大豆连作减产主要障碍因素的研究 Ⅰ.连作大豆根系腐解物的障碍效应

STUDY OF MAIN FACTORS CAUSING YIELD DECREASE OF CONTINUOUS CROPPING SOYBEAN Ⅰ.Effects of Decomposing Matters of Roots Continuous Cropping Soybean

通过恒温腐解大豆根系所得到的腐解液处理大豆种子表明，腐解１个月的大豆根系腐解液可抑制大豆种子萌发生长，抑制率为１８％－２２％，经４个或６个月腐解的大豆根系腐解液对大豆种子萌发的影响差异不显著，大豆根系表面水浸液对大豆种子萌发不产生显著影响。通过大豆根拌土盆栽试验表明：大豆根系对下茬大豆生长有显著影响，正茬土拌大豆根系较不拌大豆根系的处理减产６％－２４％，并且随着加入根系量的增多，减产幅度增加，大豆根系拌土腐解一年后再种植大豆，对产量和生育期各阶段生物量不产生影响。根系腐解液和大豆根系拌土盆栽试验证明了生产上大豆根对下茬大豆从种子萌发开始，就发生抑制，随时间的延长，抑制作用减弱，生产上约经两年左右，抑制作用彻底消失，由此表明了大豆根系腐解中间产物是大豆连作主要障碍之一。

Abstract In this study, soybean seeds were treated by decomposed liquids from soybean roots under fixed temperature. The result shows that, one-month decomposed liquid inhibits the germination and growth of soybean, rating between 18% and 22%; four or six month decomposed liquid has on significant influence on the germination of soybean. In pot culture experiment, mixing earth with soybean roots, showed that, soybean root affected the following soybean significantly. Compared with control rotatrion field earth mixed with soybean roots reduced 6%-24% yield, and the decrease became larger with the increase of mixed soybean roots. Through one year's decomposition, soybean roots mixed with earth had on in further influnce on soybean's growth and yield. The above experment demonstrates that in soybean production, soybean roots begin to inhibit following soybean growth at germination, and inihbition effect can last for two years.