This project looks at the impact of soil compaction on corn emergence, growth and development, and yield. This is a two-year study, begun in the in the spring of 2013, it will be completed after the 2014 growing season. Corn was produced in the field both years.
The project hypotheses are to: 1) Soil compaction does impact corn growth, development and yield; 2) Soil compacted in the fall season by farm equipment is measurable the following spring, and may impact crop yield the following season.
The objectives are to: 1) Evaluate the impact of soil compaction on corn emergence, plant development, and yield; 2) Evaluate the effect of the winter freezing-thawing cycle on soil compaction.
This presentation will report results from the first year of the study, and beginning data from the second year of the study.
To compare the impact of soil compaction on corn emergence, plant development, and yield, investigators installed soil moisture, temperature and rainfall sensors in the field to remotely monitoring soil temperature and moisture content. This data is displayed live on the Internet, and updated daily.
The field is divided into three replicated strip plots. Investigators marked five transects across the three replications corresponding to the five soil types in the study area. They collected soil cores from surface to 12 inch depth to measure soil bulk density, and recorded soil moisture content at each sample location. Soil compaction readings were taken at three locations within each plot, prior to planting, after planting with 16-row planter. Sol samples and compaction readings were taken two rows where there was no effect of compaction, and in two rows that were compacted from the tractor tires, planter tires and fertilizer cart tire.
During the summer of 2013 after chemical application investigators recorded soil compaction readings at three locations within each plot where there was no compaction from tires, and three locations where there was compaction from tires. At crop emergence, plant population count at samples were taken at locations in non-compacted and compacted corn rows. Investigators measured and monitor plant height and biomass at tasseling, also in the non-compacted and compacted corn rows. They again measured and monitored plant height and biomass prior to harvesting in the same locations.
At the fall 2013 harvest, investigators again measured biomass and yield using hand harvesting methods, in the non-compacted and compacted corn rows. Yield was also measured with the combine yield monitor.
After the fall 2013 harvest investigators recorded soil compaction readings at three locations within each plot: 1) In the combine tracks; 2) in grain cart tracks; and 3) five feet from any combine or grain cart tracks.
Investigators made statistical comparisons compare yield between rows next to wheel tracks with rows away from tracks. They compared of soil resistance and bulk density under track-traffic rows against rows not subjected to such traffic. They used a statistical mean analysis to help determine whether tire/track traffic causes soil compaction in local soils.
Each of the experiments will be repeated for two years in the same field.
The data from the first objective of this experiment is also being used to evaluate the effect of the winter freezing and thawing on soil compaction. Investigators performed a statistical comparison of compaction data collected from adjacent areas along tire/track trafficked areas after harvest, and at spring, to show the effect of winter freezing and thawing cycles on compaction.
