The Role of Extension and Information in the Adoption of Integrated Soil Fertility Practices and Impacts on Farmers' Welfare: Evidence from a Randomized Controlled Trial in Ethiopia

土地严重退化是农业生产力可持续集约化的主要挑战之一。土壤退化与土壤肥力下降和产量不足有关，这对撒哈拉以南非洲小农家庭的生计构成了特别的威胁。为了恢复、维持和增加土壤功能，已经开发了广泛的综合土壤肥力管理（ISFM）技术。尽管这些做法有潜在的好处，但撒哈拉以南非洲地区小农的采用率仍然很低。大量的文献集中于调查采用的决定因素，主要使用横断面数据。这些研究往往指出缺乏信息是阻碍采用的一个重要障碍，因此强调农业推广服务对促进技术更广泛传播的重要性。尽管具有很高的政策相关性，但迄今为止，关于推广项目对农民知识和采用行为的影响的严格证据相对较少。本研究提出了一项随机对照试验，以评估分散、农民对农民推广和视频媒介信息提供对农民知识、自我效能和采用ISFM实践的影响。因此，它将为推广一套复杂的农业技术的低成本推广方法的有效性提供严格的证据。此外，异质性治疗效果将特别关注社区层面的社会资本进行分析。鉴于分散式推广方法依赖于农民对农民的知识转移，我们预计其有效性取决于社区中已有社会资本的程度。最后，我们的目标是评估与采用ISFM实践相关的福利效应。拟议的研究基于埃塞俄比亚高地2595个农户的现有基线数据。我们计划从相同的家庭中收集后续数据，并从210个家庭的随机子样本中收集农作物减产的数据。计量经济学技术将用于估计意向治疗效应的推广和信息干预和分析异质性治疗效果。此外，我们将用自报告的产量数据估计地块水平的产量函数。为了验证，8000块土地上的作物收割数据来自大约2000块土地。600块。最后，利用内生转换回归等技术，我们估计了家庭层面的收入效应。本研究将通过大规模随机对照试验对可持续农业技术的输送机制提供严谨的证据，从而推动研究方向的发展。这些见解对于决策者和发展实践者设计和扩大干预措施，从而更有效地实现发展目标也很有价值。

High levels of land degradation represent one of the major challenges for sustainable intensification of agricultural productivity. Soil degradation is associated with declining soil fertility and yield deficits that represent a particular threat for the livelihoods of smallholder farm households in Sub-Saharan Africa. A wide range of integrated soil fertility management (ISFM) techniques have been developed to restore, maintain and increase soil functions. Despite the potential benefits of these practices, adoption rates among smallholder farmers in Sub-Saharan Africa remain low. A large body of literature focuses on investigating the determinants of adoption using mostly cross-sectional data. These studies often identify the lack of information as an important barrier to adoption and accordingly emphasize the importance of agricultural extension services to promote a wider diffusion of the technologies. Despite high policy relevance, there is comparatively little rigorous evidence on the impact of extension programs on farmers' knowledge and adoption behavior to date. This study proposes a randomized controlled trial to assess the effects of decentralized, farmer-to-farmer extension and video-mediated information provision on farmers' knowledge, self-efficacy, and adoption of ISFM practices. It will thus provide rigorous evidence on the effectiveness of a low-cost extension approach to promote a complex package of agricultural technologies. Furthermore, heterogeneous treatment effects will be analyzed with a particular focus on community-level social capital. Given that the decentralized extension approach relies on farmer-to-farmer knowledge transfer, we expect its effectiveness to be conditioned by the extent of pre-existing social capital in a community. Finally, we aim to assess the welfare effects associated with the adoption of ISFM practices. The proposed study builds on available baseline data from 2595 farm households in the Ethiopian highlands. We plan to collect follow-up data from the same households, and complement our data set with crop cuts from a random sub-sample of 210 households. Econometric techniques will be used to estimate the intention-to-treat effects of the extension and information interventions and to analyze heterogeneous treatment effects. In addition, we will estimate plot-level yield functions with self-reported yield data from approx. 8000 plots and - for validation - with crop-cut data from approx. 600 plots. Finally, employing techniques such as endogenous switching regression, we estimate income effects at the household level. The proposed study will advance the research direction by providing rigorous evidence from a large-scale randomized controlled trial on delivery mechanisms for sustainable agricultural technologies. These insights will also be valuable for policy makers and development practitioners for designing and up-scaling interventions and thereby achieving development goals more effectively.