In organic farming the control of perennial weed species, in particular Cirsium arvense, can be a major concern for farmers, especially if there is no regulation through perennial forage production. To test whether the stubble cleaner (SC), an enhanced skim plow (PL), is as effective in the control of C. arvense and other weeds as conventional ploughing and perennial forage production, an organic field experiment was established. Three different tillage/crop rotation systems were compared: an SC system and a PL system, both in a cereal-based crop rotation and an additional PL system in a crop rotation that included a perennial alfalfa–grass mixture (PLALF). In the SC system, tillage was carried out solely with the SC, while in the PL and PLALF systems, ploughing was alternated with chiseling. In the fifth year, each main plot was divided into subplots, and seven different cover crop treatments were integrated into each of the three systems. The effects of the three systems and the cover crop treatments on weed cover and density, weed biomass, and weed diversity in the sixth and seventh year of the experiment are the subjects of this paper. The choice of cover crop species was of minor importance for weed control. The PLALF system was generally more effective in controlling C. arvense than the PL and SC systems. No significant differences between the PL and SC systems regarding the control of C. arvense could be identified in four of five assessments. The SC system had significantly higher total weed density than the PLALF and PL systems in both years. However, the differences in weed emergence between the PL and SC systems diminished until the assessment of weed cover and biomass in the main crops, when no significant differences between these two systems (2012) or no differences at all (2013) could be identified. Species richness was not significantly influenced by the tillage/crop rotation system in both years. Evenness and Shannon–Wiener index were significantly higher in the PLALF and PL systems than in the SC system on most assessment dates in 2012. In 2013 there was no clear trend regarding evenness and Shannon-Wiener index probably due to a hoeing operation.. In conclusion, for weed control, the choice of crop rotation was more important than the choice of tillage method, while for the diversity of the weed community, the choice of tillage method was more important than the crop rotation.

中文翻译：

---

在德国的有机耕作系统实验中，不同的耕作方式可促进杂草多样性，而多年生苜蓿草混合物可促进杂草控制

在有机农业中，控制多年生杂草，特别是刺槐，对于农民来说可能是一个主要问题，特别是如果没有通过多年生草料生产进行监管。测试残茬清理器 (SC)，一种增强型脱脂犁 (PL)，是否同样有效地控制C. arvense和其他杂草作为常规耕作和多年生牧草生产，建立了有机田间试验。比较了三种不同的耕作/作物轮作系统：SC 系统和 PL 系统，两者都在以谷物为基础的轮作中，以及在包括多年生苜蓿草混合物 (PLALF) 的作物轮作中的附加 PL 系统。在 SC 系统中，仅使用 SC 进行耕作，而在 PL 和 PLALF 系统中，犁耕与凿凿交替进行。在第五年，每个主小区被划分为子小区，三个系统中的每一个都集成了七种不同的覆盖作物处理。在实验的第六年和第七年，三种系统和覆盖作物处理对杂草覆盖和密度、杂草生物量和杂草多样性的影响是本文的主题。覆盖作物种类的选择对于杂草控制的重要性不大。PLALF 系统通常更有效地控制C. arvense比 PL 和 SC 系统。PL 和 SC 系统在控制方面没有显着差异C. arvense可以在五项评估中的四项中确定。在这两年中，SC 系统的总杂草密度显着高于 PLALF 和 PL 系统。然而，PL 和 SC 系统之间杂草出现的差异逐渐减小，直到评估主要作物的杂草覆盖率和生物量，这两个系统之间没有显着差异（2012 年）或根本没有差异（2013 年）。两年的耕作/轮作系统对物种丰富度没有显着影响。在 2012 年的大多数评估日期，PLALF 和 PL 系统的均匀度和香农-维纳指数明显高于 SC 系统。2013 年，可能由于锄头作业，均匀度和香农-维纳指数没有明显趋势。结论，对于杂草控制，