Recovery and reactions of amprolium from poultry manure added to soil

Amprolium, a coccidiostat added to poultry feed, occurs in excreta at concentrations of 204 μ g^?1 and investigations were made of the effect of this quantity of amprolium on the biochemistry of soil to which manure had been applied.Greenhouse experiments showed that 0.8 μg g^?1 amprolium was found in soil pots 80 days after treatment with manure at the equivalent of 56.1 t ha^?1 and was detectable 20 days following treatment at the equivalent of 11.2 t ha^?1.Laboratory experiments indicated that amprolium was differentially adsorbed to two complexing media, soil and manure. Since amprolium was a constituent of treated manure, it was expected that the amprolium manure-soil system would offer various sites for adsorption of amprolium. Mixing amprolium with soil and with soil plus untreated manure yielded approximately the same effect on amprolium adsorption based on recoveries in water solution, and as methanol extractable. However, total recovery of amprolium from treated manure added to soil was only a fraction of the above, indicating the high complexing capacity of the manure.No effect on soil respiration was observed by either pure amprolium or amprolium as a constituent of treated manure. The higher rate of manure application caused greater respiration due to the presence of more readily oxidizable organic matter, but the respiration pattern attributed to the manure component was not unlike the respiration pattern of the Guelph loam soil.     

Carl Ortwin sauer on destructive exploitation

A persistent theme in the work of Carl O. Sauer (1889–1975) is destructive exploitation, the process of economic devastation and its aftermath associated with occidental commercial culture. Coloured by anthropological premise, his conception entailed economic process as cause, e.g. monoculture, and environmental pathology as consequence, e.g. soil wastage. Man is both selective appraiser and selective modifier of his habitat, and many of his surface changes are irreversible. Primitive economies are part of the general symbiosis and infrequently destroy things that are useful to them. Man's terrible destructiveness is an attribute of profit economies, colonial and contemporary. Among other losses, the record of impoverishment includes devastation of native peoples and cultures, extermination of biotic species and varieties, and soil erosion. Sauer infused record of deformation with moral critique. He inveighed against ways that are improvident and called for an ethic and aesthetic under which man may attain wise stewardship of the earth.     

The utilisation of poison hoppers designed for grey squirrel (Sciurus carolinensis Gmelin) control

The grey squirrel is recognised as a pest species of economic importance but the justification of the view appears to be founded on local areas of severe damage. Despite evidence that damage may not be alleviated by squirrel population destruction, Warfarin poisoning was introduced as an alternative to trapping.The utilisation by wildlife of a poison hopper designed for grey squirrel control was investigated by automatic photography. Results confirmed that a number of species may feed from the grain presented via the hopper. However, the majority of the bait was removed during the hours of darkness when grey squirrels were not active. It is a conservative estimate that between 55 and 65% of the grain entered the environment via animals other than squirrels.In addition, the removalof bait by night visitors resulted in the accumulation of large quantities of bait at and around the entrance to the hopper tunnel. This increased accessibility to the potentially poisoned bait by animals other than squirrels.Until such time as evidence is produced to show these results as exceptional, it can only be concluded that fears expressed over the lack of specificity of this method of control are justified.     

Management of the Northern Chesapeake Bay American shad fishery

The Shad fisheries of the Chesapeake Bay in Maryland have been declining since an 1897 peak of 7860 × 10³kg. No periods of stability have been recorded. Data are presented to trace the decline not only as a function of specific areas within the Northern Chesapeake Bay but also in terms of environmental problems and recruitment overfishing.The problem is related to improving the commercial fishing yield. An estimation of a maximum effort of 200,000 man-hours is suggested if a stable yield is to be approached. Methods for obtaining this goal include alternating of closed fishing areas, adoption of rest days, enforcement of fisheries regulations and reduction of the number of metres of gill net used per fisherman.     

