我正在读一本书在paragrapht谈到史前芬兰的农业方法。>进一步北部和东部,更广泛的数量> burn-beat培养,这是一个远离>农业的原始形式。收益率高出很多倍比永久(二十到三十倍)>字段(5 - 10倍),并有多个技术> > >品种——由Henrik Meinander芬兰的历史。其中一个是burn-beating。就像我理解,在burn-beating人们砍伐树木森林和燃烧的表层土。这样他们可以使用3到6年的土壤种植。另一个方法是永久性的。我有搜索互联网。结果我可以是“永久作物”。(这里)[1]在这种情况下人们种树曾经多次在一个字段和收获。 But in another research about prehistoric Finland it was saying: > The site of Orijärvi shows that permanent field cultivation, with > hulled barley as the main crop was conducted from approximately cal AD > 600 onwards. [research link][2] I see that "permanent field cultivation" is different from "permanent crops". Because as far as I know you can not harvest a field in which is sown barley. So what does permanent field mean if prehistoric finns were sowing barley, oat and etc? [1]: https://www.farmfundr.com/blog/what-are-permanent-crops [2]: https://www.researchgate.net/publication/337706536_Prehistoric_cultivation_and_plant_gathering_in_Finland_An_archaeobotanical_study