The LDMI experiment (Low-Disturbance Manure Incorporation) was designed to evaluate nutrient losses with conventional and improved liquid dairy manure management practices in a corn silage (Zea mays) / rye cover-crop (Secale cereale) system. The improved manure management treatments were designed to incorporate manure while maintaining crop residue for erosion control. Field observations included greenhouse gas (GHG) fluxes from soil, soil nutrient concentrations, crop growth and harvest biomass and nutrient content, as well as monitoring of soil physical and chemical properties. Observations from LDMI have been used for parameterization and validation of computer simulation models of GHG emissions from dairy farms (Gaillard et al., submitted). The LDMI experiment was performed as part of the Dairy CAP, described below.

The experiment included ten different treatments: (1) broadcast manure with disk-harrow incorporation, (2) broadcast manure with no tillage incorporation, (3) manure application with “strip-tillage” which was sweep injection ridged with paired disks, (4) aerator band manure application, (5) low-disturbance sweep injection of manure, (6) Coulter injection of manure with sweep tillage, (7) no manure with urea to supply 60 lb N/acre (67 kg N/ha), (8) no manure with urea to supply 120 lb N/acre (135 kg N/ha), (9) no manure with urea to supply 180 lb N/acre (202 kg N/ha), (10) no manure / no fertilizer control. Manure was applied in the fall; fertilizer was applied in the spring. These ten treatments were replicated four times in a randomized complete block design.

The LDMI experiment was conducted at the Marshfield Research Station of the University of Wisconsin and the USDA Agricultural Research Service (ARS) in Stratford, WI (Marathon County, Latitude 44.7627, Longitude -90.0938). Soils at the research station are from the Withee soil series, fine-loamy, mixed, superactive, frigid Aquic Glossudalf. Each experimental plot was approximately 70 square meters. A weather station was located at the south edge of field site. A secondary weather station (MARS South), for snow and snow water equivalence data and for backup of the main weather station, was located at Latitude 44.641445 and Longitude -90.133526 (16,093 meters southwest of the field site).

The experiment was initiated on November 28, 2011 with fall tillage and manure application in each plot according to its treatment type. Each spring, corn silage was planted in rows at a rate of 87500 plants per hectare. The cultivar was Pioneer P8906HR. The LDMI experiment ended on November 30, 2015.

The manure applied in this experiment was from the dairy herd at the Marshfield Research Station. Cows were fed a diet of 48% dry matter, 17.45% protein, and 72.8% total digestible nutrients. Liquid slurry manure, including feces, urine, and rain, was collected and stored in a lagoon on the site. Manure was withdrawn from the lagoon, spread on the plots and sampled for analysis all on the same day, once per year. Manure samples were analyzed at the University of Wisconsin Soil and Forage Lab in Marshfield (NH4-N, total P and total K) and at the Marshfield ARS (pH, dry matter, volatile solids, total N and total C).

GHG fluxes from soil (CO2, CH4, N2O) were measured using static chambers as described in Parkin and Venterea (2010). Measurements were made with the chambers placed across the rows of corn. I Additional soil chemical and physical characteristics were measured as noted in the data dictionary and other metadata of the LDMI data set, included here.

This experiment was part of “Climate Change Mitigation and Adaptation in Dairy Production Systems of the Great Lakes Region,” also known as the Dairy Coordinated Agricultural Project (Dairy CAP), funded by the United States Department of Agriculture - National Institute of Food and Agriculture (award number 2013-68002-20525). The main goal of the Dairy CAP was to improve understanding of the magnitudes and controlling factors over GHG emissions from dairy production in the Great Lakes region. Using this knowledge, the Dairy CAP has improved life cycle analysis (LCA) of GHG production by Great Lakes dairy farms, developing farm management tools, and conducting extension, education and outreach activities.