The goals of the BIOAg compost program are to:

1. Compost Research and Extension for Biologically Intensive and Organic AgricultureLynne Carpenter-Boggs, WSU CSANR BIOAg Batch 1 Batch 2 Batch 3 9 5 8 4 7 6 Log 10 Protozoans 3 Log 10 Bacteria 5 4 2 3 2 1 1 0 0 Protozoan Diverse Fungal Bacterial Protozoan Diverse Fungal Bacterial 2 10 8 1.5 6 Salt content 1 pH 4 0.5 2 0 0 Protozoan Diverse Fungal Bacterial Protozoan Diverse Fungal Bacterial Tea Recipe Tea Recipe The goals of the BIOAg compost program are to: • Expand the use of composting for safe, sustainable waste management. • Increase the use and effectiveness of compost as an agricultural soil amendment and nutrient source. • Improve our understanding of composts and extracts as a resource for plant disease management. On-Farm Livestock Mortality Composting Compost Tea Stability and Use Even under the best management, livestock die on the farm. Given the costs and challenges associated with traditional disposal options such as rendering, on-farm burial, and natural decomposition on range land, many producers are seeking alternatives. The M.S. thesis work of Catilin Price showed that with proper management and materials, on-farm composting is an economical and environmentally sound method of mortality disposal. Compost teas, an aerated mixture of compost, water and nutrient additives, produce a complicated array of microorganisms. While compost extracts have long been used as a source of plant nutrients and beneficial microorganisms, recently producers and the scientific community have looked to harness compost teas for biological control of plant pathogens. Studies on compost tea for plant disease control have shown mixed results, even within the same field-crop-pathogen system. Variability of compost feedstock, additives and brewing conditions can cause variations in the microbial communities of teas. Four tea recipes were brewed three times and tested for chemical and microbial properties. Teas were also mixed with a normal strain of Xcc, and plated next to a strain deficient in a pheromone that controls pigment production. The deficient strain acted as an indicator of Xcc growth, responding to pheromone production from the normal strain. Xcc mixed with the compost tea produced no pheromone. However, when the teas were filter sterilized, the Xcc was able to produce pheromone. This shows that the compost tea microbial community can inhibit Xcc in vitro. Chemical and Biological Stability of Compost Teas The WSU On-Farm Mortality Composting Project was a collaborative effort between the WSU Biologically Intensive and Organic Agriculture (BIOAg) Program, WDOE, and WSDA. Phase I – Collaborate with producers and state agencies to establish mortality compost trial sites across Washington. Phase II - Develop educational resources, including an informational website and a WSU Extension bulletin. Phase III – Survey dairy farmers in Washington currently composting mortalities to determine preferred information sources, compost methods, challenges and impacts. The MS research of Noah Bonds determined the fertilizer value of compost made from mint “slugs”. Example of a mortality composting windrow. Each flag signifies a separate bovine carcass. The MS thesis research of Catherine Crosby determined the stability of compost tea microbial communities between batches of the same recipe, and tested the ability of compost teas to inhibit Xanthomonas campestris (Xcc), the causal agent of black rot. Composting windrows of mint “slugs” Dumping of mint “slugs” Xcc Pheromone Response to Compost Tea or Sterilized Compost Tea At field days, attendees were always surprised at how LITTLE odor came from this process. Growing Sweet Corn in Pullman, WA Setting up field plots Plant byproducts from mint distillation produce as much as 50,000 yd3 of material each year in Royal City, WA. The distillery waste is temporarily stored in large roadside piles , which often begin to smolder from the heat of natural decomposition. The resulting smoke presents a particularly dangerous hazard to automobiles on adjacent roadways. Mint growers working with university researchers found windrow composting to be a solution to the smoldering mint piles. Once composted, the material has great potential as a fertilizer. Performance of the compost was evaluated both in the field and greenhouse. Diverse Tea : Xcc * Only normal strain induces yellowing in test strain. Filter-Sterilized Diverse Tea : Xcc * Both sides of indicator strain show yellowing.