水旱轮作减轻三七连作障碍的潜势分析

The Potential of Alternative Water Logged and Dryland Conditions to Relieve the Continuous Cropping Obstacle of Panax notoginseng

三七是中国最常用大宗药材之一,但因其适宜生境狭窄,忌连作性很强,可流转土地紧张,已致其连作障碍十分严重。水旱轮作使土壤系统在不同季节间干湿交替变换,能有效减少土壤中有害物质,增加土地复种指数,在水(稻)旱(蔬菜、玉米)轮作中已被证实能有效减轻连作障碍。本文综述了水旱轮作下连作土壤理化性状包括土壤结构、矿物元素、有机质、次生盐渍化和酸化、酶活性和微生物群落、化感自毒物质的改善性变化,及其对病虫害和杂草的抑制作用。通过潜势分析认为水旱轮作能有效减轻三七连作障碍,但还需要合理安排茬口,并多施有机肥和绿肥以提升土壤肥力。

Panax notoginseng （Burkill） F. H. Chen is one of traditional Chinese medicines that is wide- ly used. It dislikes continuous cropping, but its suitable habitat is too narrow, which has lead to severe continuous cropping obstacle （CCO） due to the limit of farm land. The alternative water logged and dryland cropping （AWLDC） can make soil change between dry and logged conditions in different sea- sons, which can efficiently reduce harmful materials in soil and increase multiple crop index. It has been proven that rotations of rice and vegetables or maize can effectively relieve CCO. In this paper, how the physical and chemical characteristics of CCO soils were improved under AWLDC was introduced, inclu- ding soil structure, mineral elements, organic matter, secondary salinization, enzyme activity, microbial populations and allelopathic chemicals. The effect of AWLDC on the control of pests and weed was also reviewed. Based on these analysis, we believe in that AWLDC could efficiently relieve the CCO of P. notoginseng, accompanying with rational cropping arrangement and fertilizer management.