| 摘要: |
| 采用耕层红油土进行盆栽试验,在每千克土施0. 40 g N和0. 30 g P
2O5的基础上,种植小白菜(黑油菜)和菠菜(宁夏圆叶)。采样前10 d设置150, 200和250 g /kg 3个土壤水分等级,研究土壤水分对蔬菜生长和硝态氮累积的影响。结果表明,在土壤水分为200和250 g /kg时,菠菜的生长量比水分为250 g /kg时提高108. 7%和174. 8%,小白菜提高108. 9%和109. 9%;而菠菜的硝态氮含量却分别降低29. 7%和19. 4%,小白菜降低22. 5%和25. 0%; 2种蔬菜的硝酸还原酶活性亦明显降低。对蔬菜生长、硝态氮吸收及还原的分析表明,土壤水分增加不仅促进蔬菜生长,还促进硝态氮的吸收及向地上部分转移。但生长量和硝态氮吸收的增加并不同速,由于生长超前引起的植物体内养分释稀效应,是增加土壤水分蔬菜硝态氮含量降低的主要原因。 |
| 关键词: 土壤水分，蔬菜，硝态氮累积 |
| DOI： |
| 分类号:S152.7 |
| 基金项目:陕西省农业发展办公室和杨凌基金资助项目 |
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| The Influence of Soil Water on Nitrate Accumulation in Vegetable |
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| Abstract: |
| Pot experiments were carried out with a red-oil soil by using Chinese
cabbage and spinach as indicating crops, in order to study the influences of soil water on
nitrate accumulation in vegetables at a fertilization rate of 0. 40 g N and 0. 30 g P2O5 per
kg soil.The results obtained showed that the yields of the two vegetables increased more
significantly at the soil water contents of 200 g /kg and 250 g /kg than at that of
150 g /kg, an increase of 108. 7% and 174. 8% for cabbage, and 108. 9% and 109. 9% for
Chinese cabbage. In contrast, the nitrate-N contents of the two vegetables decreased obviously, being 29. 7% and 19. 4% for spinach, and 22. 5% and 25. 0% for Chinese cabbage.Also decreased the nitrate red uctase activities of the vegetables. Comparing the
vegetable growth and the nitrate-N absorption and reduction, it is found that high soil
water supply increased notonly the vegetable growth but also the nitrate absorption and
its translocation from roots up to the above-ground parts.However, both the biomass
and the nitrate increases were not in the same proportion.The dilution effects caused by
more increase of biomass than nitrate absorption were the major cause for the decrease
of nitrate-N contents athigh soil water supply. |
| Key words: soil water,vegetable,nitrate accumulation |
