DOI: 10.7302/z2k072fc
title: Crop rotations for increased soil carbon: perenniality as a guiding principle

description: This dataset contains three data files used in: King, A.E. and J. Blesh, 2017. Crop rotations for increased soil carbon: perenniality as a guiding principle. Ecological Applications. There are also three corresponding metadata files.

The file “CRMA 2017 Main.csv” contains data for the control and treatment rotations used to construct pairwise comparisons for meta-analysis, response ratios calculated for soil organic carbon concentration, and change in carbon input. The dataset also includes management, soil, and other environmental characteristics for each site.  

The file “CRMA 2017 Diversity x Nitrogen.csv” contains data used to test whether N fertilizer inputs mediated the effect of functional diversity on SOC concentrations. 

The file “CRMA Annual grain.csv” contains data used to test for effects of crop rotation species diversity (one vs. two species, or two vs. three species) on SOC concentrations and C input (i.e., for the “grain-only” rotations). The dataset also includes management, soil, and other environmental characteristics for each site.  

The corresponding metadata files: “CRMA 2017 Main_metadata.csv”, “CRMA 2017 Diversity x Nitrogen_metadata.csv”, and “CRMA Annual grain _metadata.csv” provide a detailed description of all variables in each dataset. 

Note: On Jan 12, 2018 the following information was added to the three metadata files: the name of the data file the metadata refers to, an explanation as to the meaning of blank cells in the data file, a full citation to the paper where the author describes her findings and contact information for the author.

description: We performed a search of Web of Science [v.5.16] on October 28, 2014 using the search terms (crop* rotation OR crop* system OR agroecosystem) AND (soil carbon OR soil organic matter) AND (long-term OR field) NOT (greenhouse OR pot), which returned 563 hits. Criteria for inclusion were at least two levels of crop species diversity (e.g., 1 and 2 species, or 2 and 4 species), or at least two levels of functional group diversity (e.g., cereals and cereals + perennial crop). All crop rotations included at least one grain crop
description: agroforestry and pasture systems were beyond the scope of this study. Forty-nine publications, representing 27 cropping system sites, met criteria for inclusion in the study. To create crop rotation typologies based on functional diversity of crops, we first assigned each crop to a functional type: 1) grass or legume, 2) annual or perennial, and 3) harvested or non-harvested (cover crop). Using the above groups for individual crops, we created several typologies of crop rotations between which to construct pair-wise comparisons within sites. For a given pair-wise comparison, the control rotation had lower functional group richness than the treatment rotation. The database includes 167 crop rotations. As response variables, we recorded SOC on a concentration (g C kg-1 soil) and an areal (Mg C ha-1) basis and calculated an effect size using the response ratio of treatment to control (r = SOCt / SOCc). We log transformed response ratios (R = ln(r) = ln(SOCt) – ln(SOCc)) to perform the meta-analysis on normally distributed data. Full details of the methods can be found in: King, A.E. and J. Blesh, 2017. Crop rotations for increased soil carbon: perenniality as a guiding principle. Ecological Applications.