Understanding farmers’ underlying perceptions and knowledge of the impact of trees on-farm is essential to develop appropriate agroforestry practices that meet farmers’ aspirations. Using the Australian-funded Trees for Food Security (T4FS) project as a case study, we obtained quantitative data from questionnaire interviews with 400 smallholder farmers belonging to four farmer categories in the Mt. Elgon region of Uganda. The categories were: (1) those actively participating in the T4FS project from phase 1 (2014); (2) farmers neighbouring those actively participating in the T4FS project from phase 1; (3) farmers actively participating in the T4FS project from phase 2 (2017) and; (4) farmers living distant and unaware of the T4FS project. Farmer perceptions and knowledge of the impact of trees on farm and their management varied across the farmer categories studied. The intended purpose of trees on farm was perceived differently by the four farmer categories (p < 0.05), which may have implications to their adoption and scaling up. Unlike other farmer categories, the majority of farmers actively participating in the T4FS project from phase 1 perceived planting of trees for shade as not being too much trouble for what it is worth (complexity), and that a garden shaded with trees has more general benefits than an unshaded garden (relative advantage). While 50% of farmers actively participating in the T4FS project from phase 1 indicated that they pruned their tree canopies, tree pruning was mainly driven by the need for fuelwood, rather than the need to reduce tree shade. All the four farmer categories perceived that coffee grown under shade was more likely to be infected by diseases than unshaded coffee, attributing it to poor shade tree management. Managing these trees would otherwise control the negative effects of over shading and prolong the period of intercropping. This study shows the importance of context-specific design of research and development projects aiming for local impact.

了解农民对树木对农场影响的潜在看法和知识对于制定满足农民愿望的适当农林业实践至关重要。以澳大利亚资助的粮食安全树木 (T4FS) 项目为案例研究，我们从对山上属于四个农民类别的 400 名小农进行问卷调查中获得了定量数据。乌干达埃尔贡地区。这些类别是：（1）从第一阶段（2014 年）开始积极参与 T4FS 项目的人；(2) 与第一阶段积极参与 T4FS 项目的农民相邻；(3) 从第二阶段（2017 年）开始积极参与 T4FS 项目的农民；(4) 居住遥远且不知道 T4FS 项目的农民。农民对树木对农场及其管理的影响的看法和知识在所研究的农民类别中各不相同。四种农民对农场树木的预期用途有不同的看法（磷 < 0.05），这可能对其采用和扩大规模产生影响。与其他农民类别不同，大多数农民从第一阶段开始就积极参与 T4FS 项目，他们认为种植遮荫树木对于其价值（复杂性）而言并没有太大的麻烦，并且有树木遮荫的花园具有更多的普遍利益比一个没有阴影的花园（相对优势）。虽然从第一阶段开始积极参与 T4FS 项目的农民中有 50% 表示他们修剪了树冠，但树木修剪的主要驱动力是对薪材的需求，而不是减少树荫的需要。所有四个农民类别都认为，在遮荫下种植的咖啡比未遮荫的咖啡更容易感染疾病，这归因于遮荫树管理不善。否则，管理这些树木将控制过度遮荫的负面影响并延长间作期。本研究显示了针对当地影响的研发项目的特定环境设计的重要性。