Compost Science Complete scientific data on compost process control and end product quality

CURRENT RESEARCH PROJECTS

CSU Winter, 2004, Vol. 12, No. 1, p. 4

CROP IMPROVEMENT
Creating Compost To Serve Plant Needs In Potting Soils
Investigator: Mark T.F. Highland, Longwood Graduate Program, University of Delaware, Newark, Delaware
Objectives: To produce compost with specific physical and chemical characteristics for use in potting soils at Longwood Gardens. For compost to become a standard component of potting soil, plant growth

must consistently rival that of plants grown in traditional peat-based potting soil. The research has two parts: Examine the relationship between compost feedstock materials and resultant mature compost characteristics; and Investigate plant growth responses when compost replaces the peat component.

ENVIRONMENTAL IMPACT
Determining Oxygen Consumption, Carbon Dioxide Evolution And Heat Released During Composting
Investigators: D. Notton, G. Hewings, A. Griffiths and K. Williams, Cardiff University, Cardiff, Wales, UK
Objectives: As the composting process becomes more widely recognized to be increasingly important to achieve recycling targets in the UK, researchers focus on analytical approaches to improve the process. The research was done at the Carmarthenshire Environmental Resources composting facility in Nantycaws.

An Agroecological Basis For Conversion Of Conventional Farming Systems To Organic Management
Investigator: Miguel A. Altieri, Department of Agroecology, University of California, Berkeley, California
Objectives: To improve the transition of agricultural systems beyond input substitution through two main strategies: habitat manipulation via vegetational diversification and enhancement of soil biodiversity via organic soil management. At least 30 percent of the 12 million hectares under organic farming in the world are managed as large monocultures using input substitution. These systems suffer many of the deficiencies of conventional agroecosystems which they are supposed to replace as alternative models.

Effects Of Compost On Arsenic Leachability In Soils
Investigators: Aziz Shiralipour, Lena Mia and Rocky Cao, Department of Soil and Water Science, University of Florida, Gainesville, Florida
Objectives: To provide experimental data to evaluate the effect of composted material in preventing or reducing arsenic leaching into groundwater. Special tasks include evaluation of the impact of composted material to screen the most effective compost for reducing arsenic leachability; to examine feasibility of fern biomass reduction via composting to lower disposal cost, and to compare cost with chemical remediation.

MATERIALS AND METHODS
Developing Better Waste Disposal Alternatives At Food Processing Companies
Investigator: Kurt A. Rosentrater, Department of Engineering and Industrial Technology, Northern Illinois University, DeKalb, Illinois
Objectives: To encourage development of systematic approaches for waste disposal alternatives that would increase revenue from sale of by-products and reduce landfill costs for food processing companies. Seven-step approach to more effectively utilize food processing residuals includes identifying, quantifying, characterizing, developing, analyzing, optimizing and modeling the specific waste stream under consideration.

Sequential Batch Anaerobic Composting (Sebac) For Managing Agricultural Wastes
Investigators: Jose R. Sifontes and David P. Chynoweth, Agricultural and Biological Engineering, University of Florida, Gainesville, Florida
Objectives: To demonstrate feasibility of the sebac technology to process horse bedding, also evaluating process performance and quality of by-products. The process uses a combination of solid phase fermentation and leachate recycle to provide a method that inoculates new batches, removes volatile organic acids, and concentrates nutrients. The process has been tested on high solids feedstocks, including woody biomass, organic fraction of MSW, yard trimmings, blends of trimmings and biosolids.

Cocomposting Olive Oil Mill Wastewater Sludge With Tree Cuttings
Investigators: C. Plaza, N. Senesi, G. Brunetti and D. Mondelli; CSIC, Madrid, Spain; Department of Biology, University of Bari, Italy
Objectives: To evaluate the evolution during composting of two different mixtures of an olive mill wastewater sludge with tree cuttings, and of the fractions isolated from these mixtures. Olive oil mill extraction is an important food industry in the Mediterranean countries, which traditionally use a three-phase centrifugation system that generates a solid by-product used for further oil extraction.

Comparative Study Of Turned Windrows And Static Tunnel Composting Systems
Investigators: Ramon Plana and Carlos Perez, Department of Ecology and Animal Biology, University of Vigo, Spain
Objectives: To make a comparative study of the evolution of the composting process in closed static methods (tunnels) and open dynamic methods (turned windrows), and how the different processes affect basic parameters: temperature oxygen levels, moisture, pH, electrical conductivity and organic matter.

