不同茬口对当归根际土壤酶活性及其产量和品质的影响

Effect of different cropping rotations on enzyme activities in rhizosphere soil and production quality of Angelica sinensis

目的研究当归正茬、迎茬、连茬对根际土壤主要酶活性和产量品质的影响。方法采用比色法测定不同茬口当归根际土壤中脲酶、磷酸酶、多酚氧化酶活性,采用高锰酸钾滴定法测定过氧化氢酶活性。结果苗期和收获期连茬土壤中的脲酶和磷酸酶活性显著低于正茬,脲酶活性分别降低16.53%和37.17%,中性磷酸酶活性分别降低28.01%和30.69%;多酚氧化酶活性在整个生育期均是连茬显著高于正茬,苗期、根膨大期和收获期分别比正茬增加15.10%、83.67%、38.53%。连茬当归产量、挥发油和浸出物量均显著低于正茬,分别比正茬下降49.00%、25.26%、12.58%。结论连茬栽培中当归产量、挥发油和浸出物量显著低于正茬;连茬栽培当归根际土壤脲酶和磷酸酶活性显著降低,而过氧化氢酶和多酚氧化酶活性呈升高趋势。

Objective To study the effects of three cropping rotations （i.e. the main cropping, stubble, and continuous cropping） on the soil enzyme activity in rhizosphere soil, yield, and quality of Angelica sinensis. Methods In rhizosphere soil of different cropping rotations, the activities ofurease, phosphatase, and polyphenoloxidase were determined with colorimetry, and the activities ofcatalase with potassium permanganate titration. Results Enzyme activities were strongly affected by different cropping rotations. The activities of urease and phosphatase of main cropping soil were higher than those of continuous cropping soil at the significant level in the seedling and harvest stages. The activities of urease were decreased by 16.53% and 37.17%, the activities of neutral phosphatase 28.01% and 30.69%, respectively. While the activity of polyphenoloxidase increased pronouncedly （15.10%, 83.67%, and 38.53%） in continuous cropping rotation in all growth stages （seedling, root enlargement, and harvest）. The yield, essential oil content, and extract content under continuous cropping were significant lower than those in main cropping （decreasing 49.00%, 25.26%, and 12.58%, respectively）. Conclusion Both yield and quality ofA. sinensis decline, and urease and neutral phosphatase activities ofrhizosphere soil significantly decline in the continuous cropping, while the catalase and polyphenoloxidase activities present rising tendency.