叶类蔬菜的硝态氮累积及成因研究  

The cause of nitrate accumulation in leafy vegetables

作　　者：王朝辉[1] 田霄鸿[1] 李生秀[1] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《生态学报》2001年第7期1136-1141,共6页Acta Ecologica Sinica

基　　金：国家重点基础研究专项经费资助( G1 9990 1 1 70 7);国家自然科学基金 ( 49890 330 ;39970 4 2 9;30 0 70 4 2 9);杨凌科技开发基金

摘　　要：在菜园土壤上进行的田间试验 ,用禾谷类作物冬小麦作比较 ,研究了菠菜、小白菜、大青菜和油菜等叶类蔬菜累积硝态氮的特点。结果表明 :硝态氮累积是一般旱作作物的共性 ,苗期更为明显 ,无论蔬菜还是冬小麦均有较高的硝态氮含量 ( 367.8～ 1 4 1 3.4 μg/ g) ;但随生育期后延 ,蔬菜的硝态氮含量波动升高 ,冬小麦波动降低。盆栽试验表明 ,施入土壤的氮肥是蔬菜硝态氮累积的主要来源 ;过量施用氮肥所导致的蔬菜硝态氮吸收与还原转化不平衡是产生累积的根本原因 ;Field and pot experiments were carried out to study nitrate accumulation in leafy vegetables.N application rates at 0,90,180,270kg N/hm 2 were used in the field experiments with Chinese cabbage(\%Brassica Chinensis var. Oleifera Makino et Nenoto),green cabbage(\%Brassica Chinensis \%L.),spinach(\%Spinacia oleracea\% L.)and repe(\%Brassica campestris\% L.)as vegetables,and winter wheat(\%Triticusp aestvum\% L.)as a comparison crop.and they were planted on a vegetable field.The N rates of 0,0.20,0.40,0.60 and 0.80g N/kg soil were adopted for the pot experiments,using Chinese cabbage,spinach and rape as indicators,and the pots were placed in agreenhouse.\;The field experiment results showed that the nitrate accumulation was a very common phenomenon for all crops in the experiments,especially at their seedling stages.The nitrate concentrations of the 4 leafy vegetable species ranged from 367.8 to 1413.4 μg/g,while those in winter wheat ranged from 730.1 to 807.4μg/g at the early stages.For comparison of species differences in nitrate accumulation,a mean value of different N rates were calculated for each crop.The data showed that the concentration in winter wheat was 16.4% lower than that in Chinese cabbage,14.6% lower than that in green cabbage and 39.9% lower than that in rape,while 59.2% higher than that in spinach.It is difficult to distinguish the crop more prone to accumulate nitrates between leafy vegetables and winter wheat at their early stage.However,with plant growth,the nitrate concentrations in the leafy vegetables increased,whereas those in winter wheat decreased in a fluctuating way.The average concentrations of the entire growing stage were significantly higher for the vegetables than those for wheat.It was 1069.3μg/g in Chinese cabbage,452.6μ/g in spinach,while only 338.7μg/g in winter wheat.Obviously,as a whole,the leafy vegetables had higher abilities to accumulate nitrate than winter wheat did.\;Pot experiments showed that application of N fertilizer increased the vegetable growth at lo

关 键 词：叶类蔬菜 硝态氮累积 成因 

分 类 号：Q945.13[生物学—植物学]