We study how foreign demand for agricultural exports shapes technology adoption within the agricultural sector. Whereas modernization requires costly investment in capital and technology that primarily benefits crop cultivation, farmers may raise output instead by clearing forests to expand pasture. We study this choice during the commodity boom in Brazil, combining confidential records on the near universe of cross-bank electronic transfers with satellite imagery to observe land use and input purchases at the farm level. Using a shift-share shock, we find that foreign demand for agricultural exports causes farmers in the Amazon to reallocate land from capital-intensive soybean toward land-intensive pasture, reducing their purchases of machinery and technology as pasture replaces forest. We show that this response emerges optimally from the asymmetric use of land and technology across agricultural activities, since abundant land can cause farmers to specialize in pasture, reducing the area under crop cultivation needed to justify technology investments. We then embed this mechanism into a general equilibrium model with heterogeneous farmers, endogenous technology adoption, and credit frictions that hold adoption below its efficient level and show that a perfectly enforced no-deforestation tax of around US$700 per hectare can raise the welfare gains from trade by more than 75 percent.