Comparing Plant Growth Of Perennials In Seaweed Compost And Biosolids Compost
Investigators: Wagner Vendrame and Kimberly K. Moore, Research and Education Center, University of Florida, Fort Lauderdale, Florida
Objectives: To compare the growth of different perennials such as coreopsis and shooting star in a seaweed and yard trimming compost and a biosolids and yard trimming compost. Although peat and bark remain the most popular types of substrates, more growers are identifying compost as their preferred choice. Perennials were transplanted into containers filled with, by volume, (1) 100 percent compost; (2) 60 percent compost, 25 percent vermiculite, 15 percent perlite; (3) 30 percent compost, 30 percent sphagnum peat, 25 percent vermiculite, 15 percent perlite; (4) 0 percent compost, 60 percent sphagnum peat, 25 percent vermiculite, 15 percent perlite.

Using Compost Tea To More Effectively Manage Sugarcane Trash In Fields Without Burning
Investigators: Steven Hall, David Schellinger and William Carney; Department of Geological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana
Objectives: To explore innovative methods for improving profitability and environmental stewardship by better managing sugarcane trash mat. The study focuses on trash mat management via composting, mechanical grinding and biological methods, specifically improved methods to decompose materials in the field using compost teas as inoculums sprayed on ground and unground trash mat.

Temperature And Moisture Effects On Decomposition Rate Of Paper Fiber And Broiler Litter
Investigators: K. Ekinci, H.M.Keener, F.C. Michel and D.L. Elwell ; Department of Agricultural Machinery, Suleyman Demirel University, Isparta, Turkey; and Department of Food, Agricultural and Biological Engineering, Ohio State University, Wooster, Ohio
Objectives: To develop a procedure to determine the effects of temperature and initial moisture content of compost on the decomposition rate of paper fiber and broiler litter. A laboratory-scale (5x5x2 factorial design) incubator bioreactor system was developed that included ten 2.76 L bioreactors.

Composting Poultry Mortalities On Farms
Investigators: Luisa J. Gonzalez and Mercedes Sanchez, Department of Sciences Agroforestales, University of Valladolid, Palencia, Spain
Objectives: To determine if composting can be effectively used for treatment of dead poultry on an intensive production poultry farm, utilizing waste materials on the farm such as straw and hen manure. Different composting systems were tried such as a closed system with forced aeration, as well as open air and pile methods.

Analyzing Methods For Composting Animal Waste And Straw Mixtures
Investigators: M.J. Curtis, W.A. Kleiner, V.P. Claassen and R.A. Dahlgren; Land, Air and Water Resources, University of California, Davis, California
Objectives: To examine the physical and chemical differences from using the turned windrow, static passively aerated uncovered and static passively aerated covered composting methods. To examine differences between methods, spatial and temporal differences in temperature, moisture content, pH, microbial respiration, carbon content and nitrogen content.

MICROBIAL ECOLOGY
Fungal Antagonist With Plant Growth Promoting Properties
Investigators: C.R. Thornton and A.C. Groenhof, School of Biological and Chemical Sciences, University of Exeter, Eco Diagnostics Ltd., United Kingdom
Objectives: To add value to green waste compost by incorporating a specific fungus into mature composts as an artificial inoculant. Recent studies have isolated a strain of T. hamatum (BAN12/B3) that exhibits strong biocontrol properties and is able to control pre and postemergence damping-off diseases caused by R. solani and P. ultimum in a wide range of plant species. Furthermore, when introduced as an artificial inoculant into peat-based growing media, it stimulates consistent growth promotion in a large number of plants including lettuce, radish, pea and carrot. For example, in lettuce there is a five-fold increase in the production of green matter and root material after two weeks growth in peat moss when compared to controls. Work is currently underway to extend these studies to determine whether the growth promoting effects of BAN12/B3 can be applied to green waste composts that are chemically and biologically more complex than peat-based growing media. By augmenting the growing medium with this fungus, the disease suppressive and growth promoting properties of green waste composts could be enhanced.

Utilizing Wood Chips In Compost To Manage Soil Microbial Communities For Disease Suppression
Investigators: J.A. Entry, C.A. Strausbaugh and R.E. Sojka, USDA Agricultural Research Service, Northwest Irrigation and Soils Research Laboratory; University of Idaho, Kimberly, Idaho
Objectives: To determine in a greenhouse study the efficacy of wood chips to manage soil microbial communities to alter the soil environment to favor indigenous soil microorganisms in vegetable and manure compost and to reduce Verticillium dahliae infection of potato plants. The study was designed to provide evidence that changing the soil environment to favor biological control or indigenous soil microorganisms for control of soil pathogens may give producers an alternative to soil fumigants.

Microbial Recolonization Of Compost To Increase Damping-Off Suppression
Investigators: Steven Scheuerell and Walter Mahaffee, Department of Botany and plant Pathology, Oregon State University; USDA-ARS Horticulture Crops Research Laboratory, Corvallis, Oregon
Objectives: To determine if manipulating compost curing with rapid decreases in compost temperature could create relative microbial voids to help the nursery industry consistently use the compost as a disease suppressive material. A survey of yard trimmings compost from large piles that did not allow for efficient heat removal indicated that immediate use did not always suppress damping-off by Pythium ultimum.