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Executive Summary Report
Maximizing Soil Warming and Health under Different Tillage Practices in a Corn-Soybean Rotation
Dr. Aaron Daigh, NDSU Soil Science Dept., Principle Investigator
Jodi DeJong-Hughes, UMN Extension,
Dr. Abbey Wick, NDSU Soil Science Dept.
There are many advantages of reducing soil tillage for building soil health. However, reducing tillage creates concerns of yield reductions due to cool and wet soils in the poorly-drained landscape that dominates much of North Dakota and the Red River Valley. The objectives of this study are to:
1. monitor soil warming and water contents under chisel plow, vertical tillage, strip till with shank, and strip till with coulter on various soil series
2. evaluate soil health and crop emergence and yields, and
3. transfer information to producers through field days, videos, etc.
This is a multi-state effort, involving North Dakota and Minnesota and is in year three of a six year field study. Four on-farm locations are under a corn-soybean rotation and rotate each year. At each location, the four tillage practices are demonstrated using full-sized equipment in plots of 40 or 66 feet wide by 1800 feet long in a replicated design. Soil series evaluated are Fargo silty clay, Lakepark clay loam, Barnes-Buse loams, Delamere fine sandy loam, and Wyndmere fine sandy loam. These soils cover over 67 million acres of farmland in the Northern Great Plains regions.
Soybean yields in 2015 and 2016 did not significantly differ among tillage. Soil temperatures and water contents differed among tillage treatments briefly in the spring of 2016 but then converged together during the following cool, dry weeks through planting. Later in the summer and fall months, soil temperatures were highest and water contents lowest in the strip till berms and chisel plowed plots as compared to the vertical till and undisturbed areas between the strip till berms. These differences among tillage treatments were largest in the sandy loam soils but rarely observed in the silt clay soils. In spring of 2016, crop residue cover differed among tillage, however, stand counts and plant heights did not differ among tillage treatments at any of the farms.
Soil samples have been collected to determine biological communities and activities and are being analyzed. These analyses will continue throughout 2017 to determine biological shifts over time among tillage systems. Residue cover, crop populations, and yields will be evaluated in 2017. This project has was produced three videos and disseminated information at 31 field days, presentations, and other university events to deliver study findings to North Dakota producers; video’s viewed 7,000 times from around the world. Information obtained during this year will be presented at joint NDSU and UMN Extension events including field days, bus tours, the 2017 Conservation Tillage Conference as well as at the joint International America Society of Agronomy, Soil Science Society of America, and Crop Science Society of America Conference in Tampa, FL in November, 2017. Four tillage videos are in production and will be completed and released by the end of 2017.