Data from: Patterns of water-extractable soil organic matter in the US Great Plains: Insights from the Haas Soil Archive

Carbon (C) and nitrogen (N) extracted from soil with water are associated with available plant nutrients and microbial activity but information about how they have changed over time in the U.S Great Plains is sparse. We used cool (20 oC) and hot (80 oC) water extracts from historic (1947) and current (2018) soil samples collected at Moccasin, MT, Akron, CO, and Big Spring, TX to evaluate changes to extractable C and N and optical properties after 71 years of dryland cropping. Together, water extracts and optical methods can produce insights into long-term changes in labile soil organic matter while conserving physical samples of archived soil.