Evaluation of Some Soil Health Parameters in Pasture-Based Beef Pastures in Southern Piedmont of Georgia.

Scientific assessment of soil health is important for monitoring sustainability of pasture-based cattle farming systems.  Three important indicators of soil health are potential N mineralization (Nmin), soil respiration (SR) and ammonia volatilization (AV).  Soil respiration reflects the degree of microbial activity in soil and its tendency to lose carbon in the form of CO₂, whereas, ammonia volatilization reflects the amount of nitrogen that is lost in the form of ammonia. Within a larger experiment which is assessing the effect of cattle management strategies (placement of shades, minerals, hay etc. in the field), this study is assessing soil respiration and ammonia volatilization from cattle camping areas within ten of the pastures and determining the relationship with real-time visible and near-infrared reflectance spectroscopy (RT-VNIR). The experiment is being conducted in ten pastures on two research farms owned by The University of Georgia (one in Watkinsville, GA and other in Eatonton, GA). Sealable, in-field chambers with two jar holders (one alkali-trap for measuring CO₂ evolved and an acid trap for measuring NH3 volatilized), were placed in cattle camping areas for 24 hours. Titration method was used to estimate the CO₂ adsorbed in the alkali-trap and NH₃ adsorbed in the acid-trap. Li-COR 6400 photosynthesis system was also used to measure soil temperature and CO₂ flux from the soil on the same day. Importance of soil and landscape parameters (soil moisture, temperature, taxonomy and landscape positions: concentrated flow area, elevation, aspect or shade) of cattle camping areas were also assessed to better understand influence of these parameters on soil N mineralization, ammonia volatilization and respiration from cattle camping areas. After completion of this research, we will be able to assess the difference in some soil health parameters, for cattle camping areas in the pastures.