Distribution and Translocation of Nitrogen Absorbed During Late Spring by Two-Year-Old Grapevines Grown in Sand Culture

Abstract

Distribution and translocation of spring-applied nitrogen (N) were quantified for two-year-old Chenin blanc grapevines grown in sand culture. Vines were labeled with 15N over a four-week period stretching from the end of bloom to the end of rapid shoot growth. From this stage onwards, vines were fed unlabeled KNO 3, and entire vines were sampled eight times over a period of 11 months. Five samples were taken in the second and three during the third growing season. At the first sampling date (one week after the end of labeling), 55% of the labeled N was found in the vegetative growth, 20% in the bunches, and 25% in the permanent structure. Up to harvest, the total N content of shoots and leaves did not decrease, but the amount of labeled N showed losses of 48% and 21%, respectively. This indicated the importance of these organs as transitional reservoirs for N absorbed during late spring. Spring-applied N was also translocated from the permanent structure, resulting in the bunches containing 45% of the labeled N at harvest. Nearly 40% of the spring-applied N still present in the leaves at harvest was translocated to the shoots and the permanent structure during leaf senescence. At the end of dormancy, the fine roots, rootstock-and scion trunks contained similar concentrations of labeled N, but the rootstock trunk showed a larger proportion of soluble N. At the start of the third growing season, new growth utilized reserve N more readily from the permanent wood than from the roots, but roots played an important role at a later stage, i.e., during bloom. The annual turnover of N for the whole vine appeared to be in the order of 80%, which is considerably higher than that of some other deciduous crops.

Effects of Irrigation and N Fertilization on 15N Fertilizer Utilization by Vitis vinifera L. Cabernet Sauvignon in China

“…Another study reported that N application during budbreak and the post-harvesting period resulted in the highest content of labeled N in the dormant storage tissue and in the leaf tissue during rapid spring growth and at flowering [18]. A previous 15 N tracer test showed that 15 N urea could be transported to the fine roots at 12-24 h after absorption [19]. In the aforementioned study, both total N and fertilizer N were stored in the roots, especially in the coarse roots, and the growth and development of new organs after germination preferentially utilized the fertilizer N absorbed by the leaves.…”

“…Fertilizer absorption and utilization have been shown to be dependent upon irrigation techniques [8,9], soil types [10], phenological stages [11], fertilizer amounts and fertilization application frequency [12,13], and fertilizer application methods [14] in grapevines. In terms of fertilizer absorption and utilization in grapevines, it has been reported that nearly 40% of the spring-applied N that is still present in the leaves at harvesting is translocated to the shoots and permanent structures during leaf senescence [15]. The N recovery efficiency (RE N ) of grapevines has been reported to be similar at budbreak (7.1%) and blooming (10.6%) [16].…”

“…One study showed that more than 80% of the fertilizer N was distributed in the roots and branches in the first year, while about 50% was distributed in the fruit in the second year, and with an increase in fertilizer application, the N utilization rate decreased [20]. The 15 N distribution rates and use efficiencies of various grapevine organs under different water and fertilizer applications were found to differ [21].…”

“…Grapevine is a tree with high N demand, and there are differences in the absorption and utilization characteristics of N in various organs at different growth stages. Studies have found that the utilization rate of N fertilizer applied to fruit trees with soil is low, while the 15 N utilization rate of multiple fertilization treatments was significantly higher than that of single fertilization treatment [28]. The absorption and utilization rate of 15 N decreases with the decrease in irrigation, and the amount of irrigation is inversely proportional to the 15 N residue in soil [28].…”

“…Studies have found that the utilization rate of N fertilizer applied to fruit trees with soil is low, while the 15 N utilization rate of multiple fertilization treatments was significantly higher than that of single fertilization treatment [28]. The absorption and utilization rate of 15 N decreases with the decrease in irrigation, and the amount of irrigation is inversely proportional to the 15 N residue in soil [28]. Studies have shown that late topdressing can promote the movement of fertilizer N to fruit, and starting N topdressing can improve the absorption and utilization of fertilizer N [29].…”