钾镁水平对甘蔗主要矿质营养吸收和分配的影响

材料，采用盆栽沙培试验，在营养液不同钾水平（K1：0.10 mmol/L、K2：3.00  mmol/L、K3：6.00 mmol/L）和鎂水平（Mg1： 0.01 mmol/L、Mg2：0.50 mmol/L、Mg3：2.00 mmol/L）条件下进行培养，收获时测定甘蔗各组织部位的干物质量及氮、磷、钾和镁含量，分析植株矿质营养的吸收和分配特性。【结果】营养液钾、镁水平显著影响甘蔗植株叶片、茎和根中的氮、磷、钾和镁含量（P<0.05，下同），随钾、镁水平的升高，植株干物质量及氮、磷、钾吸收积累量显著增加，但K2与K3水平间、Mg2与Mg3水平间差异均不显著（P>0.05）。镁的吸收积累量随钾水平的升高而显著降低，随镁水平的升高而显著升高。钾、镁交互效应对甘蔗的茎干物质量、叶片磷吸收量和全株钾吸收量均有显著影响。较高的钾、镁水平可显著提高干物质及氮、磷、钾在甘蔗茎中的分配率，低钾水平则显著增加干物质在甘蔗根系中的分配。【结论】钾、镁水平及其交互效应可显著影响甘蔗养分的吸收、转运和分配。钾抑制镁向甘蔗地上部的转运，镁对钾的运输则无显著影响。在甘蔗生产中施钾肥的同时要重视镁素营养的补给。

关键词： 甘蔗;钾;镁;吸收;分配

中图分类号： S566.106.2                             文献标志码： A 文章编号：2095-1191（2019）08-1695-06

Effects of potassium and magnesium supply on main mineral nutrition absorption and distribution of sugarcane

HUANG Ying， ZHOU Wen-ling， CHEN Di-wen， SHEN Da-chun， FANG Jie-qun，

LING Qiu-ping， LU Ying-lin， JIANG Yong， AO Jun-hua*

（Guangdong Provincial Bioengineering Institute（Guangzhou Sugarcane Industry Research Institute）/

Guangdong Key Lab of Sugarcane Improvement & Biorefinery， Guangzhou  510316， China）

Abstract：【Objective】Effects of potassium and magnesium supply on main mineral nutrition absorption and distribution of sugarcane were studied to provide theoretical basis for the rational application of potassium and magnesium fertili-zers in sugarcane production. 【Method】A spot experiment with sand culture was conducted to analyze the dry matter and nitrogen（N），phosphorus（P），potassium（K），magnesium（Mg） contents in different organs of sugarcane variety Yuetang 09-13 and investigate the effects of potassium and magnesium interaction on absorption and distribution of N，P，K and Mg nutrients in sugarcane under different K levels（K1：0.10 mmol/L， K2：3.00 mmol/L and K3：6.00 mmol/L） and Mg levels（Mg1： 0.01 mmol/L， Mg2：0.50 mmol/L and Mg3：2.00 mmol/L）. 【Result】The supply levels of K and Mg had significant influence on the N，P，K and Mg content in leaves， stems and roots of sugarcane（P<0.05， the same below）. With increases of K and Mg level in the nutrient solution，the dry matter and the uptake of N，P，K in plant were significantly raised，but there was no significant difference between K2 and  K3 levels  and between  Mg2 and  Mg3 levels（P>0.05）. The absorption of Mg decreased significantly with the increase of K level and increased significantly with the increase of Mg level. The interaction effect of K and Mg（K×Mg） had significantly affected dry matter，phosphorus uptake in leaves and potassium uptake in total plant. Higher K and Mg levels significantly increased the distribution of dry matter and N，P and K in stems，while lower K levels significantly increased the distribution of dry matter in roots. 【Conclusion】K and Mg levels and their interaction can affect nutrient uptake， transport and distribution of total plant. K inhibits the transport of Mg from root to the shoot in sugarcane，while Mg has no effect on the transport of K. It is necessary to pay attention to the supply of Mg nutrition while applying K in sugarcane production .