在批林批孔运动的推动下,在“农业学大寨”的群众运动中,平整土地、大搞桑地园林化的工作,在各地普遍开展。这是改造老桑园,解决土地零星分散、不能灌溉以及水土流失等问题的根本性措施。各地实践证明,平整土地可以为实现桑园高产创造良好条件。然而土地平整造成的土壤差异也带来了一些新的问题,主要表现在桑树生长不匀,影响桑园的进一步增产。过去多数人认为这种土壤差异将随着时间延续,逐渐缩小。因而,没有给予足够的重视。我们针对这一问题,在桑园内做了较系统的观察,寻找 In the mass movement of “learning from agriculture and learning from Dazhai”, the work of leveling up the land and popularizing the mulberry fields and landscaping was carried out in all parts of the country. This is a fundamental measure to rehabilitate the old mulberry field and solve the problems of sporadic land dispersal, non-irrigation and soil erosion. Practice in various places has proved that the formation of land can create good conditions for the high yield of mulberry. However, the soil difference caused by land leveling also brought some new problems, mainly manifested in the uneven growth of mulberry trees and the further increase of mulberry fields. In the past most people think that this soil difference will gradually reduce over time. Thus, not enough attention has been given. We address this issue in the mulberry field to do a more systematic observation, looking for