This study was undertaken as part of the National Soil Survey Center's Soil Biology Program. This project is a cooperative effort of the USDA Natural Resource Conservation Service Soil Survey Program, the Pennsylvania NRCS Soil Survey Staff, the Big Flats Plant Materials Center, and the USDA Agricultural Research Service. A primary objective of the program is to evaluate and measure soil biological characteristics related to the amount and turnover rate of organic matter of the three organic matter pools found in soils: fast pool, intermediate pool, and slow pool. The objective of this particular study is to evaluate the difference in soil organic matter, carbon, microbial biomass and soil physical properties resulting from the use of fall-seeded cover crops and conventional verses no-tillage silage corn systems. Six different farm management systems were examined: 1) conventional tillage, no cover crop (Conv/no-cc); 2 ) no tillage, no cover crop (No-till/no-cc); 3)conventional tillage with cover crop (Conv/cc); 4) no-tillage, with cover crop (No-till/cc); 5) alfalfa/grass hay rotation, conventional tillage (Conv/Alf-hay); and 6) alfalfa/grass hay rotation, no-tillage (No-till/Alf-hay). The soils were Hagerstown silt loams and the similar Hublersburg silt loams, both are fine-textured, mesic, Hapludalfs and Hapludults respectively. Treatment sites were sampled over two consecutive years. Soils from each treatment were sampled at 0-5 cm, 5-10 cm, and the top 5 cm of the B horizon. Soil analyses included: organic carbon; soil carbon to nitrogen ratios related to the composition of plant and microbial communities; microbial biomass and activity, two labile carbon fractions, and potential mineralizable nitrogen from microbial activity for the fast pool; root biomass and particulate organic matter (POM >53 microns) for the intermediate pool; and clay associated amorphous organic matter (C-Min <53 microns) for the slow pool. Preliminary analyses of the first year's data suggest that the No-till/cc treatments had the greatest amount of microbial biomass (kg/ha) and the greatest amount of nitrogen (kg/Ha) in both the POM fraction and the C-Min fraction implying that the No-till/cc treatments resulted in the greatest amount of fast pool carbon. Among the two alfalfa-hay treatments, the no-till soil had more fast pool carbon as measured by greater microbial biomass, and greater nitrogen (kg/ha) in the POM; but it had less nitrogen in the C-Min fraction. Data from the No-till/no-cc site was problematic as the field turned out to have supported a winter cover crop within the last 5 years and had an abandoned corn crop which left an unusually high amount of plant residue. Data from the Conv/cc site has not yet been analyzed. No-till/cc treatments had the greatest POM carbon (kg/ha) and more root biomass than the Conv/no-cc system suggesting that No-till/cc treatments resulted in more intermediate pool carbon then conventional systems with no cover crops. Results of the alfalfa-hay systems were less conclusive as the conventional treatment had greater amounts of percent POM but less percent C in the POM then the no-till treatment. Slow pool C as measured by the amount of C-Min carbon in kg/ha was overall greater for the No-till/cc treatments than for the Conv/no-cc treatment, and greater for the no-till alfalfa-hay system then for the conventional alfalfa-hay system. No-till/cc treatments had the greatest amount of microbial biomass (kg/ha), nitrogen (kg/Ha) and carbon (kg/Ha) in both the POM and C-Min fractions. This suggests there is an increase in the size of both the fast and intermediate organic matter pools.