Search

Nitrogen fixation in various Wisconsin lakes was compared using the C[sub2]H[sub2] reduction technique. Rates of C[sub2]H[sub2] reduction were unaffected by N[sub2] when sufficient C[sub2]H[sub2] was added to the gas phase. Thus in field studies the natural gas phase need not be removed before the addition of C[sub2]H[sub2]. C[sub2]H[sub2] was reduced rapidly in eutrophic waters (Little Arbor Vitae Lake, Lake Mendota and southern Green Bay) but more slowly in oligotrophic waters (Crystal Lake, Trout Lake, Lake Mary and northern Green Bay). C[sub2]H[sub2] reduction was greatest in the surface waters, was largely light-dependent and showed a marked diurnal variation. There was also significant variation with area and with time, and in general acetylene reduction was detected only when heterocystous algae were present. The rate of nitrogen fixation in Lake Mendota, calculated on the basis of weekly measurements taken during most of the ice-free season, was approximately 2.4 kg/ha/year. [ABSTRACT FROM AUTHOR]

The second World War brought unprecedented controls over the American economy. At the same time, and to a considerable extent as an incident to these controls, the economy of the country has been subject to unusually searching observation and measurement. Some of Americans most useful types of information, such as the data provided by the census of manufactures, have not been available. Nevertheless, the files of governmental agencies contain much detailed information on what has been happening during the last few years, and the research arms of these agencies have made many studies of the effects of war on the economy. Although the bulk of this material is not available to the public, a number of valuable and interesting studies have been published, either by the government or by economists who have been working in the government service, and who are therefore familiar with the studies that have been made and with the data that have been collected. What is to be said here is necessarily based on the information that has thus been published.