The mechanisms by which potentially soluble inorganic nutrients are retained and eventually recycled within ecosystems have been characterized by many studies. Substantial amounts of potentially soluble organic nutrients are also released as plants grow, die, and decompose. In this study, a conceptual model was developed which shows the pools and signi®cant processes generating and consuming di...

Nitrogen availability is a major factor determining plant growth and productivity. Plants acquire nitrogen nutrients from the soil through their roots mostly in the form of ammonium and nitrate. Since these nutrients are scarce in natural soils, plants have evolved adaptive responses to cope with the environment. One of the most important responses is the regulation of nitrogen acquisition effi...

some contaminants associate with soil particles and, thus, their transport and fate in the environment is determined by the soil erosion processes. eutrophication, low oxygen levels and high nutrient (nitrogen and phosphorus) concentrations in reservoirs, canals and other water courses, is a common water pollution feature. phosphorus (p) is one of the major plant nutrients and also the major nu...

The gastrointestinal tract (GIT) is essentially a long tube extending from the mouth to the anus with a number of specialized regions. Most of the nutrients (Chapter 10) in food have to be digested before they can be assimilated. Digestion involves the hydrolysis of polysaccharides, oligosaccharides, proteins and lipids in enzyme-catalyzed reactions. The products of hydrolysis, such as monosacc...

The weaning transition is characterised by morphological, histological and microbial changes, often leading to weaning-associated disorders. These intestinal changes can partly be ascribed to the lack of luminal nutrition arising from the reduced feed intake common in pigs after weaning. It is increasingly becoming clear that changes in the supply with enteral nutrients may have major impacts o...