持续施用生石灰对早竹笋品质及竹材力学性质的影响

Quality of Bamboo Shoots and Physico-mechanical Properties of Culms of Phyllostachys violascens under Continuous Application of Lime

研究生石灰用量对早竹笋品质及竹材物理力学性质的影响,为早竹林土壤修复中石灰的合理施用提供科学依据。采用随机区组设计,在早竹林中建立10 m×10 m的小区12个,分别设置CK、SH1、SH2、SH3等4个处理,生石灰用量分别为0、1 500、4 500、7 500 kg·hm-2,重复3次。连续施用后3 a后,采集竹笋、竹秆样品,分析笋样中的营养元素和竹材样品的物理力学性质。结果表明,石灰施用后早竹笋中钙含量显著提高了32.46%~48.5%(P<0.05),竹笋铜、铅、镉含量显著下降了15.1%~20.8%,16.6%~19.5%,17.1%~21.0%(P<0.05);施用石灰显著降低了1 a生竹材径向、弦向干缩系数(P<0.05);竹材顺纹抗拉强度和顺纹抗弯强度则表现为SH3处理的1 a生竹材显著高于CK(P<0.05),而2 a的SH2、SH3显著高于CK(P<0.05)。早竹笋钙、镁营养元素含量与土壤交换性钙、镁含量之间具有显著(极显著)正相关,笋中铜、铅、镉含量与土壤有效态元素的相关性达极显著水平,竹材顺纹抗拉强度、顺纹抗弯强度与土壤交换性钙之间有显著性正相关。

In order to explore the effects of lime application on the quality of Phyllostachys violascens shoots and mechanical properties of bamboo,and to provide a scientific basis for soil remediation,12 sample plots were established with randomized block design,4 treatments of lime were set as 0(CK),1 500(SH1),4 500(SH2),and 7 500 kg·hm-2(SH3),They were repeated for 3 times.The nutrient elements of bamboo shoots and mechanical properties of bamboo culms were analyzed after 3 years of management.The results indicated that the Ca content significantly increased by 32.46%~48.5%(P<0.05),Cu,Pb and Cd content significantly decreased by 15.1%~20.8.3%,16.6%~19.5%,and 17.1%~21.0%(P<0.05)respectively.Compared with the CK,the radial and chord shrinkage coefficients of the one-year-old culms were significantly reduced(P<0.05).The tensile and flexural strength of the one-year-old bamboo under SH3 treatment and the two-year-old bamboo under SH2 and SH3 treatments were significantly higher than that of the CK(P<0.05).There was a significant positive correlation between the Ca and Mg contents in bamboo shoots and the exchangeable Ca and Mg contents in soil.In addition,the correlation between Cu,Pb and Cd in bamboo shoots and available elements in soil were extremely significant,there also existed a significant positive correlation between the tensile,flexural strength and the exchangeable Ca content in soil.