This thesis explores how information and communication technologies (ICTs) can contribute to sustainable agricultural development. ICTs have for a long time been seen as important tools to support agriculture, in particular supporting the resource-constrained agricultural extension services of the Global South. However, previous research has largely failed to consider how ICTs can play a role in sustainable, agroecological farming. Not only that, existing approaches to agricultural ICTs have by and large failed to ensure that the interventions themselves are sustainable. Sustainable farming demands a holistic approach to agriculture, which extends to the way technologies such as ICTs are employed. The question of sustainability is critical for a sector that employs nearly a third of all workers worldwide, and a majority of those who are classified as poor. This has become especially acute considering the effects of the global climate crisis. Deploying technological interventions that cannot be sustainably maintained and do not take into account whether the agriculture they are promoting is sustainable, can only serve to exacerbate the issues at hand. Through action research conducted together with a non-profit organisation, Development Research Communication and Services Centre (DRCSC), in West Bengal in India, I have explored how to address ICTs in sustainable agriculture. In our work, we have developed an approach to ICTs that is both sustainable and also contributes to the long-term resilience and sustainability of the agroecosystem within which DRCSC operates. This required recognising the specific nature of the knowledge ecosystem of sustainable agriculture and understanding the way in which technology interventions can operate within the same. Understanding development as an expansion in capabilities, the emphasis of this process has been on DRCSC developing collective capabilities of technology stewardship, i.e. individual and organisational capacities to critically assess and constructively approach technology in ways that they (DRCSC) have reason to value. As a result of the project, we have developed two interventions that are currently sustainably adopted within the organisation, helping them in their work to support resource-poor, smallholder farmers. These interventions have been built incorporating values of self-reliance, autonomy and low resource use that are central to DRCSC in particular and to agroecology in general. The interventions, as well as the way that DRCSC and I developed them, illustrates how ICTs can be approached in the space of sustainable agricultural development. Drawing on a critical understanding of sustainability and technology, this thesis, however, not only informs approaches to ICTs in agriculture but ICT in development in general. Critical technology stewardship is an approach that can help researchers in ICT4D to engage in ways that are sustainable and lead to sustainable outcomes. Stewarding provides a means by which to incorporate situated understandings of the role that ICTs can play in any given context. It frames how ICT designers and researchers can participate ethically in supporting long-term development outcomes. It serves as a practical example of approaching ICT in development in a way that combines concerns for sustainability and resilience with a capabilities perspective on development.