Author
CHENG, XIAOMEI - UC-SAREP | |
Baumgartner, Kendra |
Submitted to: Soil Ecology Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 4/1/2003 Publication Date: 5/12/2003 Citation: Cheng, X., Baumgartner, K. 2003. Root system distribution and arbuscular mycorrhizal colonization of grapevines in a california vineyard. Soil Ecology Meeting Abstracts. Interpretive Summary: Fine roots play important roles in grapevine water and nutrient uptake. Vineyard floor management practices, including cover cropping, likely affect grapevine fine root distribution. Knowledge of the effects of these practices on fine roots will aid in our ongoing efforts to determine how cover cropping can be used to enhance grapevine nutrition and to encourage populations of beneficial soil microbes. In November 2002, we conducted a preliminary study in a commercial winegrape vineyard in Napa, CA to quantify grapevine root system distribution in the soil profile in between vineyard rows, where cover crop Zorro fescue has been maintained since 1998. Three trenches (180 cm length 100 cm width 90 cm height) were excavated perpendicular to vineyard rows from one vine trunk to adjacent trunk. In each trench, nine consecutive soil monoliths were collected at each of four soil depths. Grapevine roots were extracted, washed and separated into fine roots (<2 mm) and coarse roots (>2 mm). Root biomass and arbuscular mycorrhizal colonization were examined. The biomass of both fine and coarse grapevine roots was significantly greater in the three lower soil depths than in the topsoil depth. Fine roots were found across the vineyard rows, but root biomass was lower in the center of the vineyard middles than in the area close to the vine trunk, especially in the topsoil depth. Mycorrhizal colonization was greater in the 0-40 cm than in the 40-80 cm soil depths, but did not differ with respect to the distance from either vine trunk. These results indicate that, in the vineyard we examined, grapevine and cover crop roots coexist in the middle between vineyard rows. This overlap could lead to positive interactions, such as development of a mycorrhizal network among grapevine and cover crop roots, or negative interactions, such as water and nutrient competition. Technical Abstract: Fine roots play important roles in grapevine water and nutrient uptake. Vineyard floor management practices, including cover cropping, likely affect grapevine fine root distribution. In November 2002, we conducted a study in a commercial winegrape vineyard in Napa, CA to quantify grapevine root system distribution in the soil profile in between vineyard rows, where a cover crop of Vulpia myuros var. hirsuta cv. 'Zorro' has been maintained since 1998. Three trenches (180 cm length 100 cm width 90 cm height) were excavated perpendicular to vineyard rows from one vine trunk to adjacent trunk. In each trench, nine consecutive soil monoliths (20 cm length 10 cm width 20 cm height) were collected at each of four soil depths. Grapevine roots were extracted, washed and separated into fine roots (<2 mm) and coarse roots (>2 mm). Root biomass, and arbuscular mycorrhizal colonization were compared with respect to soil depth and distance from the vine trunk. The biomass of both fine and coarse grapevine roots was significantly greater in the three lower soil depths than in the topsoil depth. Fine roots were found across the vineyard rows, but root biomass was lower in the center of the vineyard middles (approximately 90 cm from the base of the vine trunk) than in the area close to the vine trunk, especially in the topsoil depth. Mycorrhizal colonization was greater in the 0-40 cm than in the 40-80 cm soil depths, but did not differ with respect to the distance from either vine trunk. These results indicate that, in the vineyard we examined, grapevine and cover crop roots coexist in the middle between vineyard rows. This overlap could lead to positive interactions, such as development of a mycorrhizal network among grapevine and cover crop roots, or negative interactions, such as water and nutrient competition and excessive devigoration of grapevines. |