<p>Cover crop use, especially
in no-till systems, is an evolving practice to maintain or improve soil health.
There are many possible indicators of soil health, but this study focuses on
the analysis of soil aggregate stability, soil active carbon, and soil organic
matter. Soil aggregate stability is related to water infiltration and potential
for soil erosion, while active carbon serves as an indicator of a
readily-available food source for microbial activity, and soil organic matter
serves as a mediator for the soil physical, chemical, and biological processes.
The sites include: three Purdue Agricultural Centers, two
soil and water conservation district sites, 12 farmer sites with conservation
cropping systems, and seven conventional comparison sites. The treatments
consisted of cover crop versus no cover crop use, or cover crop use with different
tillage systems or nitrogen rates. In 2016 and 2017, soil samples were collected at a depth of 0-5 cm, air-dried, and
separated into two soil size fractions: 0-2 mm and 2-8 mm. The wet sieve method
was used to measure the mean weight diameter of the water stable soil
aggregates from the 2-8 mm size fraction in both years. The potassium permanganate
method was used to measure the soil active carbon from both size fractions in both years. The dry combustion method was used to
measure the soil organic matter from both soil size fractions in 2017 only. Results showed relatively
small improvements in soil active carbon and aggregate stability with the
addition of three to four years of cover crops to the long-term no-till
systems. However, these improvements were greater when comparing the cover
crops plus no-till treatments to the conventional-till without cover crops. More work is needed to understand the dynamics of soil aggregate
stability, soil active carbon, and soil organic matter in relation to soil
health and cover crop use. Cover crops will likely have more impact on soil aggregate stability, active carbon, and organic matter with a longer
duration of use.</p><p></p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/7427762 |
| Date | 17 January 2019 |
| Creators | Nicole A. Benally (5930540) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/Soil_aggregation_and_soil_carbon_measurements_to_assess_cover_crop_improvements_to_soil_health_in_Indiana/7427762 |
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