DOI: 10.5061/dryad.xksn02vn6
title: No yield benefit from starter fertilizer in soybean no-till planted into rolled-crimped cereal rye

description: No-till planting organic soybean (Glycine max [L.] Merr.) into
 rolled-crimped cereal rye (Secale cereale L.) can improve soil health
 while decreasing labor and fuel costs but yield declines from
 tillage-based production hinder wider adoption. In addition to soil
 moisture depletion, nitrogen (N) tie-up in cereal rye biomass and cool
 soil temperatures under mulches may contribute to yield differences by
 decreasing N availability early in the production system before the onset
 of biological N fixation. A field experiment was conducted to determine if
 starter fertilizers could increase early-season soybean growth and
 subsequent yields. Over five site-years in New York and Wisconsin on
 organically managed land, soybeans were no-till planted into
 rolled-crimped cereal rye and four treatments were applied in a randomized
 complete block design: feather meal (FM), poultry litter (PL), and sodium
 nitrate (SN) starter fertilizer treatments supplied at 28 kg N ha-1 and a
 zero fertilizer control. Early-season growth, weed biomass, soybean
 biomass, soybean density, and soybean yield were compared among
 treatments. The relationships between soybean yield and these other
 variables were also explored. Some differences among treatments were
 observed in early-season growth, but the results were inconsistent and
 only found in two site-years. Soybean yield did not differ between the
 control (2664 kg ha-1) and any treatment (FM: 2760, PL: 2812, and SN: 2769
 kg ha-1), though greater cereal rye biomass and soybean density were
 associated with higher yield. The results suggest that soybeans in organic
 cover crop-based no-till production do not consistently respond to starter
 fertilizer.
description: # No yield benefit from starter fertilizer in soybean no-till planted into
 rolled-crimped cereal rye
 [https://doi.org/10.5061/dryad.xksn02vn6](https://doi.org/10.5061/dryad.xksn02vn6) This dataset contains all response variables collected over five site-years to assess the effects of starter nitrogen fertilizer on soybeans no-till planted into a rolled-crimped cereal rye cover crop mulch. Weed biomass, growth stage at 6-weeks post-planting, soybean density at harvest, and soybean yield were collected in all site-years at the plot level. Soybean biomass was collected at the plot level in every site-year except New York 2020. Soybean height, soybean growth stage, and leaf greenness as measured with a SPAD meter were collected over four weeks in two of the site-years to assess early-season growth responses of soybean to starter fertilizer. Cereal rye biomass after termination and soil variables (pH, soil P, soil K, and soil organic matter) were collected at the block level in each site-year. ## Description of the data and file structure This dataset contains three CSV files. The names and explanation of columns in each are provided below. **AllenEtal.StarterN.allplots.csv** contains all variables collected at the plot-level in every site-year. * siteyr (factor) the site-year code [NY20 = New York 2020, NY21 = New York 2021, NY22 = New York 2022, WI21 = Wisconsin 2021, WI22 = Wisconsin 2022] * block (factor) the block number [1, 2, 3, 4, 5] * treatment (factor) the starter fertilizer treatment applied to the plot [PL = poultry litter, CT = control (no fertilizer), FM = feather meal, SN = sodium nitrate] * weed.bm.kgha (numeric) dry weed biomass in kg/ha *NOTE: this variable was log(x+1) transformed to meet modeling assumptions* * soy.stand.ha (numeric) soybean density at harvest in plants/ha * soy.bm.kgha (numeric) dry soybean biomass in kg/ha, sampled with weed biomass at the R6 soybean growth stage * yield.kgha (numeric) soybean yield in kg/ha adjusted to 13% moisture * avg.gs.6wk (numeric) average soybean growth stage six weeks after planting (average of 10 plants per plot). *NOTE: Growth stage was converted to an ordinal quantitative variable by assigning integers to ascending growth stages (VE = 0, VC = 1, V1 = 2, … R3 = 10)* **AllenEtal.StarterN.SPAD\_height\_gs.csv** contains variables collected in two site-years (New York 2021 and Wisconsin 2021) to assess early growth responses to starter fertilizer. All variables were measured on 5 plants per plot per week and numbers presented in the CSV are averaged at the plot level for each week. * siteyr (factor) the site-year code [NY20 = New York 2020, NY21 = New York 2021, NY22 = New York 2022, WI21 = Wisconsin 2021, WI22 = Wisconsin 2022] * week (factor) the week of sampling, in weeks post-planting [4, 5, 6, 7] * block (factor) the block number [1, 2, 3, 4, 5] * treatment (factor) the starter fertilizer treatment applied to the plot [PL = poultry litter, CT = control (no fertilizer), FM = feather meal, SN = sodium nitrate] * gs\_num (numeric) average growth stage of the sampled plants in a given week. *NOTE: Growth stage was converted to an ordinal quantitative variable by assigning integers to ascending growth stages (VE = 0, VC = 1, V1 = 2, … R3 = 10)* * gs\_cat (factor) mode of the growth stage of the sampled plants in a given week (not used for analysis) * height (numeric) average height of the sampled plants in centimeters in a given week * spad (numeric) average SPAD meter reading of the sampled plants in a given week **AllenEtal.StarterN.blocklevel.csv** contains only variables collected at the block level in each site-year, including cereal rye biomass and soil variables. * siteyr (factor) the site-year code [NY20 = New York 2020, NY21 = New York 2021, NY22 = New York 2022, WI21 = Wisconsin 2021, WI22 = Wisconsin 2022] * Ryebm (numeric) dry cereal rye biomass after termination in kg/ha * Soil\_P (numeric) Morgan soil phosphorus in kg/ha * Soil\_K (numeric) Morgan soil potassium in kg/ha * SOM (numeric) soil organic matter percentage (converted to g/kg in the publication) * Soil\_pH (numeric) soil pH