The debate over sustainable intensification has hinged on private incentives to abate land degradation. Largely missing is the role of social capital in both creating incentives and removing barriers to soil conservation. Yet soil conservation embodies the externality problem that bedevils so many aspects of natural resource management. Action by one farmer to reduce water or wind erosion may benefit neighboring fields by slowing the rate of water or wind movement across those lands. Yet these benefits are not fully captured by the farmer making the conservation investment. However, when economic agents care for one another, these externalities can be internalized, reducing the individual�'s disincentive to perform a socially level of natural resource conservation. Likewise, community organizations may provide collective capital and labor to overcome adoption barriers faced by individuals. The twin hypotheses that 1) farming practices influence soil erosion and 2) social capital influences the adoption of sustainable farming practices are tested with data from a 1999 survey of 197 farms in the Peruvian Altiplano around Lake Titicaca. The survey used cluster sampling of farms in villages to represent each of three arable agro-ecological zones in the Ilave-Huenque river basin. Relative asset levels were used to stratify resident households within villages. Personal interviews collected a wide range of data on farm household assets, management practices, and status of agricultural natural resources.