养分管理对生菜生物量与硝酸盐含量影响

Effect of Nutrition Management on Aboveground Biomass,Underground Biomass and Nitrate Accumulation in Lettuce

【目的】为了研究养分管理对生菜生物量与硝酸盐含量影响。【方法】以滇池流域晋宁县上蒜乡田间试验的9个典型处理为基础,分析了生菜硝酸盐含量的变化,探索在不同施肥状况下,地上、地下部分生物量间的关系。【结果】试验结果表明,地上生物量在T5(N_(405)P_(120)K_(300))处理时达到最大,地上、地下生物量之比在9~17;硝酸盐含量除T7(N_(270)P_(60)K_(300))外,其余处理均超过3000 mg/kg,污染等级均为四级;在滇池流域生菜对氮施肥量需求不高,当氮施肥量为135 kg/hm^2,磷施肥量为120 kg/hm^2时,生菜地上生物量较高,且地上、地下生物量之比较大;无论任何处理生菜硝酸盐的含量都较高。【结论】说明当地土壤和灌溉水氮含量很高,应减少氮肥的施用;控制氮肥施用,合理进行氮磷配比,是提高蔬菜品质,控制滇池农业面源污染的重要途径。

【Objective 】The study aims to study the effects of nutrition management on aboveground biomass, undergroimd biomass and nitrate accumulation in lettuce, 【 Method】 Nitrate accumulation of lettuce and the relationship between above-biomass and below-biomass were inves-tigated in 9 typical field experiments in Shang Suan Village, Jin Ning County, Dian Chi Area.【 Result】 The max above-biomass appeared in T5 （ N4q 5 P12〇 K30 q ） and the ratio of above-biomass and below-biomass is from 9 to 17. The nitrate content were over 3000 mg/kg except T7 （N27〇 Pg〇 K30q ） , and all of their contamination levels were Lv. 4. Lettuce in Dian Chi Area didn51 demand too much N. The above-biomass was higher, and the ratio between above-biomass and below-biomass was bigger when the use of N was 13 kg/hm2 and P was 120 kg/hm2. No matter how many fertilization treated to the lettuce the content of nitrate was high.【 Conclusion】 It meant the N in irrigated water and soil was high, too. Less N should be applied to. It was a highly significant way to control the agriculture area-source pollution of Dian Chi and the quality of vegetable with N controlled, matched up with high usage of fertilizer.