Soil Components


Book Description

Organic substances returned to the soil by plants, animals and microorganisms go through biochemical cycles and subcycles that provide essential media for the growth of plants in the soil. These cycles involve numerous, complicated and interdependent chemical reactions. Many books have been written to describe the genesis, the nature and the reactions of soil organic matter and have contributed much to organizing parts of the knowledge about soil organic matter. Each book is an important contribution but none has duplicated any of the others to any great extent; each has developed essential bu.







Soil Structure/Soil Biota Interrelationships


Book Description

Some pioneers in soil research such as Müller and Kubiëna were as much biologists as they were soil scientists and the legendary biologist Charles Darwin was foresighted in recognizing the earthworms as instrumental in reworking the soil, thereby forming what he called "vegetable mould". Still, soil science has largely been the realm of physicists and chemists over the past decades. Whatever the reason, this picture is rapidly changing. Until recently, research on the transport and transformation of elements in soil was often concerned with either soil biota/plant relationships or with soil structure/plant relationships, if the biota were considered at all, but very few studies explicitly took the interrelationships between soil structure and soil biota into account. The conference on Soil Structure/Soil Biota Interrelationships, held at Wageningen, The Netherlands, 24-28 November 1991, was meant to bridge that gap, focussing on methods of research, organized in three levels: features, processes and effects. The proceedings of the conference are testimony of the need to intertwine the biological, morphological, physical and chemical disciplines in soil research to understand better and forecast soil properties and processes as related to land use for agricultural and other purposes.This book should be of particular interest to soil scientists and ecologists who feel the need for a cross-disciplinary approach in soils research. It should also be a rich source of teaching material for courses in soil science and soil ecology at graduate level and above, with ample reference to studies on land use as related to agriculture and the environment.




Biological Processes and Soil Fertility


Book Description

The success of shifting cultivation systems developed by subsistence farmers testifies to the resilience of the "natural" soil-plant ecosystems to recover from the offtake of nutrients in crops and loss of soil struc ture. By contrast, the development of intensive cropping systems requires large inputs especially of nitrogen, together with phosphorus, sulphur and other essential elements in order to maintain the nutrient levels needed for abundant crop yields. As Dr. Cooke ably pointed out in his introductory lecture, the dis coveries and experiments of the 19th century encouraged farmers in temperate zones to rely greatly on chemical fertilizers supplements. However, the work of Charles Da{win on soil mixing by earthworms and the discovery by Hellriegel and Wilfarth in 1886 that the nodules on legume roots contain colonies of symbiotic bacteria able to "capture" atmospheric nitrogen molecules to the benefit of the host plant heralded a growing realization of the importance of soil biota in fertility studies. Biological fixation of nitrogen has been the theme of many meetings and publi~ations hitherto but at this Conference, convened on the delightful campus of Reading University, attention was mainly focussed on other biological processes in soil fertility. These Proceedings record the dominant themes and include six keynote addresses delivered at plenary sessions and seven introductory lectures to paper reading sessions by invited individuals plus 22 of the proferred papers, in six sections as tabled in the contents list.




Geology of the Country Around Aberdeen


Book Description

A detailed account of the geology shown on the complementary 1: 50 000 (or earlier 1: 63 360) geological map(s)







Soil Survey of Great Britain


Book Description




Groundwater in the Celtic Regions


Book Description