Isotope Bioscience Laboratory, Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium; Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
Plant Physiol Biochem. 2021 Aug;165:207-216. doi: 10.1016/j.plaphy.2021.05.019. Epub 2021 May 20.
Enhanced use efficiency of fertilizer nitrogen (N) is paramount for sustainable pear fruit production. Sufficient fruit N content is a major factor for pear fruit storage potential, but fertilizer N use efficiency in pear fruit trees is generally low. The objective of this work was to test a methodology to quantify N uptake, partitioning and leaching loss as influenced by different calcium nitrate (Ca(NO)) fertilizer timings. To this end, 10-year-old 'Conference' pear trees (Pyrus communis L.) were transplanted and grown in soil-filled pallet boxes subjected to different timing of fertilizer addition. A fraction of the calcium nitrate was labelled with N and applied one month before full bloom, during summer and post-harvest. By sampling newly formed biomass (i.e., leaves, fruit and flower buds), temporal dynamics in the N fraction derived from calcium nitrate fertilization were determined. Simultaneously NO leaching derived from calcium nitrate fertilization was quantified. Our data suggest that spring application of N was most efficiently partitioned to leaves, fruits and buds at the time of harvest with a mean percentage of calcium nitrate derived N (Ndff) of 9.2%, 20.4% and 18.6%, respectively. Summer application of calcium nitrate was far less efficient at the time of harvest with Ndff of 0.56%, 0.89% and 1.4%, respectively, and substantially higher NO leaching was observed compared to spring fertilization. Post-harvest application showed even higher levels of leaching. Applying a split fertilization scheme with 60 kg N ha evenly spread over spring, summer, and post-harvest, about 9, 15 and 30%, respectively, of the fertilizer N had leached out as NO at the end of the growing season. This experimental approach may offer potential for detailed N budget studies for various fruit tree studies.
提高肥料氮（N）的利用效率对可持续的梨树生产至关重要。充足的果实 N 含量是梨果实贮藏潜力的主要因素，但梨树对肥料 N 的利用效率通常较低。本研究的目的是测试一种方法，以量化不同硝酸钙（Ca(NO₃)₂）施肥时间对氮吸收、分配和淋失损失的影响。为此，将 10 年生的‘Conference’梨树（Pyrus communis L.）移栽到装满土壤的托盘箱中，并进行不同施肥时间的处理。一部分硝酸钙用 N 标记，在盛花期前 1 个月、夏季和收获后施用。通过对新形成的生物量（即叶片、果实和花芽）进行采样，确定了来自硝酸钙施肥的 N 部分的时间动态。同时，量化了来自硝酸钙施肥的 NO 淋失。我们的数据表明，春季施氮最有效地分配到叶片、果实和芽中，在收获时的平均硝酸钙衍生氮（Ndff）分别为 9.2%、20.4%和 18.6%。夏季施用硝酸钙在收获时效率要低得多，Ndff 分别为 0.56%、0.89%和 1.4%，与春季施肥相比，NO 淋失明显更高。收获后施氮的淋失水平更高。采用 60 kg N ha 的分施方案，均匀分布在春季、夏季和收获后，大约 9%、15%和 30%的肥料 N 在生长季结束时以 NO 的形式淋失。这种实验方法可能为各种果树研究的详细氮预算研究提供了潜力。
