33 research outputs found
Nitrate content and nitrogen loss in drainwater.
On cropped arable land, the nitrate content of drainage water showed a distinct maximum in spring (Mar.-May) and a minimum in autumn (Nov.). On grassland it was more constant during the year, except when N was applied in autumn or winter (liquid manure, f.y.m., liquid ammonia) when the situation was the same as for cropped arable land. An average content of 1-2 mg N/1. was found for grassland, and of 4-10 mg/1. for cropped arable land, depending on the clay content of the soil. From lysi-meter experiments it was found that on cropped arable land (350 mm drainage water per year) and from a soil profile of 100-125 cm with a clay content of 35% or more, little N was lost by leaching. On sandy soils (0-10% clay), however, about 60 kg N/ha could be lost yearly and 20% of the applied fertilizer N was leached out of the profile. On grassland, leaching losses depended on time of application of the N. A better distribution of the applied N during the growing season than on arable land and the high rate of N uptake by the grass greatly reduced the losses of applied N during the period Mar.-June, even on sandy soils. Later on, the losses could rise to a maximum of 40% for N applied in Nov.-A.G.G.H. (Abstract retrieved from CAB Abstracts by CABI’s permission
Size Doesn't Matter: Towards a More Inclusive Philosophy of Biology
notes: As the primary author, O’Malley drafted the paper, and gathered and analysed data (scientific papers and talks). Conceptual analysis was conducted by both authors.publication-status: Publishedtypes: ArticlePhilosophers of biology, along with everyone else, generally perceive life to fall into two broad categories, the microbes and macrobes, and then pay most of their attention to the latter. ‘Macrobe’ is the word we propose for larger life forms, and we use it as part of an argument for microbial equality. We suggest that taking more notice of microbes – the dominant life form on the planet, both now and throughout evolutionary history – will transform some of the philosophy of biology’s standard ideas on ontology, evolution, taxonomy and biodiversity. We set out a number of recent developments in microbiology – including biofilm formation, chemotaxis, quorum sensing and gene transfer – that highlight microbial capacities for cooperation and communication and break down conventional thinking that microbes are solely or primarily single-celled organisms. These insights also bring new perspectives to the levels of selection debate, as well as to discussions of the evolution and nature of multicellularity, and to neo-Darwinian understandings of evolutionary mechanisms. We show how these revisions lead to further complications for microbial classification and the philosophies of systematics and biodiversity. Incorporating microbial insights into the philosophy of biology will challenge many of its assumptions, but also give greater scope and depth to its investigations