Causal Misperception and Persistent Fertilizer Overuse in China

While under-adoption of technology in agriculture is widely discussed, the inappropriate use of technology/input has become a matter of concern. We find strong evidence that farmers in China tend to overuse nitrogen fertilizer and underuse fertilizers in other dimensions, including phosphorus and potassium. Such decision making is affected by the crops' growing stages before the ripening, in which nitrogen provides observable signals on plants while phosphorus and potassium do not. We propose two randomized controlled trials to examine the effects of noticing/improved learning on the appropriate adoption of fertilizers. Our interventions consist in providing soil testing information, fertilizer recommendations, and technologies to facility farmer's learning.