刈割对豆科和非豆科植物叶片内稳性及叶片土壤化学计量特征的影响

Effects of Mowing on Leaf Internal Stability and Leaf and Soil Stoichiometric Characteristics of Legumes and Non-legumes

为了明确豆科和非豆科植物在生长发育过程中养分利用策略的差异。本试验以典型豆科植物苜蓿(Medicago sativa)和非豆科植物菊苣(Cichorium intybus)为研究对象。分别于2021年7月14日(播种后第60 d)、2021年8月3日(播种后第80 d)和2021年8月24日(播种后第100 d)采集地上部分和土壤样品,计算生态化学计量内稳性。结果表明:2种植物叶片氮钾比在播种后第80 d刈割显著高于播种后第100 d刈割,而叶片磷钾比表现相反趋势(P<0.05)。播种后第100 d刈割,苜蓿叶片全氮含量和氮磷比显著高于菊苣(P<0.05)。菊苣和苜蓿的叶片氮、磷和钾的内稳性指数均表现为H N>H K>H P,表明植物对氮元素的调控能力更强。这项研究发现叶片化学计量特征存在物种间差异,这种差异是物种对环境长期适应的结果,与自身遗传特征有关,具有相对稳定性,并非全部受制于土壤养分的影响。

To explore nutrient utilization variations between legumes(Medicago sativa)and non-legumes(Cichorium intybus)during growth,we sampled above-ground plant parts and soil at three mowing intervals(60,80,and 100 days after seeding),and computed ecological stoichiometric homeostasis.The findings revealed the leaf N∶K ratio was the highest at the 80 th day,contrary to the leaf P∶K ratio.At the 100 th day,M.sativa showed significantly higher total nitrogen(TN)and N:P ratio in leaves than C.intybus.The homeostasis index for nitrogen,phosphorus,and potassium in C.intybus and M.sativa leaves was H N>H K>H P,underscoring stronger nitrogen regulation of plant.This study unveiled leaf stoichiometric differences between species,stemming from long-term environmental adaptation,genetic traits,stability,and partial autonomy from soil nutrient impact.