B.S., 1973, University of Wisconsin‑Madison, Soil Science; M.S., 1975, Michigan State University, Soil Science; Ph.D., 1978, Kansas State University, Agronomy. Author or co-author for 230 refereed journal publications and 154 peer-reviewed book chapter or proceedings papers. Co-editor for “Sustainable Agriculture Systems,” “Agricultural Utilization of Urban and Industrial By-Products,” “Sustainable Alternative Fuel Feedstock Opportunities, Challenges and Roadmaps for Six U.S. Regions” and editor for “Cellulosic Cropping Systems.” His currently researches are focused in using soil quality/health assessment to quantify physical, chemical, and biological effects of various soil and crop management practices including sustainable tillage, crop rotation, nutrient management, manure management and cellulosic feedstock harvest for second-generation bioenergy and bio-products.
Managing Crop Residues for Productivity, Ecosystem Services, and the Bioeconomy
Balancing soil carbon (C) is essential for sustainable production of cellulosic, second-generation bioenergy and bio-product feedstock supplies that can be derived from a variety of plant materials including crop residues, perennial forages, dedicated energy crops, woody species, urban lawn and garden waste, unused construction materials, or co-products such as sugarcane (Saccharum sp.) bagasse. During the past two decades, substantial progress has been made globally to identify, collect, store, transport, and develop optimum uses for these materials. This has required close collaboration among chemical, agricultural, and biosystems engineers, as well as agronomists, geneticists, animal nutrition specialists, and soil scientists. Knowledge, skill and abilities from each discipline is essential because C, captured through photosynthesis, not only provides the energy associated with biofuels, but also nutrition for animals, food for soil microorganisms, binding materials for enhanced soil structure, and surface protection against wind and water erosion. Key advances by public and private sector groups have and continue to be made regarding the science and technology needed to efficiently capture and utilize the solar energy to meet ever-increasing food, feed, fiber, and food requirements of an expanding population.
This presentation will focus on the soil C balance, because it provides the connecting link among the multitude of ecosystem services associated with production, collection, storage, and transport of cellulosic feedstocks. Challenges such as how to: (1) manage variable land areas, (2) balance crop residue management to sustain soil resources without creating emergence, stand establishment, growth or yield reductions in subsequent crops, (3) determine the amount of crop residue or plant material that can be sustainably harvested, (4) adjust for additional nutrient removal, (5) harvest without degrading soil physical quality (i.e., compaction, destruction of soil aggregates, crusting, or erosion), and (6) address policy questions such as the effects of feedstock harvest on carbon intensity (CI) estimates will be explored using corn (Zea mays L.) and other field research data in conjunction with the concepts of soil quality or health. Economics of these complex cellulosic management practices will be explored using sub-field return on investment (ROI) concepts and calculations.