Impacts of Integrated Crop-Livestock System on Soil Surface Greenhouse Gases in South Dakota.

Oral Presentation at the MANAGING GLOBAL RESOURCES FOR A SECURE FUTURE

2017 Annual Meeting | October 22-25 | Tampa, FL

Division: Environmental Quality Title: Greenhouse Gas Emissions from Integrated-Crop Livestock System Poster (includes student competition)

  

Impacts of Integrated Crop-Livestock System on Soil Surface Greenhouse Gases in South Dakota

Navdeep Singh, Liming Lai, Juan D. Pérez-Gutiérrez, and Sandeep Kumar

Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, South Dakota 57007, USA

Presenter: Navdeep Singh (Navdeep.Singh@sdstate.edu)

Oral Presentation Abstract

ABSTRACT

Intensification of crops and livestock production have caused soil and air pollution. Integrated crop-livestock (ICL) systems are considered one of the several alternatives that can alleviate this problem. In particular, the benefits of ICL systems on reduction of soil surface greenhouse gas (GHG; carbon dioxides - CO₂, methane - CH₄, and nitrous oxide - N₂O) emissions have been poorly understood, especially in South Dakota (SD). Therefore, the goal of this study was to evaluate the impacts of ICL systems on soil surface GHG fluxes at an experimental research farm located in Brookings, SD. The experimental site was divided into 20 plots, under a randomized complete block design (five treatments) with four replications. The treatments included the control (corn-soybean-oat), two different cover crop rotations (corn-soybean-oat/broadleaf; corn-soybean-oat/grass), and two different cover crop rotations with grazing (corn-soybean-oat/broadleaf - grazing; corn-soybean-oat/grass - grazing). The GHG sample collection occurred every week at three-time intervals (0, 20, 40 minutes) from each individual plot during the growing season in 2016 using the static chamber method. Samples were analyzed for concentration of CO₂, CH₄, and N₂O using a Gas Chromatograph. Chamber temperature and soil moisture and temperature from the 0-10 cm depth were also measured for each chamber. Preliminary results showed that the crop rotation did not significantly impact the N₂O fluxes while grazing did impact these fluxes. The grazed period had significantly higher N₂O fluxes than the ungrazed period. However, neither rotation nor grazing impacted CO₂ and CH₄ fluxes. The time significantly impacted soil surface N₂O and CO₂ fluxes but not CH₄ fluxes.