施用沼液对杨树人工林细根形态特征的影响

【目的】 研究施用沼液对杨树人工林细根形态特征的影响,以期为科学利用沼液、优化杨树人工林施肥技术、促进杨树人工林可持续经营提供理论依据。【方法】 2018年10月,在4种长期施用沼液(施用量0、125、250和375 m³/hm²)的杨树人工林野外实验样地,采用连续土钻法钻取不同土壤深度(0~20,≥20~40和≥40~60 cm)土芯样品;在实验室分拣出杨树活细根,经清洗、分级、扫描、烘干、称量,比较不同处理下不同土层1~5级细根平均直径、平均长度和比根长。【结果】 随着沼液施用量的增加,杨树人工林各级细根平均直径和长度呈下降趋势,而比根长呈上升趋势。但不同土层的不同根序细根形态特征对沼液的响应不同:随着土层的加深和细根根序的增加,细根平均直径、平均长度和比根长的变化幅度多呈现减小趋势。【结论】 长期施用沼液可降低杨树人工林细根平均直径和平均长度,提高杨树人工林细根比根长,在土壤表层和低级细根上表现尤为明显。

Effects of applying biogas slurry on the morphological characteristics of fine roots of poplar plantations

【Objective】 The aims of this research are to study the effect of biogas slurry on the morphological characteristics of the fine roots of poplar plantations, and to provide a theoretical basis for the scientific use of biogas slurry, optimization of fertilization techniques for poplar plantations, and promotion of sustainable management of poplar plantations.【Method】 In October 2018, four biogas slurry application levels (0, 125, 250 and 375 m³/hm²) of poplar plantations were used to drill core samples at different soil depths (0-20, ≥20-40 and ≥40-60 cm) by continuous soil drilling. In the laboratory, the living fine roots of poplar were sorted, cleaned, graded, scanned, dried and weighed, and the average diameter, average length and specific root length of 1-5 grade fine roots in different soil layers were compared under different treatments. 【Result】 With the increase of biogas slurry application amount, the average diameter and length of fine roots of poplar plantation at all levels showed a decreasing trend, while the specific root length showed an increasing trend. However, different root layers fine root morphological characteristics of different soil layers respond differently to the biogas: with the deepening of soil layer and the increase of fine root order, the variation amplitude of average diameter, average root length and specific root length of fine roots decreased.【Conclusion】 The long-term application of biogas slurry reduced the average diameter and length and increased the specific root length of fine roots in poplar plantations, especially in the topsoil and lower order of fine roots.