几种绿肥的根系分泌物对土壤锌的活化效应  

Zinc mobilization effect by root exudates of different green manure

作　　者：李欣雨 刘函亦 薛少琪 邢莉彬 彭亚茹 蒙元永 杨瑜 黄冬琳[1] LI Xin-yu;LIU Han-yi;XUE Shao-qi;XING Li-bin;PENG Ya-ru;MENG Yuan-yong;YANG Yu;HUANG Dong-lin(College of Natural Resources and Environment,Northwest A&F University/Key Laboratory of Plant Nutrition and Agro-environment in Northwest China,Ministry of Agriculture and Rural Affairs,Yangling Shaanxi 712100)

机构地区：[1]西北农林科技大学资源环境学院/农业农村部西北植物营养与农业环境重点实验室,陕西杨凌712100

出　　处：《中国土壤与肥料》2022年第1期81-89,共9页Soil and Fertilizer Sciences in China

基　　金：中央高校基本科研业务经费(2452020163);国家重点基础研究发展计划(2018YFD0200404-02)。

摘　　要：由于北方石灰性土壤锌有效性低,作物锌含量无法满足人体营养需求。前期研究发现种植绿肥可提高后茬小麦锌含量且后者与自身吸锌量正相关,但机制尚不明确。通过田间试验测定绿肥(黑麦豆、绿豆、高丹草)地上部锌含量,水培试验收集分析绿肥根系分泌物组成,土壤浸提试验测定根系分泌有机酸对土壤pH值及土壤锌的影响,从而揭示绿肥吸锌能力及其根系分泌物对土壤锌的活化效应。结果表明,不同种类及供锌水平绿肥根系分泌物存在差异,显著影响其吸锌能力。黑麦豆根系总有机酸和溶解性有机碳分泌量最高,其地上部锌含量最高;+Zn处理绿肥根系分泌量及地上部锌含量均高于Zn0处理。根系分泌的有机酸中草酸最高,其次为琥珀酸和柠檬酸,富马酸较低,其均能降低土壤pH值和增加土壤浸提液Zn;含量,以草酸作用最强。相比其他两种绿肥,黑麦豆根系分泌的总有机酸最高,分泌的主要是草酸和柠檬酸,这可能是其活化土壤有效锌、吸收锌能力强的重要机制。Due to the Zn bioavailability is low in northern calcareous soil,the Zn content of crops couldn’t meet the nutritional needs of humans.Previous field experiment showed that different green manures increased the afterculture wheat grain Zn content differently,and the wheat grain Zn content were positively correlated with green manure shoot Zn content.However,why green manure took up Zn differently and the soil Zn mobilization mechanism were still unclear.Field study,hydroponic culture and soil Zn extraction experiments were carried out to investigate the Zn content of green manure(black kidney bean,mung bean,sorghum×sudan Grass),and the main components of their root extrudates and the effect on soil pH and extractable Zn;by main low molecular organic acid of root extrudates,with the purpose of unveiling differences in Zn uptake by different green manures and the soil Zn mobilizing mechanism of green manures.Results showed the total dissolved organic carbon,total low-molecular weight organic acid and the main components of the root extrudates of green manures were significantly different from each other,affecting the concentration of Zn in the shoot of green manure.The root secretion ability of black kidney bean was stronger than other two kinds of green manures,the total organic acid and dissolved organic carbon were both the highest among three different green manures and also black kidney bean had the highest shoot Zn content.With Zn application,green manure secreted higher amount of organic acid than those without Zinc application,resulting that the Zn content of green manure with Zn supply were higher than those of green manure without Zn supply.All four main organic acids could significantly decrease soil pH and increase soil soluble Zn;.Among all the low molecular weight organic acids of root extrudates,oxalic acid secretion was the highest,followed by succinic acid and citric acid,and fumaric acid was lowest,and oxalic acid had the strongest effect.Compared with the mung bean and the sorghum×sudan grass

关 键 词：绿肥 根系分泌物 有机酸 土壤有效锌 活化效应 

分 类 号：S142[农业科学—肥料学]