Soil Quality: Using Cover Crops to Improve Soil Health and Moisture Retention.

Soil health is not only a way to define the soil condition but can be used to motivate and educate farmers on management practices that optimize their soil resource.  However, critical questions about both the biological and physical components of soil and how the interplay impacts soil health remain unanswered.  Our efforts have assessed the physical, chemical and biological characteristics of soils in fields planted to cover crops and how these factors affect abiotic and biotic parameters. Analysis has include a wide range of standard chemical and physical measures, which have been enhanced by looking at microbial biodiversity, and in-field measurement of CO₂, N₂O, CH₄ flux and changes in soil temperature and moisture responses (i.e., soil carbon soil moisture retention and biodiversity.)  We have repeatedly sampled fields with a cover crop history, in the early fall, prior to cover crop, winter to early spring under cover crop, in spring prior to burn down of cover crop and in the subsequent crop and these sites are contrasted to fields not planted with cover crops.  Using discriminant analysis, our results show a number of differences in how soil response following the use of cover crops.  Most notable is our finding is that sites with cover-crops have lower flux rates for methane and nitrous oxide than the no-cover crop fields while CO₂ flux is the same for both systems.  Our ongoing work shows the role of cover crops in effecting soil moisture retention is confounded by soil type and that soil biodiversity may also be impacted by cover crops.