Presently, there is a basic lack of information concerning the accumulation of antibacterial agent residues in agricultural soils. In this field study, performed in southern Denmark, we assess the dissipation of chlortetracycline (CTC), and tylosin A (TYL A) as a function of time. Field soils were classified as a sandy loam soil (field A) and a sandy soil (field B) and each field was sampled on six occasions during the 155-d experimental period from May to October 2000 for chemical analysis and counts of colony-forming units (CFU) detecting the level of aerobic bacteria surviving antibiotic exposure. Colony-forming units and TYL A were detected throughout the entire sampling period, with respective starting soil concentrations of 30 and 50 microg kg(-1) soil declining to 1 and 5 microg kg(-1) soil, on day 155. Compound half-lives (95% confidence limits in parentheses) were estimated for both fields and T1/2 for CTC was 25 d (20-34) and 34 d (28-42) in fields A and B, respectively, and T1/2 for TYL A was 67 d (54-86) and 49 d (40-64) in fields A and B, respectively. No significant difference was determined between compound half-lives on the two fields. The level of aerobic antibiotic-resistant bacteria in the soil over time and soil fauna community was assessed in relation to application of manure containing antibacterial agents to the agricultural fields. The level of both CTC- and TYL-resistant bacteria was affected in the soil by amendment of manure, but declined during the study to the same level as observed at the beginning.

Aldicarb was applied to potato plants in two locations in Wisconsin to determine the effects of application procedures and irrigation on degradation and movement of aldicarb residues, plant uptake, insect control and crop yield. Two application procedures (3.36 kg. AI/ha applied in the furrows at planting and 2.24 kg AI/ha applied as a top‐dress application consisting of a surface‐applied band covered with soil at plant emergence) and two irrigation regimens (medium water use based on evapotranspiration and heavy water use based on evapotranspiration plus 60%) were tested. The emergence application was effective in reducing the downward movement of aldicarb residues without significantly affecting performance as measured by insecticidal efficacy, crop residues and yield. Excess irrigation increased downward movement of aldicarb residues in soil, diminished foliar residues and resulted in decreased insect control and crop yield. Differences in soil characteristics, primarily in water‐holding capacity, were important in reducing downward movement of aldicarb in soil.

ABsmAcT-The literature on "dry socket" is reviewed. The diagnosis, incidence and predisposing factors are discussed in relation to its aetiology. Treatment regimes are outlined; in particular, the use of anti-fibrinolytic drugs. (Hcccivetl for publicariorr October, 1977) 'Birn, H.-Kinines and pain in "dry socket". Int. J. Oral Surg. 1 2 , 3442 (Apr.) 1972. 3MacGreior, A. J.-Aetiology of dry sockets: a clinical investigation. Brit. J. Oral Surg., 6:1, 49-58 (July) 1968.

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