Interactive Effects of Mycorrhizal Inoculation and Organic Soil Amendments on Nitrogen Acquisition and Growth of Highbush Blueberry

Abstract

<jats:p>The ability of mycorrhizal and nonmycorrhizal `Elliott' highbush blueberry (<jats:italic>Vaccinium corymbosum</jats:italic> L.) plants to acquire soil N under different preplant organic soil amendment regimes (forest litter, rotted sawdust, or no amendment) was investigated in a field experiment using <jats:sup>15</jats:sup>N labeled (NH<jats:sub>4</jats:sub>)<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub>. Plants inoculated with an ericoid mycorrhizal isolate, <jats:italic>Oidiodendron maius</jats:italic> Dalpé (UAMH 9263), had lower leaf <jats:sup>15</jats:sup>N enrichment and higher leaf N contents than noninoculated plants but similar leaf N concentrations, indicating mycorrhizal plants absorbed more nonlabeled soil N than nonmycorrhizal plants. Mycorrhizal plants produced more plant dry weight (DW) and larger canopy volumes. The effect of preplant organic amendments on the growth of highbush blueberry plants was clearly demonstrated. Plants grown in soil amended with forest litter produced higher DW than those in either the rotted sawdust amendment or no amendment. Plants grown in soils amended preplant with sawdust, the current commercial recommendation, were the smallest. Differences in the carbon to nitrogen ratio were likely responsible for growth differences among plants treated with different soil amendments.</jats:p>

Cultural Variation and Mycorrhizal Status of Blueberry Plants in NW Oregon Commercial Production Fields

“…These higher concentrations are a result of the EMF enhancing uptake of inorganic N and P (Mitchell and Read, 1981;Stribley and Read, 1976) and organic or insoluble N and P compounds from the soil (Kerley and Read, 1995;Read et al, 1989;Stribley and Read, 1980). A study using 15 N-labeled ammonium in fumigated soil found that blueberry plants inoculated with ericoid mycorrhizal fungi had lower 15 N enrichment (Yang et al, 2002). This indicated that in mycorrhizal blueberry plants the 15 N label was diluted by uptake of alternative N sources.…”

“…These higher concentrations are a result of the fungus not only enhancing uptake of soluble inorganic N and P (Mitchell and Read, 1981;Stribley and Read, 1976) but also utilizing organic or insoluble N and P compounds in the soil (Kerley and Read, 1995;Read et al, 1989;Stribley and Read, 1980). When 15 N labeled ammonium is fed to mycorrhizal and non-mycorrhizal Vaccinium growing in sterile and fumigated soil, mycorrhizal plants have significantly greater yields and total nitrogen content than nonmycorrhizal plants; however mycorrhizal plants have lower 15 N enrichment (Stribley and Read, 1974a;Yang et al, 2002), indicating that the label is diluted by alternative N sources in mycorrhizal plants. In addition to an ability to readily use ammonium and nitrate, EMF can also use amino acids, peptides, proteins, and polymers such as chitin and lignin to transfer substantial quantities of N to the plant host (Bajwa and Read, 1985;Bajwa and Read 1985;Kerley and Read, 1995;Kerley and Read, 1997;Kerley and Read, 1998;Stribley and Read, 1980).…”

“…Under field conditions in the Northeastern U.S., mycorrhizal infection of cultivated blueberries is low (Boyer, 1982;Goulart et al, 1995;Yang et al, 1998;Powel and Bates, 1981), and inoculation of tissue cultured highbush blueberry can increase plant growth and root dry weight (Yang et al, 2002). Others have found that the colonization of blueberry varies significantly with the cultivar (Czesnik and Eynard, 1990;Eynard and Czesnik, 1989), rate of fertilizer application (Powell, 1982) and the amount and type of soil organic matter present in soil (Yang et al, 2002). Increased application of fertilizer can depress mycorrhizal infection levels in blueberry seedlings (Powell, 1982).…”

Frequency and Intensity of Root Colonization by Ericoid Mycorrhizal Fungi in Nursery Production of Blueberry Plants

“…Colonization of blueberry can vary significantly with cultivar (Czesnik and Eynard, 1990;Eynard and Czesnik, 1989), rate of fertilizer application (Powell, 1982) and the amount and type of soil organic matter present in the soil (Blasing, 1989;Czesnik and Eynard, 1990;Eynard and Czesnik, 1989;Haynes and Swift, 1985;Yang et al, 2002). A field study in Northeastern North America found that inoculation of tissue-cultured highbush blueberry increased plant growth and root dry weight (Yang et al, 2002). However, increased application of fertilizers can depress mycorrhizal infection levels in blueberry seedlings (Powell, 1982;Golldack et al, 2001).…”

Genotype‐specific effects of ericoid mycorrhizae on floral traits and reproduction in Vaccinium corymbosum

“…Cultivar (i.e., genotypes) specific effects of inoculation were found by others as well (Scagel, ; Scagel and Yang, ). Early‐blooming cultivars tended to have higher levels of colonization than later‐blooming ones (Scagel and Yang, ) and colonization altered the ways in which plants utilize nutrients (Powell and Bates, ; Yang et al., ; Scagel, ; Zinati et al., ). Even closely related genotypes showed a high degree of variability in response to inoculation.…”