As of September 2016, the Century Experiment online database is undergoing maintenance. Most data are available by contacting ASI directly. 

Available data may include, but are not limited to, soil properties (carbon, nitrogen, ammonium, nitrate, potassium, phosphorus, and sulfur; bulk density; organic matter; hydraulic properties, particle size distribution and texture); compost analyses; harvest data (yield for corn, alfalfa, wheat, tomato, sudangrass, and cover crops); operations data (planting dates, pesticide applications, fertilizer applications, harvest information); weather data; weed data (species, counts, density); imagery data (NDVI); and water analyses.

We are working to migrate the database to a new, more user-friendly platform. Please contact ASI with any questions. Thank you.