Abstract: Effects of foliar fertilizers with different acidities phosphorus (P) forms on P absorptions and root morphologies of peanut (Arachis hypogaea L.) were investigated in the present study. P foliar fertilization experiment was conducted under artificial climate chamber in the study. The P foliar fertilizers with pH 5, pH 7 and pH 9 were sprayed to study the changes in P absorption-allocation and root morphological characteristics on seedling stage of peanut. Results showed that P foliar fertilizer under pH 7 increased significantly the P concentrations in leaf and stem by 46.9% and 25.7%, respectively. The P concentrations in leaf and stem were also promoted under pH 9, but it was lower than pH 7. P foliar fertilizers with different pH changed P absorption-allocation rates in root-stem-leaf systems. High pH (7 or 9) significantly decreased the P absorption amount and rats in roots, whereas it promoted the P absorption amount and rate in stem and leaf of peanut. P foliar fertilizer with high pH restricted the growth of root (especially the root length and surface area under root diameter<1.0 mm, and volume under root diameter>0.5 mm), while root length, surface area and volume were decreased by 172.6 to316.0cm, 72.8 to 96.6 cm² and 3.1 to 3.5 cm³ per pot under pH 7 and pH 9 compared with pH 5. Therefore, spraying the neutral or alkaline P foliar fertilizer improved the P absorptions by aboveground parts of peanut seedling, while restricted the growths of root systems and decreased the needs of P by changing the root morphology. This study will provide a scientific basis for the high-efficiency use of P nutrient resources and rational fertilization for peanut.

Key words: foliar fertilizer, surface area, root volume, allocation, phosphorus forms

摘要： 为探究叶面肥酸碱度及磷形态变化对花生磷吸收和根系形态学特性的影响,在人工气候室内进行盆栽试验,以蒸馏水为对照,研究不同酸碱度(pH值 5、7和9)的叶面磷肥对花生苗期磷吸收分配及根系形态指标的影响.结果表明:中性(pH 值7)叶面磷肥显著增加了地上部茎和叶片中的磷浓度,比对照增加了46.9%和25.7%;碱性(pH值 9)叶面磷肥增加了叶片和茎中的磷浓度,但增加幅度显著低于中性叶面磷肥;而酸性(pH值 5)叶面磷肥叶片和茎中磷浓度与对照无显著差异.喷施不同酸碱度叶面磷肥改变了磷在根-茎-叶体系的吸收分配比例,高pH下,根对磷的吸收量及其比例显著下降,而茎、叶总磷吸收量及其比例增加.pH值 7和9的叶面磷肥幼苗根系总长度、总根表面和总根体积比pH值5的叶面磷肥分别降低了172.6~316.0 cm、72.8~96.6 cm²和3.1~3.5 cm³.因此,喷施中碱性叶面磷肥促进了苗期花生地上部对磷的吸收,也显著抑制了花生根系的生长,减少了根系通过形态变化对磷的吸收需求.本研究可为花生磷资源高效利用及合理施肥提供科学依据.

关键词: 叶面肥, 表面积, 根体积, 分配, 磷形态