硅对紫花苜蓿生长与土壤氮素吸收转化的影响

Effects of silicon on alfalfa growth and nitrogen absorption and transformation in soil

硅虽然不是植物生长发育所必需的营养元素,但是它在增强植物的光合作用、提高作物产量、促进植物对其他营养元素的吸收与利用、适当缓解因营养元素过多而引起的不良反应等方面都有积极的作用。为了研究硅肥对紫花苜蓿蓿(Medicago sativa)生长和吸收利用氮素的情况,连续2年,采用田间试验的方式对苜蓿的株高、叶色、干重以及与氮素的吸收和利用相关的3个指标(吸氮量、土壤全氮含量和土壤脲酶含量)进行了研究。结果表明:在试验期内,中高度的硅肥施用量对紫花苜蓿的株高、叶色、干重、吸氮量均有显著地促进作用,且显著增加了土壤的全氮含量和脲酶活性,对土壤中硝态氮的吸收和利用情况也优于不施或少施。结论认为施用硅肥对紫花苜蓿的生长以及吸收和利用土壤中盈余氮素的能力有明显地促进作用,综合产投比、环境影响等多种因素建议施用量为3.2 kg/667m^(2)(SiO_(2))(T3处理)。

Silicon is not an essential nutrient element in the process of plant growth and development,but for many crops it plays a positive role in enhancing photosynthesis,improving yield,promoting the absorption and utilization of other nutrient elements,and appropriately alleviating the adverse reactions caused by excessive nutrient elements.In order to study the effects of silicon fertilizer on alfalfa growth and the absorption and utilization of nitrogen,from 2020 to 2021 the field experiment was adopted and some indexes(such as the height,leaf color value and dry weight)and the other three ones related to the absorption and utilization of nitrogen were studied.During the test period,when the application amount of silicon fertilizer is medium(T3)or high(T4),the significant promotion effect can be found not only in the plant height,leaf color,dry weight,nitrogen uptake of alfalfa,but also in the total nitrogen content of soil and urease activity(P<0.05).And under these two treatments,the ability of alfalfa to absorb and use nitrogen is better than the treatments of less or no silicon fertilizer.The recommended application amount of silicon fertilizer is 3.2 kg/667m^(2)(SiO_(2))(T3)after comprehensive consideration of multiple factors such as the ratio of production to investment and the impact on the environment.