Inorganic fertilizers have become the pillars supporting a burgeoning world population. With population doubling during the lifetime of each of us, a tremendous strain has been put on the ability of agriculture to feed mankind. Agriculture has responded magnificently, with yields of most crops more than doubling in the past 15 years. Cereal production mcreased by 150% (Table 1). Unfortunately h...

concentration of carbon dioxide (CO 2 ) by some 30 percent since the industrial revolution, and that rise continues at a rate of approximately 0.4 percent per year. Despite its seemingly minute concentration (only 0.035 percent), CO 2 inhibits the escape of longwave (thermal) radiation emitted by the earth throughout the entire atmosphere, a process known as the “greenhouse effect.” The presenc...

I F we consider that agriculture employed a majority of the population in non-industrial societies and is still man's staple occupation, we must ad-mit that the agriculture of Roman Britain has concerned archaeologists and historians much less than it should, for on its vicissitudes depended to no small degree the well-being and decline of the province. The existence of Roman 'villas' was first...

Book Review/Science in the Media T he place of genetically modified crops in sustainable agriculture has been the subject of heated debate for decades. A new book takes an innovative approach to this debate by presenting the perspectives of an unlikely pair of co-authors [1]. Pam Ronald is a plant molecular biologist, genetic engineer, and supporter of genetically engineering crops for the bene...

ZONE OF TENSION Historically, landscapes graded from urban centers to scattered villages, to a diverse mosaic of farmlands and natural areas (Figure 1). This gradient allowed both a visual and physical transition while maintaining ecologic, economic, and social connections within the larger landscape. Conflicts between urban and rural residents were minimal, in part due to the limited interface...

Iodine (I) is an essential element for efficient dairy cow metabolism. Iodine status is however not well known on farms. The objective was to measure milk and plasma I concentrations in a selected group of commercial dairy herds in central Iranian province of Isfahan. During summer of 1999 and winter of 2000, 11 dairy farms were randomly chosen and a minimum of 10 cows were sampled from each fa...

Background: The programmed cell death 2 (Pdcd2) gene on mouse chromosome 17 was evaluated as a member of a highly conserved synteny, a candidate for an imprinted locus, and a candidate for the Hybrid sterility 1 (Hst1) gene. Results: New mouse transcripts were identified at this locus: an alternative Pdcd2 mRNA skipping the last two coding exons and two classes of antisense RNAs. One class of t...

Current concerns with the sustainability of agroecosystems in different parts of the world have hightened the awareness for careful use of the natural resource base on which agriculture depends. For proper and efficient use of soils and plant/animal genetic material, knowledge of the role of climate is an essential precondition. Several elements of the chapters in Agenda 21, a global plan of ac...

Reported measurements of the dielectric properties or permittivities over broad frequency ranges for some agricultural materials are cited, and graphical data from the cited literature are presented. They include 50-kHz to 12-GHz frequency-domain permittivity data for adult rice weevils and hard red winter wheat, time-domain reflectometry data for the same insects from 30 MHz to 1 GHz, frequenc...