In 2019, vast expanses of South Dakota were flooded. Many South Dakota producers are now left with the challenge of planting fields that were left fallow in 2019. Producers on the South Dakota Soil Health Coalition (SDSHC) Board state that they were able to access their no-till fields when neighboring conventional tillage fields were inaccessible. No-till management systems can protect our agricultural lands from flood, as well as drought, through increased soil organic matter and water holding capacity. Unfortunately, as severe weather events increase in frequency and decrease in predictability, many no-till acres risk being returned to tillage due to negative perceptions of increased management challenges and reduced yield.
Lake Area Technical Institute (LATI) in Watertown, South Dakota, operates a long-term, no-till demonstration farm north of their campus. The demonstration farm has been under no-till management for more than 20 years. Due to interest from area producers, strips of the farm have been returned to tillage in anticipation of yield gains. Initial plans by LATI for this experiment were to monitor yield only. Upon suggestion from South Dakota State University (SDSU) researchers and the SDSHC, baseline soil samples were collected prior to implementing the tillage treatments for comparison at the end of the three-year trial. However, there is high learning potential from collecting annual soil samples as is proposed here. For example, soil organic carbon changes may not be static from year to year and an opportunity exists to determine equilibrium rate constants using data from time zero, the baseline. The proposed SARE project would monitor changes in soil physical, chemical, and biological properties caused by tillage through aggregate stability, bulk density, soil chemical properties, and phospholipid fatty acid analysis (PLFA) annually for three years.
Learning outcomes include that area producers will witness the detrimental impacts of tillage on soil health parameters and insignificant increases in yield. Action outcomes include that area producers will use this information to determine if tillage is worth detrimental impacts on soil health parameters. Project summaries will be presented at two annual LATI producer field days, shared with SDSU Extension, the SDSHC, and with local Natural Resources Conservation Service (NRCS) offices. A publication will be submitted to a journal, such as Soil and Tillage Research, for peer-review.
Project objectives from proposal:
Our hypothesis would include outcomes showing that, over the course of three years, there will not be significant yield increases in the tillage treatments compared to the no-till. However, significant improvements in soil physical, chemical, and biological properties in the no-till treatment compared to the tillage treatments will be observed. The primary learning outcome of this research will be utilization of quantitative data to inform producers on the negative effects of tillage on soil health properties. Coupling quantitative soil property data with yield and economic data, ample information will be available for area producers who are contemplating which management system would be best for their operation. Learning outcomes from this project will lead to the primary action item of producers opting to maintain their existing no-till systems, or convert to no-till management systems.