高寒区轮作模式对当归田土壤特性及药材产量的影响

连作重茬造成当归产量逐年下降。采用药用植物秦艽(QJ)、羌活(QH)轮作当归(DG),以当归连作为对照,通过测定土壤和药材产量指标,利用主成分分析确定各指标权重,并结合隶属综合因子分析和聚类分析,旨在揭示不同药用作物轮作当归对土壤环境与药材产量的影响,为筛选适宜当归栽培的轮作模式提供科学依据。结果表明,不同作物轮作对当归田土壤特性和药材产量均具有显著影响,秦艽轮作当归可有效改善土壤特性,使当归成药期土壤磷和钾含量处于较低水平,而有机质维持在较高水平,对土壤水分的季节调控作用更为显著,与当归连作相比较,当归成药率提高94.10%,药材单根鲜重和药材鲜产量分别提高53.46%和125.56%,而羌活轮作当归土壤pH最高,有机质含量最低,当归连作土壤有机质含量虽高,但土壤富集磷和钾,对土壤水分季节性调控作用最小,当归成药率和药材产量均低。不同轮作模式当归成药率和药材产量依次为秦艽-当归>当归-当归>羌活-当归,综合指数大小依次为秦艽-当归(0.8132)>羌活-当归(0.3315)>当归连作(0.2051)。聚类分析将3种轮作模式分为三大类,重复小区亚类间距离均小,说明不同作物轮作对土壤的调控作用不同,高寒产区秦艽轮作当归是优化调控土壤环境,提高当归产出性能的有效轮作模式。

Effect of crop rotation patterns on field soil properties and medicinal material yield for Angelicae sinensis in alpine regions

Continuous cropping causes Angelica sinensis (DG) medicinal yield to reduce year by year. In order to study the effects of crop rotation patterns on soil factors and the medicinal yield of A. sinensis, data on relevant soil and yield factors were collected from residue sites where A. sinensis is grown in rotation with other medicinal crops such as Gentiana macrophylla (QJ-DG) and Notopterygium incisum (QH-DG), and compared with data from sites where A. sinensis is grown in continuous cropping systems (DG-DG, or control). The data were assessed by membership function and cluster analysis so to provide an objective basis for classifying the rotation pattern. It was found that the rotation patterns had significant effects on the soil properties and the medicinal yield of A. sinensis. The QJ-DG rotations effectively improved the soil properties, resulting in higher organic matter, but lower total K and P. Notably, increased soil organic matter in these systems was linked to improved soil water retention which in turn increased patent medicine plant rate by 94.10%, fresh individual root weight by 53.46% and total fresh medicinal yield by 125.56%, compared with DG-DG. However, in contrast, QH-DG rotations showed higher pH and lower total organic content, but higher organic content rich in P and K, and lower soil water retention appeared in the DG-DG control sites. Thus data from all sites were clustered into three categories ranked for medicinal productivity of A. sinensis as QJ-DG>DG-DG>QH-DG and comprehensive scored as QJ-DG (0.8132)>QH-DG (0.3315)>DG-DG (0.2051) in the cluster analysis. In summary, the crop rotation used has affected soil properties and growing A. sinensis in rotation with G. macrophylla improved the soil environment, resulting in the higher medicinal root yield.