Li Chongwei, Chen Guozhong, Zhang Jianlong, Zhu Ping, Bai Xinfu, Hou Yuping, Zhang Xingxiao
School of Life Sciences, Ludong University, Yantai, 264025, China.
Sci Rep. 2021 Mar 3;11(1):5068. doi: 10.1038/s41598-021-84436-x.
This study aims to verify the time-variant feature of American ginseng (AG) continuous cropping obstacles and to explore the factors impeding continuous cropping. We verified the feature with a plant-soil feedback pot experiment and then investigated the factors by comparing the properties of control soils that had not been previously used for growing ginseng (CS) with those of soils with a 10-year-crop-rotation cycle following the growth of AG (RS). It's found that the survival rate of AG in RS was lower than that in CS. The RS had lower pH, available potassium content, and urease activity. Additionally, p-coumaric, p-hydroxybenzoic, vanillic, caffeic, and cinnamic acid levels were lower in RS than in CS, but salicylic acid levels showed the opposite pattern. RS had higher Rhodanobacter and lower Acidothermus, Sphingomonas relative abundances in bacterial community. It's also found that many bacteria were substantially correlated with phenolic acids and soil physiochemical properties. Results indicate that even after 10-year crop rotation, the negative effects of prior continuous cropping of AG has not been eliminated. The growth of AG can be affected negatively with deterioration of soil physicochemical properties and with lower levels of phenolic acids which promote pathogen reproduction. Probiotics reduction also weighs. Moreover, biotic factors are interrelated with abiotic ones. Therefore, it can be inferred that the comprehensive change of soil properties is the main obstacle for continuous cropping.
本研究旨在验证西洋参连作障碍的时变特征，并探究阻碍连作的因素。我们通过植物-土壤反馈盆栽试验验证了该特征，然后通过比较先前未用于种植人参的对照土壤（CS）与种植西洋参后经过10年轮作周期的土壤（RS）的性质来研究这些因素。结果发现，RS中西洋参的成活率低于CS。RS的pH值、有效钾含量和脲酶活性较低。此外，RS中对香豆酸、对羟基苯甲酸、香草酸、咖啡酸和肉桂酸的含量低于CS，但水杨酸含量呈现相反的模式。RS在细菌群落中的红杆菌相对丰度较高，嗜酸热放线菌、鞘氨醇单胞菌相对丰度较低。还发现许多细菌与酚酸和土壤理化性质密切相关。结果表明，即使经过10年轮作，先前西洋参连作的负面影响仍未消除。西洋参的生长会受到土壤理化性质恶化和促进病原菌繁殖的酚酸水平降低的负面影响。益生菌数量减少也有影响。此外，生物因素与非生物因素相互关联。因此，可以推断土壤性质的综合变化是连作的主要障碍。
