苗木晚季施肥研究现状与展望

Current Development and Prospect on Late-Season Fertilization to Tree Seedling

苗木的晚季施肥技术是以克服晚季养分稀释为目的,待苗木顶芽形成后进行的施肥措施。研究发现,晚季施肥可以有效克服养分稀释,提高苗木硬化水平和抗寒能力,促进苗木移栽后生根、苗木生长,提高养分吸收水平和造林成活率,并使移栽苗木提前发芽。前人对于晚季施肥的研究大多以氮素为主,有关晚季施入钾素对苗木抗寒性的影响存在争议,有关晚季施入其他元素的报道相对较少。大部分晚季施肥采用少次施肥,或每次添加相等养分的施肥方式。以稳态养分承载方式进行的晚季施肥被证明可以显著促进苗木晚季养分吸收。

Late-season fertilization（LSF）, which is developed for preventing nutrient dilution during seedling hardening, is usually performed after the establishment of seedling apical bud. It has been found that late-season nutrient dilution can be alleviated by LSF. Seedling hardening, new root growth, growth, nutrient uptake, and survival after planting could be enhanced by LSF. Also, bud break might be advanced as well. However, most previous reports on LSF focused on fertilizer of nitrogen, whereas the effect of potassium on seedling cold hardiness is inconclusive, and other nutrient elements used as LSF are even much less reported. Usually LSF is applied for quite limited times, or at a constant rate. LSF, with a steady-state nutrient loading has been proven to significantly improve nutrient uptake during hardening.