Conservation agriculture (CA) systems represent a set of three soil management principles: minimarbance, permanent soil cover and crop rotations ‐ whereas the CA‐based systems in this study add the bed and furrow tillage techniques as integral elements of CA. Studies on the effects of long‐term CA‐based systems on soil health and crop productivity are rare globally, particularly in Ethiopia. This study aimed at investigating the long‐term (2005–2013) influence of CA‐based systems on soil health and crop productivity in northern Ethiopia. The treatments we used include two types of CA‐based systems (permanent raised bed PRB and contour furrowing CF) and conventional tillage (CT) arranged in a randomized complete block design. Soil samples were collected at 0–10 cm soil depth to assess soil health. Piecewise structural equation modeling (PSEM) was used to analyze linkages between management practices, soil health and crop productivity. Arbuscular mycorrhizal fungi spore abundance and root colonization was higher in PRB followed by CF compared to CT (p < 0.05). Significantly different soil N of 1.4 and 0.9 g kg⁻¹ and available P of 6.7 and 4.1 ppm were recorded for PRB and CT, respectively. Higher straw and grain yield of 12 and 4.3, 10 and 3.5, 8 and 2.8 t ha⁻¹ were recorded for PRB, CF and CT, respectively. Outputs of the PSEM highlighted two pathways in which CA‐based systems contributed to improved productivity: (a) via higher density of bacteria and improved hydraulic conductivity, and (b) via higher density of fungi and increase soil organic carbon content in the topsoil. The study concludes that CA‐based systems have the potential to improve crop productivity through improved soil health.

中文翻译：

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埃塞俄比亚提格雷地区基于保护性农业的系统中9年永久性高架床和等高垄沟对土壤健康的影响

保护性农业（CA）系统代表了一套三项土壤管理原则：微耕作，永久土壤覆盖和作物轮作-而本研究中基于CA的系统将耕作和耕作耕作技术作为CA的组成部分。在全球范围内，尤其是在埃塞俄比亚，对基于长期CA的系统对土壤健康和作物生产力的影响进行的研究很少。这项研究旨在调查基于CA的系统对埃塞俄比亚北部地区土壤健康和作物生产力的长期影响（2005-2013年）。我们使用的处理方法包括两种基于CA的系统（永久性高架床PRB和等高线犁沟CF）和常规耕作（CT），以完全随机区组设计方式进行布置。在0-10厘米的土壤深度收集土壤样品以评估土壤健康状况。分段结构方程模型（PSEM）用于分析管理实践，土壤健康和作物生产力之间的联系。与CT相比，PRB其次是CF的丛枝菌根真菌孢子丰度和根定殖率高于CT（p  ＜0.05）。对于PRB和CT，分别记录的土壤N分别为1.4和0.9 g kg ^-1显着不同，有效磷为6.7和4.1 ppm。对于PRB，CF和CT，分别记录到较高的稻草和谷物产量分别为12和4.3、10和3.5、8和2.8 t ha ^-1。PSEM的输出突出了两种途径，其中基于CA的系统有助于提高生产力：（a）通过提高细菌密度和改善水力传导率，（b）通过提高真菌密度和增加表土土壤有机碳含量。研究得出结论，基于CA的系统有潜力通过改善土壤健康状况来提高作物生产力。