Cover crop (CC) growth and biomass production in the Mid-Atlantic region can be limited following double crop soybean due slow establishment related cool fall temperatures. Interseeding CC in summer before soybean canopy closure can improve establishment and spring biomass production. This practice can also increase the diversity of available CC species, reduce weed pressure and reduce nutrient losses. This study evaluates the effects of interseeded CC on soil temperature, soil water balances, evapotranspiration, infiltration, and yield and water use efficiency of corn (Zea mays L.) phase, following soybean (Glycine max L.) The study was conducted at the USDA Beltsville Agricultural Research Center, Beltsville, MD from 2017 through 2020. The cropping systems under study were primarily sequences of corn-soybean-wheat (Triticum aestivum L.)-double crop soybean all planted with no-tillage management. No cover crops (NC) were grown prior to corn in Systems 3 and 4. In System 5, a cover crop (CC) mixture of rye (Secale cereale L.)-hairy vetch (Vicia villosa Roth)-crimson clover (Trifolium incarnatum L.) was interseeded into DCS prior to soybean canopy closure. In System 6, red clover (rc, Trifolium pratense L.) was interseeded into wheat in March and rye was planted into rc after wheat harvest in July.

Resources in this dataset:

• Resource Title: CCSP 2023 AGWAT Metadata
  File Name: CCSP 2023 AGWAT Metadata.docx
  Description: Meta information describing data collection procedures, estimation of ET and infiltration, and methods used to replace sensor data having errors.

• Resource Title: CCSP Experiment Setup Info Tables 1 Through 4
  File Name: CCSP Experiment Setup Info Tables 1 Through 4.xlsx
  Description: File contains data from Tables 1 through 4 of the manuscript and a schematic of the crop rotation; Table 1 describes the four cropping systems; Table 2 provides corn planting and harvest dates, cumulative growing degree days (CumGDD oC), rainfall, and period of soil water measurement for the growing season; Table 3 describes the soil water sensors and soil depths measured; and Table 4 gives 10 year average monthly air temperature and rainfall (2011 to 2020). Cover crop varieties are included in an additional worksheet. [Note: file updated to include cover crop varieties worksheet on 07/21/2023]

• Resource Title: CCSP Corn Yield Cover Crop Biomass
  File Name: CCSP Corn Yield Cover Crop Biomass.xlsx
  Description: Cover crop biomass (kg/ha) and corn yields (kg/ha) for 2017 through 2020 are provided at the replication and cropping system treatment level. Details about biomass sampling and corn harvest are contained in the manuscript.

• Resource Title: CCSP ET Calc Input Output Data And Meta Info
  File Name: CCSP ET Calc Input Output Data And Meta Info.xlsx
  Description: Weather data used to estimate daily evapotranspiration using ETCalc, an online calculator (Danielescu, 2021 and 2022) [ https://etcalc.hydrotools.tech/pageMain.php]. The input and output data are provided in separate tabs of the excel file. The first tab provides additional meta information.

• Resource Title: CCSP Weather 2017-2020 Rain And Air Temp For GDD
  File Name: CCSP Weather 2017-2020 Rain And Air Temp For GDD.xlsx
  Description: Daily data collected from a nearby weather station used to calculate 10-year average rainfall and temperature and used to calculate growing degree days in each growing season. Growing degree day calculations are presented in tabs for each year.

• Resource Title: CCSP Soil Temperature And Soil Water By Depth
  File Name: Volumetric soil water content (m3/m3) (VWC) and soil temperature data collected at 4 depths in each plot. VWC was converted to mm water per depth and summed for the soil profile (0 to 862 mm). Measurements were averaged to daily values. Soil water storage and soil temperature data are given for each replication, cropping system treatment, and horizon depth in separate tabs for each year.