Soil carbon maintained by perennial grasslands over 30 years but lost in field crop systems in a temperate Mollisol

To mitigate climate change, some seek to store carbon from the atmosphere in agricultural soils. However, our understanding about how agriculture affects soil organic carbon is muddied by studies (1) lacking longitudinal data, (2) ignoring bulk density changes, or (3) sampling only surface soils. To better understand soil organic carbon trends, here we measured changes over 30 years in density-corrected, full-soil-depth (90 cm) soil organic carbon stocks under 6 cropping systems and a restored prairie in a Mollisol of southern Wisconsin, USA. Cash-grain systems and alfalfa-based systems lost soil organic carbon. Prairie and rotationally-grazed pasture maintained soil organic carbon. Average soil organic carbon losses for cash-grain and alfalfa-based systems were −0.82 (±0.12) and −0.64 (±0.17) Mg C ha-1 yr-1, respectively. Sensitivity analysis showed that incomplete methodologies overestimated soil organic carbon improvements. Our findings using more comprehensive methods demonstrate th..., , , # Soil carbon maintained by perennial grasslands over 30 years but lost in field crop systems in a temperate Mollisol

[https://doi.org/10.5061/dryad.b8gtht7mv](https://doi.org/10.5061/dryad.b8gtht7mv)

This dataset contains percent carbon, percent nitrogen, and soil bulk density data for samples from the Wisconsin Integrated Cropping Systems Trial (WICST) collected in 1989, 2009, and 2019. WICST compares six cropping systems and a restored native grassland common to the Upper Midwest United States of America in a randomized complete block design. This data was collected to measure changes in soil organic carbon stocks over time as a result of different cropping systems and land use.

## Description of the data and file structure

This data is available as an Excel spreadsheet and associated Microsoft Word document. In these, there is a full description of the experiment and data.

## Code/Software

SAS code used to analyze the data using a linear mixed effects model is available in the...