A Comparison of Static Pile and Turned Windrow Methods for Poultry Litter Compost Production

Alternate technologies of compost manufactured from poultry litter (manure) were studied as a means of producing a value-added product for the landscape and nursery industry. Static pile and turned windrow technologies were investigated on a commercial scale with the composting of nearly 300 tons of material. The major difference between the technologies is the amount of energy and labor required. Static pile systems require less energy but more time than windrow turned systems. There was no process advantage found for passively aerated static piles over static piles but costs of passive aeration for pipes and labor were higher than for static piles. Machine turned windrows completed active temperature production within 100 days while portions of both the static and passively aerated piles continued to actively compost past 300 days. Process operational costs and compost quality were similar among the compost methods studied. Production operational cost is driven by the cost of compost ingredients and accounted for 60 to 70% of the cost in the pilot study. Ingredients were poultry litter, wood chips and sawdust. Screened compost was produced at an operational cost of $30 while unscreened compost could be produced for $20 per ton of compost. A production scheme where poultry litter is static pile composted on farms for later transport to regional processing centers appears feasible. This two-part composting procedure will eliminate the transport of raw litter and improve poultry biosecurity. Most likely, a private compost business would provide the expertise, on-farm compost procedures and operate the regional facility.     

Selecting for resistance to diseases in early generations

Screening in the seedling and first clonal generations is a potentially cost-effective and efficient way to incorporate resistance to important diseases and reduce large breeding populations to manageable size. In practice, however, early screening is often limited by the need to maintain clean seedstocks of promising clones, unreliability of single-plant evaluations, associations of disease resistance with undesirable horticultural characteristics, or the higher priority placed on traits other than disease resistance. Possible methods to overcome these limitations are discussed. Examples of early generation screening for resistance to several diseases are given.     

Immune response in rams experimentally infected with Brucella ovis

Cellular as well as humoral immune responses were detected in six rams experimentally infected with Brucella ovis. Specific antibodies were detectable by enzyme-linked immunosorbent assay by day 11 after infection in all the rams. The levels of IgM antibodies and total antibodies in the serum rose until 33 and 41 days after infection respectively, then levelled off. Antigen-induced blastogenic responses by lymphocytes developed as early as five days after infection in all rams but had decreased to low levels by day 63 in most. Blastogenesis induced by phytohaemagglutinin and concanavalin A varied among infected rams and did not differ significantly (P greater than 0.05) from control rams. All rams had developed delayed-type skin hypersensitivity by day 63 after infection. One ram which did not become infected as a result of exposure had low levels of B ovis serum antibodies and a detectable antigen-induced lymphocyte blastogenic response before infection, suggesting the involvement of cell-mediated immunity in protection against B ovis.     

Inoculation of young pine seedlings with Peridermium pini from north-east Scotland

Seedlings of Pinus sylvestris, P. nigra ssp. laricio, and P. mugo vars mughus, rostrata and pumilio were inoculated at their cotyledon stage with aeciospores of Peridermium pini from north-east Scotland. Infection was determined by the presence of both mycelia and haustoria in free-hand or paraffin sections. In the second growing season, infected seedlings showed symptoms such as stem-swelling, development of spermogonia and aecia, and death. In a second experiment, young P. sylvestris seedlings from seven seed sources collected in Great Britain were inoculated and the infection were examined after 6 weeks. In the samples of 50 seedlings from each source, 30–70% seedlings were infected.     

Climate Change During the Last Deglaciation in Antarctica

Greenland ice core records provide clear evidence of rapid changes in climate in a variety of climate indicators. In this work, rapid climate change events in the Northern and Southern hemispheres are compared on the basis of an examination of changes in atmospheric circulation developed from two ice cores. High-resolution glaciochemical series, covering the period 10,000 to 16,000 years ago, from a central Greenland ice core and a new site in east Antarctica display similar variability. These findings suggest that rapid climate change events occur more frequently in Antarctica than previously demonstrated.