Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2005
Publication Date: 4/1/2006
Citation: Schreiner, R.P., Scagel, C.F., Baham, J. 2006. Nutrient uptake and allocation in a mature Pinot Noir vineyard in Oregon,USA. HortScience.41:336-345.
Interpretive Summary: A two-year study of nutrient uptake and use in mature Pinot noir vines growing in Jory soil in Oregon showed that the timing of nutrient uptake from soil generally corresponded to the timing of nutrient demand by the developing canopy. However, about 50% of N and P were supplied to the canopy from stored reserves in the roots and trunk. About 15% of canopy K was supplied from stored reserves and less than 5% of Ca or Mg came from reserves. Vines relied more heavily on stored N, K, and particularly P to supply the canopy in the drier 2002 season. N and P were taken up from soil earlier in the season (peak uptake at bloom) than K, Ca, and Mg (peak uptake after bloom). About 1/2 of the N and P present in leaves at the time of fruit harvest was recycled back into the vines before leaf fall in both years. About 1/3 of leaf K was recycled prior to leaf fall in the dry year only, and none of the Ca or Mg was recycled from leaves. The nutrient requirements to produce a Pinot noir crop of 2.4 tons/acre were as follows: 35 pounds/acre of N & K, 3.5 pounds/acre of P, 22 pounds/acre of Ca, and 10 pounds/acre of Mg. However, since significant stores of N and P were supplied to the canopy, much less of these nutrients were actually taken up from soil during the growing season. A crop load of 2.4 tons/acre was better than 1.8 tons/acre on these mature vines because K was in oversupply at the lower crop load resulting in high juice pH. Our data suggest that K supply in this soil is sufficient, but P supply is marginal in this Pinot noir vineyard.
Technical Abstract: The nutrient uptake and allocation patterns for N, P, K, Ca, and Mg were determined in mature, field-grown, dryland grapevines (Vitis vinifera L. cv. Pinot Noir) grown in Oregon, USA in 2001 and 2002. Biomass, nutrient concentrations, and nutrient contents of all plant organs, including roots, were determined on 14 sampling dates over two years. There was no seasonal change in the standing biomass of primary roots (fine feeder roots), small woody (<4 mm diameter) or large woody (>4 mm diameter) roots in these mature vines. Trunk biomass also did not change during the two years, but all other vine organs showed significant seasonal changes in biomass. The rate of N uptake was greatest at the time of bloom, when remobilization from reserves was also high. N was also taken up by vines after leaf fall had occurred in 2001, but not in 2002, when an early frost occurred prior to soil moisture recovery by autumn rains. Uptake of N, K, and Ca from soil was similar between years, even though canopy demand for N and K was greater in 2002 (significantly larger crop load). P uptake from soil was lower in 2002 than in 2001, which was most likely due to the drier conditions in 2002. A greater quantity of canopy N, K, and especially P was supplied from stored reserves in the drier 2002 growing season. Approximately 50% of canopy requirements for N and P was remobilized from reserves in the trunk and roots by the time of fruit maturity in 2002. Only 15% of canopy K and less than 5% of canopy Ca or Mg came from stored reserves in 2002. Our findings indicate that non-irrigated grapevines grown in Oregon aquire nutrients from soil earlier in the growing season and have a greater reliance on stored reserves of N and P than reported in previous studies from other growing regions.