SEASONAL DYNAMICS OF MINERAL UPTAKE AND ALLOCATION IN WHOLE PINOT NOIR VINES IN A RED-HILL SOIL

Authors: Schreiner, Roger - Paul; BAHAM, JOHN - OREGON STATE UNIVERSITY

Submitted to: Agricultural Experiment Station Oregon State University Progress Reports
Publication Type: Proceedings
Publication Acceptance Date: 2/1/2002
Publication Date: 3/1/2002
Citation: SEASONAL DYNAMICS OF MINERAL UPTAKE AND ALLOCATION IN WHOLE PINOT NOIR VINES IN A RED-HILL SOIL. Schreiner, R.P., Baham, J.

Interpretive Summary:

Technical Abstract: Whole vine mineral budgets were determined by destructively harvesting 21-yr-old Pinot noir vines growing in a red-hill soil in Oregon. All vine tissues including fine roots were collected and analyzed for concentrations and contents of N, P, K, Mg, Ca, Fe, Zn, Cu, B, and Mn. Canopy demand between sample dates was calculated from the change in combined mineral contents of the green canes, leaves & petioles, and fruit. Actual vine uptake from soil was determined from the change in total vine content between harvest dates. Uptake for most macro elements was very closely tied with canopy demand. N and P were taken up early in the season peaking near bloom, while peak K, Ca, and Mg uptake was extended closer to veraison. Uptake of microelements Fe, Mn, B, Zn, and Cu in whole vines could not be accurately determined from our data because their concentrations varied too much from vine to vine. Canopy demand for K was greater than any other macro element at 28 pounds per acre, and the vast majority of vine K came from soil uptake. Nitrogen was needed in second greatest quantity at 25 pounds per acre, but a very large proportion of N came from reserves. Calcium was needed in third greatest quantity at 22 pounds per acre and essentially all Ca came from uptake. Mg and P were needed in least quantity of macro elements at 7 and 3 pounds per acre, respectively, and were mostly taken up from soil. Approximately 11 pounds of K, 6 pounds of N, 1 pound of P & Ca, and a half-pound of Mg per acre were lost from the vineyard with the fruit. After harvest, about 8 pounds per acre of N was remobilized from leaves and petioles and stored in the trunk and roots before leaf fall. Nitrogen showed the largest dependence on stored reserves, both in supplying N to the developing canopy and in re-capturing N from leaves prior to leaf-fall. In addition, N was the only mineral to be taken up in significant quantity after harvest. Supply of P and Mg from stored reserves was also important, particularly before bloom when canopy demand exceeded uptake. Reserves of K and Ca were less important in supplying canopy needs. The most important reserve tissue for N and P was the large woody roots, followed by the trunk. The trunk was most important in supplying reserves of K and Mg, although fine roots also re-allocated significant K and P to the canopy. Changes in leaf versus petiole nutrient concentrations over the growing season showed very large differences for 8 out of 10 of the minerals examined. The choice of tissue type (leaf or petiole) and the best time to sample grapevines in Oregon for routine nutritional evaluation are clearly different for different minerals. Soil analysis showed that nitrate availability but not ammonia over the season was correlated to times of whole-vine N uptake, indicating that nitrate is the preferred nitrogen source for grapevines.