DOI: 10.5061/dryad.6t1g1jx9r
title: Data from: Legacy effects of alfalfa monocultures or annual crop/alfalfa mixtures on subsequent corn yield and quality

description: Interseeding annual crops into existing alfalfa (Medicago
 sativa L.) stands is gaining interest, and one reason may be that
 alfalfa lowers nitrogen requirements for subsequent crops. However, little
 is known about the legacy impact of this practice on subsequent corn (Zea
 mays L.) production. An experiment involving interseeding annual
 cool‐season crops into alfalfa was conducted between 2017 and 2021, which
 serendipitously allowed us to evaluate the legacy impact of this practice
 on subsequent corn grain production. This follow‐up study compared corn
 grain yield and quality of corn planted subsequently on positive control
 plots (alfalfa monoculture), negative control plots (annual crop
 monoculture), and experimental treatment polyculture plots (annual crops
 planted into alfalfa). We found that corn yield was lower following annual
 monocultures compared to corn following alfalfa monoculture and
 polyculture plots. The treatments did not have a significant effect on
 grain protein or starch percentage, but grain oil percentage was higher
 following polyculture compared to annual monoculture. Corn grain zinc
 concentration was positively associated with previous alfalfa density and
 corn ear leaf chlorophyll concentration. These findings indicate that
 alfalfa monoculture and alfalfa‐annual crop polycultures can have
 different positive legacy effects on corn yield, near‐surface soil
 attributes, and grain quality. Future research aimed at evaluating the
 legacy of crop/alfalfa mixtures on subsequent corn crops in the northern
 Great Plains in multiple locations over several years are needed.
description: # Legacy effects of alfalfa monocultures or annual crop/alfalfa mixtures
 on subsequent corn yield and quality Dataset DOI:
 [10.5061/dryad.6t1g1jx9r](10.5061/dryad.6t1g1jx9r) ## Description of the
 data and file structure The data is associated with "Legacy effects
 of alfalfa monocultures or annual crop/alfalfa mixtures on subsequent corn
 yield and quality" published in Agrosystems, Geosciences &
 Environment.  Article DOI: 10.1002/agg2.70114. ### Files and variables
 #### File: AGE\_Whippo\_et\_al\_2025\_Data.xlsx **Description:** An excel
 work book with four tabs with data for plot soil analysis, plot alfalfa
 density, relative chlorophyll content, and grain yield and quality. #####
 Variables * plot = plot number * block = block or replicate number *
 2017_crop = Crop planted in 2017 * 2018_crop = Crop planted in 2018 * 2019
 crop = Crop planted in 2019 * 2020 crop = Crop planted in 2020 * 2021_crop
 = Crop planted in 2021 * 2022_crop = Crop planted in 2012 * treatment =
 plot treatment (alfalfa monoculture, alfalfa/annual mixture, or annual
 monoculture) * organic_matter_loi_percent = percent soil organic matter *
 soil_ph = soil pH * nitrate_n_ppm_n = soil nitrate ppm * sulfate_s_ppm_s =
 soil sulfate ppm * potassium_ppm_k = soil potassium ppm *
 mehlich_p_iii_ppm_p = soil mehlich p ppm * zinc_ppm_zn = soil zinc ppm *
 calcium_ppm_ca = soil calcium ppm * magnesium_ppm_mg = soil magnesium ppm
 * iron_ppm_fe = soil iron ppm * sodium_ppm_na = soil sodium ppm *
 mangansese_ppm_mn = soil manganese ppm * cec_sum_of_cations_me_100g = soil
 cation exchange capacity * alfalfa_density_plants_m^-2 = density of
 alfalfa plants (plants per meter square) * relative_chlorophyll = ear leaf
 relative chlorophyll content * yield_kg_ha = corn grain yield (kilograms
 per hectare) * dry_basis_protein_percent = corn grain protein percentage *
 dry_basis_starch_percent = corn grain starch percentage *
 dry_basis_oil_percent = corn grain oil percentage * P_mg_m = corn grain
 phosphorous concentration (milligrams per gram) * S_mg_g = corn grain
 sulfur concentration (milligrams per gram) * K_mg_g = corn grain potassium
 concentration (milligrams per gram) * Mg_mg_g = corn grain magnesium
 concentration (milligrams per gram) * Fe_ug_g = corn grain iron
 concentration (micrograms per gram) * Zn_ug_g = corn grain zinc
 concentration (micrograms per gram)