Experiments to determine the fate of dead birds at sea

This paper describes three experiments aimed at determining the proportion of dead birds at sea which come ashore and are found by members of the public, and discusses the results in relation to wind velocities. From 11% to 58% of the ringed (Larus spp.) corpses thrown into the Irish Sea between Liverpool and the Isle of Man on three occassions in 1973 and early 1974 were recovered. There were large differences between experiments in the timing of the recoveries, although half usually occurred within 11–14 days of dropping. The resultant wind velocities during the time the first bodies recovered from each experiment were at sea were calculated. Comparison of the observed and expected tracks of these bodies confirmed that the wind was the main factor influencing the direction of drift. Gull corpses drifted at a minimum of 2·55±0·93% of the wind speed, although there was much variation and some travelled at over 4% windspeed. With a few exceptions, the observed distribution of recoveries could be broadley predicted by wind vector analysis. The amount of onshore wind when the bodies had reached coastal waters was not related to the subsequent recovery rates. Further experiments are necessary if some of our findings are to be explained and examination of the effect of tidal cycles on the beaching of corpses would also be of value.     

Hyphal density as a measure of suppression of Gaeumannomyces graminis var. tritici on wheat roots

Runner hyphae of Gaeumannomyces graminis (Sacc.) Arx & Olivier var. tritici Walker on seminal roots of wheat seedlings were photographed and their length measured. As well, their length was estimated using the line-intercept method. The correlation of 0.904 between measured and estimated lengths of hyphae was highly significant. This line intercept method was used to estimate the density (length/unit area) of hyphae on roots of plants growing in the presence and absence of a soil suppressive to G. graminis var. tritici. Estimations were made eight times during 28 days growth at 15°C. In fumigated soil (non-suppressive) inoculated with 0.1% ground oat grain infested with G. graminis var. tritici, the density of hyphae on roots started to increase at five days compared with 15 days when soil there was a 10.8% cover of the root surface after 15 days when the hyphae had reached maximum density. Suppression to G. graminis var. tritici is normally detected by a difference in disease rating of roots at 28 days but this study has shown that suppression can be demonstrated by the difference in the density of hyphae if roots are examined between seven and 19 days.     

A device to study metabolic gases in the rice rhizosphere

A simple apparatus was developed to study metabolic gases in the rice rhizosphere. With this device, a positive rhizosphere effect of rice was demonstrated on three soil microbial activities: N₂ fixation, CH₄ formation and denitrification.     

Acetylene inhibition of nitrous oxide reduction and measurement of denitrification and nitrogen fixation in soil

Reduction of N₂O in moist soil was inhibited completely by 10^?2 atm C₂H₂ and partially by 10^?5 atm C₂H₂. The effect of C₂H₄ was 10⁴ times less than that of C₂H₂. Denitrification of NO^?₃ occurred in anaerobically or aerobically incubated waterlogged soil and in anaerobic but not in aerobic moist soil. In the absence of C₂H₂ there was transient accumulation of N₂O. In the presence of C₂H₂ there was stoichiometric conversion of NO^?₃ to N₂O. Some kinetics of the reduction of N₂O and of NO^?₃ to N₂O are presented. Denitrification of 1 μg added NO^?₃-N.g^? could be measured within 1 h. Stoichiometries of production of N₂O from NO^?₂ and NO^?₃, respectively, and production of CO₂ attributable to denitrification were consistent with reported energy yields. Reduction of C₂H₂ to C₂H₄ occurred immediately following complete denitrification of added NO^?₃. The incubation of soil in the presence and in the absence of C₂H₂ thus permits assay of both denitrification and N₂ fixation and provides information on the mole fraction of N₂O in the products of denitrification.     

The United States energy dilemma: How can we solve it?

Water, Air, & Soil Pollution - The basis for the present energy dilemma is described. The current solution to the inadequate petroleum and natural gas supplies and possible long-term solutions...     

Patterns of energy use and the critical choices ahead

Patterns of energy use in the U.S. by industry, commerce, residential and agriculture with comparisons of Northern and Central California energy use in the same sectors are presented. End-use applications are also covered.