Impacts of Cover Crop and Grazing Management Under Integrated Crop Livestock System on Soil Microbial Parameters.

Oral Presentation at the MANAGING GLOBAL RESOURCES FOR A SECURE FUTURE

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

Section: Land Management and Conservation   Impacts of Cover Crop and Grazing Management Under Integrated Crop Livestock System on Soil Microbial Parameters

Vishal Seth^a, Michael Lehman^b and Sandeep Kumar^a

^aSouth Dakota State University, Department of Agronomy, Horticulture and Plant Science, Brookings, SD,57007, USA.

^bUSDA-ARS, Brookings, SD

Presenter: Vishal Seth (vishal.seth@sdstate.edu )

Oral Presentation Abstract

ABSTRACT

Diversification of the existing cropping system and increasing the multiple and temporal use of land may have the potential for the sustainable production by integrating crop livestock (ICL) system.  The objective of this study was to explore the short-term impacts of cover crops and grazing on soil physio-hydrological, microbial and enzymatic properties in South Dakota. The experiment was started in the year 2016 at South Dakota State University research farm in Brookings, South Dakota, USA. The experimental design was Randomized Complete Block Design with 4 replications. Cover crops blends (grass leaf cover crop and broad leaf cover crops), grazing, and control treatments were used. The soil sample was taken three times: pre-grazing (August 2016), post-grazing (November 2016), and before planting (June 2017). The results of post grazed soil sample showed that the soil microbial biomass carbon was higher and soil nitrogen was lower as compared to the pre-grazed soil, which directly showed that the number of soil microbes increases after grazing. In carbon and nitrogen fractions, crop rotation and grazing and their interaction have no significant impact on inert, labile and recalcitrant carbon, but time had a significant impact on them at 0-5 cm depth, and labile nitrogen was significantly higher in grass leaf cover crops as compared to broad leaf cover crops. Soil Urease activity was significantly increased in post grazed soil only at 0-5 cm depth. The results indicate that the rotation and grazing do not significantly impact the different forms of carbon and the urease activity in short term analysis, and time is a key factor in significantly impacting all parameters at 0-5 cm depths. β-glucosidase was found to decrease after the grazing which shows organic matter decomposition decreases after grazing due to increase in soil microbes consumption of sugars(glucose).