紫花苜蓿根系抗拉力学特性及其影响因素研究

doi:10.13866/j.azr.2023.02.08

摘要/Abstract

摘要：

为分析草本植物单根的抗拉力学特性及其影响因素，以紫花苜蓿为研究对象，选取不同根系直径、根系长度的紫花苜蓿根系在不同加载速率下开展室内单根拉伸试验，定量分析紫花苜蓿单根抗拉力学特性及其在不同影响因素下的变化规律。结果表明：加载速率对紫花苜蓿根系抗拉力和抗拉强度具有极显著影响（P<0.05），且在根系直径<3 mm时，加载速率为500 mm·min^-1时根系抗拉力和抗拉强度最大，而当根系直径相对较粗时，加载速率为100 mm·min^-1时根系抗拉力和抗拉强度最大；根系长度与紫花苜蓿根系抗拉力、抗拉强度之间没有显著差异（P>0.05）；紫花苜蓿根系直径对根系抗拉力和抗拉强度具有显著影响（P<0.001），其与根系抗拉力呈幂函数正相关关系（R²=0.380，P<0.001），与抗拉强度呈幂函数负相关关系（R²=0.363，P<0.001）；通过对紫花苜蓿根系抗拉力学特性的影响因素进行多元线性回归分析，根系直径是影响植物根系抗拉力学特性的最主要因素。

关键词: 紫花苜蓿, 抗拉力学特性, 加载速率, 根系长度, 根系直径

Abstract:

We analyzed the tensile properties and its influencing factors of a single root of the pioneer herbaceous plant alfalfa (Medicago sativa Linn.). Alfalfa roots with different root diameters and lengths were selected for indoor single-root tensile tests under different loading rates. The tensile force and tensile strength of a single root were estimated quantitatively for different root diameters, root lengths, and loading rates. The results showed loading rate had a significant effect on the tensile force and tensile strength of alfalfa roots (P<0.05). For a root diameter less than 3 mm, the tensile force and tensile strength reached their maximum at the loading rate of 500 mm·min^-1. However, when the root diameter was relatively thick, the tensile force and tensile strength of alfalfa roots reached their maximum at the loading rate of 100 mm·min^-1. No significant difference between root length, tensile force, and tensile strength of alfalfa root was observed (P<0.05). The root diameter of alfalfa showed a significant influence on root tensile force and tensile strength (P<0.001). The root diameter was positively correlated with root tensile strength by a power function (R²=0.380, P<0.001) and negatively correlated with root tensile strength by a power function (R²=0.363, P<0.001). The regression model about the impact of various factors on the alfalfa root tensile force and tensile strength showed that root diameter was the main factor affecting the tensile properties.

Key words: alfalfa, tensile mechanical property, loading rate, root length, root diameter

毛正君,耿咪咪. 紫花苜蓿根系抗拉力学特性及其影响因素研究[J]. 干旱区研究, 2023, 40(2): 235-246.

MAO Zhengjun,GENG Mimi. Study on tensile mechanical properties of alfalfa roots and the influencing factors[J]. Arid Zone Research, 2023, 40(2): 235-246.

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分级	根系直径/mm	加载速率/（mm·min^-1）	根系长度/mm
1	2~3	20	0~50
2	3~4	50	50~100
3	4~5	100	100~150
4	>5	200	150~200
5	-	500	200~250

	根系长度		根系直径
	数量/个	平均值	数量/个	平均值
1	1	-	93	2.65±0.23a
2	29	83.36±15.27a	13	3.44±0.29b
3	178	126.06±13.27b	59	4.32±0.28c
4	69	181.47±15.01c	11	5.41±0.58d
5	19	209.54±11.82d	0	-

加载速率/（mm·min^-1）	根系样本数量/个	平均根系直径/mm	平均抗拉力/N	平均抗拉强度/MPa
20	26	3.27±0.55	141.00±36.14	17.50±5.37
50	43	3.52±0.67	152.86±45.08	16.44±5.18
100	37	3.47±0.76	184.78±117.94	19.18±6.43
200	49	3.32±0.79	168.06±64.80	19.96±5.59
500	23	3.34±0.70	161.42±70.55	18.96±5.97

抗拉特性	根系样本数量/个	F值		P值
抗拉特性	根系样本数量/个	加载速率	根系直径	加载速率	根系直径
抗拉力	178	3.474	122.348	0.009^**	<0.001^**
抗拉强度	178	3.474	89.298	0.009^**	<0.001^**

抗拉特性	根系样本数量/个	F值	P值
抗拉力	78	1.002	0.397
抗拉强度	78	1.452	0.235