Soil Health continued from page 1 In these experiments industrial fertilizer or animal manure is applied to different cropping sequences ranging from continuous corn to a single year of corn followed by small grains and hay. Mr. Lynn Hoffman, senior research associate, has overseen the experimental plots at Rock Springs for more than 25 years. The trial at Rodale was initiated in the early 1980s.      Beginning in 1996 the researchers also took soil samples several times during the growing season from more than 40 crop fields around the state, including fields on certified organic farms, dairy farms, commercial crop farms, and even farms irrigated with treated municipal wastewater. The soil samples were analyzed for the size of the microbial population and the rate and consequences of its activity. One of the most important discoveries to date with this project is that intense cropping, for example, with continuous corn, does not necessarily lead to poor soil quality. In fact, Lanyon observed the best soil quality in the continuous corn treatment with yearly manure inputs, better than that occurring in chemically fertilized plots or in plots with corn rotated with a legume and small grain crop.      Ana Bucher, a master's degree student in soil science with Dr. Lanyon, measured the activity of various soil enzymes, including phosphatase, sulphatase, and glucosidase, which are important in the synthesis of organic matter or the supply of nutrients to crops. Soil phosphatase levels were consistently lower when industrial fertilizer was used as a nutrient source instead of dairy manure. The manure additions stimulate the activity of soil microbes more than industrial fertilizer does. Phosphatase activity was lower for continuous corn production than for crop sequences that include other crops. However, the differences were less when dairy manure was added on an annual basis to the continuous corn than when industrial fertilizers were used. The influence of soil management on the activities of	sulphatase and glucosidase were similar to phosphatase, but perhaps more sensitive to other crops in the rotations.      Although manure additions seem to stimulate the life of the soil, as seen in the enzymes and the soil microbial biomass carbon, total soil carbon was not a good indicator of the differences in soil management in the small plot experiments.      Tillage practices on the various Pennsylvania farms had less impact on the soil quality indicators studied than did the source of nutrients. The status of soil enzymes for no-till crop fields yielded mixed results; the activities of enzymes from no-till fields were among the highest and the lowest of those studied.       In addition to managing the Farming Systems Trial at Rodale, Drinkwater is interested in the influence of farming systems on global carbon (C) budgets. She's exploring how soil systems can be managed to sequester more C to offset the addition of C into the atmosphere by cars and industrial processes. Drinkwater's research suggests that fields with cover crops retain more C than unplanted fields, so now she's working to figure out why.      The work on soil quality began in 1996 and will continue at least through 1999. Several new questions have been raised by the work: What is the relationship between soil health and crop yield? How much could farmers with a certain existing soil health afford to spend to increase their soil health and still realize a profit on that investment due to increased crop yields? How much treatment is needed to maintain optimal soil health? Additional research will pursue answers to these questions, attempt to develop budgeting methods for soil inputs--such as manure--that promote soil quality, and refine farmer-friendly soil quality tests that can be conducted in the field.      Additional information about soil quality research is available from Lanyon (814) 863-1614 or Drinkwater (610) 683-1437.	Small Grains continued from page 2 over the years, but he does not foresee an endpoint at which further gains would be impossible. He says scientists have long predicted such endpoints, and they have consistently been surpassed. He acknowledges, however, that the easy improvements have been made already, so he predicts increasing use of genetic engineering and molecular techniques in the future.      A new line of research in the breeding program relates to the search for molecular markers closely linked to useful agronomic traits such as disease resistance, maturity, and grain yield. Risius and Dr. David Huff, assistant professor of turfgrass/genetics, are currently searching for a molecular marker associated with the fluorescent seed trait in an oat line. Initial work made Risius and Huff suspect that a molecular marker had been found, but additional genetic research did not support their first conclusion, so they will keep looking. The fluorescent trait is being used as a model for marker-assisted selection of agronomically important traits for crop improvement.      Other Penn Staters involved in the small grain breeding program include Dr. Elwood Hatley, professor of agronomy, who provides management information to growers of small grains; Harold Marshall, retired plant breeder with the Agricultural Research Service, U.S. Department of Agriculture; Mahlon "Buck" Fetzer, agronomy technician; Leslie Cregger, coordinator of farm and greenhouse operations; and Drs. Barbara Christ and Fred Gildow, associate professors of plant pathology.      Risius clearly loves his work. "Plant breeding is a creative science," he says, "you're creating something that's new and better." Pennsylvania grain farmers are lucky to have Risius in the sidelines continually working to improve the profitability and hardiness of small grains. Risius can be reached at (814) 865-1138; e-mail mlr6@psu.edu.