Soil organic carbon accumulation in restored native prairies over time

With the recent focus on the causes and effects of climate change, the relationship between agriculture and climate change has become an important concern. Conventional farming maximizes crop production at the expense of ecosystem services like soil carbon storage. As the human population grows, it is vital to develop practices that balance crop production and ecosystem services. We investigated organic carbon accumulation in restored prairie soil over the course of a decade. Our goal was to determine how organic carbon levels and soil bulk density changed over time, and how that change was influenced by species diversity and soil depth. We hypothesized that more organic carbon would be stored in soil over time, and bulk density would decrease, both of which we found to be true. We also hypothesized that the amount of organic carbon stored would increase with greater species diversity (1-species, and 5-, 16-, and 32-species mixes) and it would decrease with soil depth. Our results showed us that species diversity has no noticeable effect on organic carbon levels, with the 5-species mix being the exception, as it stored very low levels of organic carbon. In both soil depths (0-7.5 cm and 7.5-15.0 cm), bulk density increased the first 5 years, then decreased drastically over the next 6 years, but when we compared 0-7.5 cm and 7.5-15.0 cm depths with each other, we found an overall decrease in the upper layer. We concluded that organic carbon accumulation increases over time in restored prairie soil regardless of species diversity or soil depth. As time passed, growing roots loosened up the soil, increasing and then decreasing bulk densit