Growth of citrus,apple and other fruit trees in replant woodlands may be significantly reduced due to a replant problem and now it has occurred in intensive cropping systems as well.Soybean is a main crop in the north-east part of China.When soybean is cropped continuously in the same field for years,the yield would be reduced by 10%~30% or more.The phenomenon is called soybean continuous cropping problem(SCCP).For easy management,farmers would rather plant soybean year after year than rotate with maize,or ...