Soil and water conservation practices (SWCPs) have been implemented in many parts of Ethiopia for the past 4–5 decades, however, farmers’ are destructing the constructed SWCPs claiming lack of short-term benefits like minimizing slope gradient, reducing soil erosion, improving soil fertility and consequently increasing crop productivity. The aim of this study was to investigate the impacts of SWCPs age on maize grain yield, sediment trapping, soil moisture conservation and slope gradient change in Koga catchment, in the northwest highland of Ethiopia. Physical (fanya juu and soil bund) and biophysical (fanya juu integrated with grass) SWCPs were investigated using field experiment. SPSS version 24 software was used for data analysis. Three treatments were designed in three replications: (i) Fields treated with Fanya Juu (FJ), (ii) Fields treated with soil bund (SB), and (iii) Fields treated with a combination of FJ and Grass (G). The investigated SWCPs were grouped into three age classes (<5 years, 5−10 years and >10 years). The result shows that significantly higher maize grain yield was recorded in fields treated with aged SWCPs than recently constructed SWCPs. Maize grain yield was also higher in fields treated with biophysical SWCPs than fields treated with physical SWCPS alone. Unlike aged SWCPs, significantly higher amount of sediment was recorded behind recently constructed SWCPs because of soil erosion from the newly constructed unstable soil ridges in addition to soil erosion from upslope fields. The sediment trapping efficiency of SWCPs decreases as age increases, because the area of sediment deposition was filled by sediment due to lack of maintenance. Aged SWCPs significantly reduced slope gradient due to the long year trapped sediment and man-made ridge lines made during construction. In general, although the investigated SWCPs improved crop grain yield, maintained soil moisture and reduced slope gradient; the effects were insignificant compared with expectations after 4–5 decades. For instance, slope gradient didn’t change to its minimum. Hence, researchers and experts are expected to develop alternative approaches like ‘’Slope Reversing Terrace (SRT)’’ or modify the existing practices, after half of a generation age experience.

在过去的4至5年中，埃塞俄比亚的许多地区都实施了水土保持措施（SWCP），但农民正在破坏已建成的SWCP，声称缺乏短期利益，如最大程度地减少坡度，减少土壤侵蚀，改善水土流失。土壤肥力，从而提高农作物的生产力。这项研究的目的是调查在埃塞俄比亚西北高地科加流域，短链氯化石蜡年龄对玉米产量，沉积物捕集，土壤水分保持和坡度梯度变化的影响。通过田间试验研究了物理（范亚ju和土壤外滩）和生物物理（范亚ju与草结合）SWCP。使用SPSS 24版软件进行数据分析。设计了三种重复处理的三种处理方法：（i）用Fanya Juu（FJ）处理过的田地，（ii）用土壤障壁（SB）处理的田地，以及（iii）用FJ和Grass（G）混合处理的田地。被调查的SWCP分为三个年龄段（<5岁，5-10岁和> 10岁）。结果表明，用老化的短链氯化石蜡处理的田地记录的玉米籽粒产量比新构建的短链氯化石蜡明显高。生物物理SWCP处理的田地玉米单产也高于单独物理SWCPS处理的田地。与老化的SWCP不同，在最近建造的SWCP后面记录到大量的沉积物，这是因为新建造的不稳定土壤脊对土壤的侵蚀以及上坡田的土壤侵蚀。SWCPs的沉积物捕集效率随着年龄的增长而降低，因为由于缺乏维护，沉积物的沉积区域充满了沉积物。多年的SWCP大大减少了坡度，这是由于在施工过程中长期积存了沉积物和人造山脊线。总的来说，尽管所研究的短链氯化石蜡提高了作物的籽粒产量，保持了土壤水分并降低了坡度。与4-5年后的预期相比，影响微乎其微。例如，坡度没有改变到最小。因此，研究人员和专家有望在一代人的经历中获得一半的经验，开发出其他方法，例如“ Slope Reversing Terrace（SRT）”或修改现有做法。与4-5年后的预期相比，影响微乎其微。例如，坡度没有改变到最小。因此，研究人员和专家有望在一代人的经历中获得一半的经验，开发出其他方法，例如“ Slope Reversing Terrace（SRT）”或修改现有做法。与4-5年后的预期相比，影响微乎其微。例如，坡度没有改变到最小。因此，研究人员和专家有望在一代人的经历中获得一半的经验，开发出其他方法，例如“ Slope Reversing Terrace（SRT）”或修改现有做法。