Smallholder farming in northern Potosi, Bolivia: challenges to local adaptive coupling in an Andean setting

Highland farmers in Northern Potosí, Bolivia practice mixed crop/livestock subsistence agriculture in which extensive rangeland grazing provides nutrients in manure for crop production. Their farms, communities, and outside networks represent a coupled human and natural system where we might expect tight coupling between the environment and management. We analyze soil degradation as a driver of this system and test whether soil nutrient balances correlate to household food security, a locally felt signal necessary for adaptive coupling to sustain productivity. Nutrient balances reveal that soil erosion is a major driver that undermines productive capacity. Farmers’ dependence on ecosystem services in range and crop areas would make this degradation signal seem effective in causing farmers to reduce soil erosion rates. Reduced food security shows evidence for this signal at household scales. However, other processes at both local and regional scales make adaptation difficult and foster maladaptive coupling. Locally, buffering of soil nutrient stocks delays farmers’ perceptions of degradation compared to the nutrient balance approach. Increased grazing of common rangeland enables higher manuring rates with low immediate cost and substitutes for more costly and innovation-intensive reductions in erosion. Lack of credit or other incentives and reduced food security also inhibit households’ adaptive ability. Regionally, outmigration and off-farm income play a role in coping with reduced on-farm productivity and damping the coupling signal. Our work suggests that both local and cross-scale factors play a role in limiting the perception and the response to environmental signals for adaptive coupling by smallholder farmers.