U.S. and global sceneJ. Amer. Pomol. Soc.61148150
StrikB.BrunC.AhmedullahM.AntonelliA.AskamL.BarneyD.BristowP.FisherG.HartJ.HavensD.InghamR.HaufmanD.PenhallegonR.PsheidtJ.ScheerB.ShanksC.WilliamsR.1993Highbush blueberry production. Pacific Northwest Extension Bulletin 215. Oregon State University Corvallis OR
StrikB.BullerG.2005The impact of early cropping on subsequent growth and yield of highbush blueberry in the establishment years at two planting densities is cultivar dependentHortScience4019982001
SullivanD.M.AndrewsN.LunaJ.M.McQueenJ.P.G.2010Estimating N contribution from organic fertilizers and cover crop residues using online calculators p. 83–86. In: Proc. 2010 19th World Congress of Soil Science Soil Solutions for a Changing World 1–6 Aug. 2010 Brisbane Australia. <http://www.iuss.org/19th%20WCSS/Symposium/pdf/D3.2.pdf>
USDA2010Organic production survey (2008). Vol. 3. Special studies part 2. 2007 Census of Agr. Updated July 2010
USDA-AMS-NOP2011Program handbook: Guidance and instructions for accredited certifying agents & certified operations. Winter edition
Valenzuela-EstradaL.R.2008Above- and below-ground physiology in Vaccinium corymbosum L. (northern highbush blueberry) in response to water stress and reproductive effort. PhD thesis Pennsylvania State Univ. University Park PA
Valenzuela-EstradaL.R.RichardsJ.DiazA.EissensatD.2009Patterns of nocturnal dehydration in root tissues of Vaccinium corymbosum L. under severe drought conditionsJ. Expt. Bot.6012411247
WebberC.L.HarrisM.A.ShereflerJ.W.DurnovaM.ChristopherC.A.2005Vinegar as an organic burn-down herbicide p. 168–172. Proc. of the 24th annual Oklahoma and Arkansas horticulture industries show. Fort Smith AK
WhiteL.D.2006The effect of pr-plant incorporation with sawdust sawdust mulch and nitrogen fertilizer rate on soil properties and nitrogen uptake and growth of ‘Elliott’ highbush blueberry. MS thesis Oregon State Univ. Corvallis OR. <http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/1363/WholeThesis.pdf?sequence=1>
WilliamsonJ.KrewerG.PavlisG.MainlandC.M.2006Blueberry soil management nutrition and irrigation. In: Childers N.F. and P.M. Lyrene (eds.). Blueberries for growers gardeners and promoters. E.O. Gainesville FL
WuL.YuH.DongL.ZhuY.LiC.ZhangZ.LiY.2006Comparison of mulching treatments on growth and physiology of highbush blueberryActa Hort.715237240