施钾对苇状羊茅生长、生理特性及钾吸收的影响

Effects of potassium fertilizer application on thegrowth and physiology characteristics andpotassium uptake of Festuca arundinacea

摘要:

【目的】 明确钾肥施用对苇状羊茅（Festuca arundinacea）生长、生理特性的影响，确定苇状羊茅适宜的钾肥用量和钾营养诊断指标。【方法】 通过盆栽试验，研究苇状羊茅地上部生长、生理和钾素养分吸收对不同钾肥用量（K2O 分别为0、18、36、54 g/m²）的响应。【结果】 随钾肥用量的增加，苇状羊茅各生育阶段的株高和地上部干物质量均呈先升后降的变化趋势，钾肥用量36 g/m²时达最大值；出苗后50~137 d 和0~50 d 植株株高增量和干物质累积速率较大。施用钾肥36 g/m² 有利于促进植株地上部钾的吸收，提高植株叶片的光合色素含量、抗氧化酶（POD）活性和可溶性蛋白含量，降低丙二醛（MDA）含量。增加钾肥用量提高了苇状羊茅栽培体系的钾素损失风险。适宜苇状羊茅生长的钾肥用量范围为K2O 7. 0~49. 9 g/m²，获得80% 最大地上部干物质量的地上部钾临界浓度为10. 8 g/kg。【结论】 钾肥施用对苇状羊茅生长和生理特性影响显著，钾肥用量7. 0 g/m² 和地上部钾浓度10. 8 g/kg可分别作为苇状养护管理的钾肥用量推荐和植株钾营养诊断参考。

Abstract:

【Objective】 To elucidate the impact of potassium（ K） fertilizer application on the growth and physiol-ogy characteristic of Festuca arundinacea，and to establish the appropriate K fertilizer application rate and K nutritiondiagnosis index.【Method】 A pot experiment was conducted to investigate the responses of shoot growth，physiologyand K absorption characteristics in Festuca arundinacea under various K application rates （0，18，36，54 g/m²）.【Result】 With an increase in K fertilizer application，the plant height and dry matter accumulation in the shoot at eachgrowth stage exhibited an initial increase followed by a decrease，reaching their maximum value at a K application rateof 36 g/m². The plant height increment and dry matter accumulation rate were notably higher at 50~137 days and 0~50 d after emergence. The application of K fertilizer 36 g/m² proved beneficial for enhancing K absorption in the plantshoot，elevating photosynthetic pigment content，antioxidant enzyme （POD） activity，soluble protein content in theleaves，while reducing malondialdehyde （MDA） content. However，it is noteworthy that an excessive amount of Kfertilizer increased the risk of K loss in the cultivation system of Festuca arundinacea. The optimal range for K fertil-izer application in promoting Festuca arundinacea growth was found to be 7. 0~49. 9 g/m²，with the critical K concen-tration required for 80% of the maximum shoot dry matter accumulation identified as 10. 8 g/kg.【Conclusion】 Theapplication of K fertilizer exerted significant effects on the growth and physiological characteristics of Festuca arundi-nacea. The potassium application rate of 7. 0 g/m² and the K concentration of 10. 8 g/kg in plant shoot could serve asvaluable references for K fertilizer recommendation and K nutrition diagnosis in the conservation and management ofFestuca arundinacea，respectively.