不同氮肥水平对甜菜生理指标及产质量的影响

Effects of Different Nitrogen Fertilizer Levels on Physiology,Yield and Quality of Sugar Beet

甜菜是氮敏感作物,筛选合适的氮肥施用量,对研究甜菜生长与氮肥的内在联系尤为重要。本试验通过对不同甜菜品种进行不同氮水平处理(0、120、180 kg/hm^(2)),对甜菜块根产量、含糖率、叶绿素含量、可溶性蛋白含量等指标进行统计学和相关性分析,探索氮肥施用量对甜菜不同生长阶段的影响。结果表明,随施氮量的增加,叶绿素及可溶性蛋白含量显著提高,其中与N0(0 kg/hm^(2))相比,N180(180 kg/hm^(2))处理的甜菜可溶性蛋白含量平均增加了30%;叶片和根的氮含量呈现先增加后降低的趋势,但在同一时期叶片和根的氮含量随氮肥施用量增加而增加。甜菜体内硝酸还原酶活性与生长时间成反比,与氮素供应量成正比;在第一时期(7月6日),N180处理下硝酸还原酶活性比N0增加68%~91%。相关性分析发现不同甜菜品种的根产量与氮肥施用量呈显著正相关,与含糖率呈显著负相关;N120(120 kg/hm^(2))与N180处理下产糖量接近,此时氮肥施用量的增加对甜菜经济价值影响较小,推测甜菜适宜的氮肥施用量为120~180 kg/hm^(2)。本研究结果为甜菜氮肥的合理施用提供了理论依据。

Sugar beet is a nitrogen-sensitive crop.Selecting an appropriate amount of nitrogen fertilizer application is particularly important for studying the internal relationship between sugar beet growth and nitrogen fertilizer.In this experiment,different sugar beet varieties were treated with different nitrogen levels(0,120 and 180 kg/hm^(2)),and statistical and correlation analysis were carried out on the indexes of sugar beet root yield,sugar content,chlorophyll content,soluble protein content,etc.,to explore the influence of nitrogen application amount on different growth stages of sugar beet.The results showed that the content of chlorophyll and soluble protein increased significantly with the increase of nitrogen application;compared to N0(0 kg/hm^(2)),the soluble protein content of sugar beet treated with N180(180 kg/hm^(2))increased by 30%on average.The N content in leaves and roots showed a trend of increasing first and then decreasing,but at the same period,the nitrogen content in leaves and roots increased with the increase of nitrogen fertilizer application.Nitrate reductase(NR)activity in sugar beet was inversely related to growth time and positively correlated with nitrogen supply.In the first period(July 6),the NR activity in sugar beet under N180 increased by 68%-91%compared to N0.The correlation analysis showed that the taproot yield of different sugar beet varieties was significantly positively correlated with the amount of nitrogen fertilizer applied,and significantly negatively correlated with the sugar content;The sugar yields under N120(120 kg/hm^(2))and N180 treatments were similar,and the increase in nitrogen application had little impact on the economic value of the sugar beet at this time,and it is speculated that the suitable nitrogen application might be 120-180 kg/hm^(2).This study provides a theoretical basis for rational application of nitrogen fertilizers in sugar beet.