【作者】 杨志海；

【导师】 张杨珠；

【作者基本信息】 湖南农业大学 ， 土壤学， 2004， 硕士

【摘要】 于2002年冬季及2003年夏季通过田间小区试验，研究了有机肥和无机肥不同比例配合施用对叶菜类蔬菜硝酸盐、亚硝酸盐含量、硝酸还原酶活性、Vc含量及土壤N0₃^-含量的影响。供试土壤为第四纪红土发育的红菜园土和河流沉积物发育的冲积菜园土，供试作物品种为小白菜。所得结果如下： 1．有机肥和无机肥配合施用均能不同程度地降低小白菜硝酸盐含量，其中以1：1·比例配施的效果最好，小白菜的产量较高，而硝酸盐含量较低。在2002年冬季，农大基地试验氮肥施用量为300kg·hm^-2，收获时以1/2M处理（有机肥和无机肥按1：1比例配施的处理）小白菜产量较高，而硝酸盐含量最低。在2003年氮肥施用量为180 kg·hm^-2的条件下，农大基地和东湖试验田小白菜以1/2M处理硝酸盐含量较低，产量较高。两年的试验结果均表明，有机肥和无机肥配施比例与小白菜的Vc含量和硝酸还原酶活性间无确定的关系。 2．土壤中硝酸盐含量随着有机肥和无机肥配施比例的不同而变化。在小白菜生长前期，在两种供试土壤条件下土壤硝酸盐含量都随着化肥施用比例的增加而增加。但在小白菜生长后期，两块试验田土壤硝酸盐含量随着有机肥和无机肥配施比例的不同而不同。在农大基地，土壤硝酸盐含量随着有机肥施用比例的增加而增加，而在东湖试验田的红菜园土条件下，CF处理（单施化肥的处理）的土壤硝酸盐含量在收获时最高。在整个生育期，由于两块试验田的土壤类型不同，土壤硝酸盐含量的变化表现各异。农大基地的冲积菜园土，土壤硝酸盐含量先增加，后下降，东湖红菜园土，土壤中硝酸盐含量直到收获时还在增加。 3．在小白菜生长前期，其植株体内的硝酸盐含量与土壤硝酸盐含量存在一定的相关性，在生长后期相关性很小。后期小白菜硝酸盐含量受前期土壤硝酸盐含量高低的影响。更多还原

【Abstract】 The effects of combined application of organic manure and chemical fertilizer on the nitrate , nitrite contents , the activity of nitrate reductase and the content of Vc in vegetable, and die content of nitrate in soil was studied by plot experiment in the winter of 2002 and the summer of 2003 .The soils used in experiments are red vegetable soil derived from quaternary red clay(the Donghu experimental site) and alluvial vegetable soil derived from alluvial deposit (HAU experimental site), and the crop used in experiments was pakchoi. The results are summarized as follows:1. the experiment result in 2002 and 2003 showed that when the ratio of combined application of organic manure and chemical fertilizer was 1:1 the nitrate content in pakchoi was lower and the yield of pakchoi was higher. The yield of 1/2M treatment (the treatment that the ratio of the combined application of organic manure and chemical fertilizer was 1 :l)was the highest and the nitrate content was lowest in 2002 when the amount of N fertilizer was 300kg.hm-2 .When the amount of N fertilizer was 180 kg.hm-2, the yield of the 1/2M treatment at Donghu experimental site and the CF treatment at HAU experimental site was higher and the nitrate content was lower. In the two year’s experiment, the variation of the Vc content and the activity of nitrate reductase was uncertain.2.The nitrate content in soil varied with the ratio of combined application of organic manure and chemical fertilizer. At the early growth stage, the nitrate content in soil increased with the ratio of chemical fertilizer increasing at HAU experimental site and Donghu experimental site, but at later growth stage, the variation of the nitrate content in soil is different with the ratio of organic manure applied in soils at the two experimental site. The nitrate content in soil increased with the increasing ratio of organic manure at HAU experimental site, but it was highest in soil with the CF treatment (the treatment that only chemical fertilizer was applied ) at Donghu experimental site. At the growth stage, the variation of the nitrate content in soil at the two experiment sites was different. The nitrate content in soil increased at the earlystage and decreased at the later stage at HAU experimental site, but af Donghu experimental site it was increased until harvest.3.There is closely positive relation between the nitrate contents in soil and in pakchoi, especially in the early growth stage. At the later growth stage, the relation between the nitrate content in pakchoi and in soil becomes insignificant. It was because that the nitrate content in pakchoi at the later growth stage was mainly affected by the nitrate content in soil at the early growth stage.更多还原