Diversity of smallholder rice farmers’ knowledge, perceptions and management practices for soil health in the growing market and agrochemicals-led agriculture in Tanzania

Agriculture in Tanzania, as in many sub-Saharan African countries, is experiencing political-economic transformations toward intensive-input commercial farming. Despite the implications of these farming models for soil health and the long-term sustainability of agricultural landscapes, little is known about how farmers understand and respond to these changes. This paper examined farmers’ experiential knowledge, perceptions, and soil health management practices within a transforming agricultural landscape in the Kilombero valley floodplain, in Tanzania. The paper adopted a mixed-methods approach integrating both qualitative and quantitative methods. Drawing on their experiential knowledge, farmers perceived substantial changes in soil health over time. Traditional soil health indicators such as the presence or disappearance of earthworms, responsiveness of agrochemicals, soil workability, and trends of soil color, crop yield, and pest prevalence served an invaluable purpose in diagnosing soil health conditions. For many years, they relied on practices like crop rotation, intercropping, reduced tillage, and fallowing for improving soil health and dietary needs. However, in recent years, they have been increasingly switching to monocropping of high-economic value crops for income generation. Farmers perceived that the expansion of market opportunities and production incentives due to agricultural commercialisation has contributed to intensive use of agrochemicals. Consequently, they increasingly perceived these agricultural transformations as associated with soil health deterioration. The paper further revealed a substantial decline in rice production during the most recent cropping season, despite growing investments, reflecting the reconfiguration of the KVF. Overall, the paper contributes to discussions on the political ecology of agriculture and its implications for smallholder livelihoods. Profit-led agricultural interventions have undermined farmers’ long-standing adaptive strategies and are widely perceived to compromise the habitability of the KVF. Among others, this paper recommends integrating farmers’ knowledge and management practices into agricultural policies and institutional frameworks for sustainable soil health and agricultural productivity.