Excess nutrients from land-applied animal manures can leach through the soil and potentially contaminate ground water. To assist in determining appropriate application rates of manure, a field study was conducted to determine N mineralization rates of poultry litter in two southeastern Coastal Plain soils. The overall objective of the project was to determine the influence of moisture, temperature and soil type on N mineralization rates. The study consisted of 96 microplot cylinders, manure amended and unamended, destructively sampled at predetermined intervals. Each 8 cm x 15 cm PVC cylinder contained a minimally disturbed soil core with poultry litter incorporated into the top 4 cm of the soil. The objective of this component of the research was to measure any effects of the microplot cylinders on temperature and moisture so that the impact of the cylinders could be weighed into the results of the study. Eight additional microplot cylinders were instrumented to continuously measure soil temperature and water content. An additional set of soil temperature and water content sensors was placed directly into the soil to measure soil conditions outside the cylinders. Soil temperature was measured with type-T thermocouples and soil water content was measured with gypsum blocks. In 2004, the study was conducted on a Tifton loamy sand (fine-loamy, siliceous, thermic Plinthic Paleudult), and in 2005, on a Greenville fine sandy loam (fine, kaolinitic, thermic Rhodic Kandiudult). Particularly in the coarser textured Tifton soil, during drying conditions, water potential was greater outside the cylinders than inside the cylinders. Neither soil exhibited clear differences in soil temperature inside the cylinders versus outside the cylinders. Overall, soil temperature and soil moisture conditions inside the microplot cylinders were found to be representative of the conditions outside the cylinders.