Autor(es):
Cordovil, C.
; Teixeira, T.
Data: 2010
Identificador Persistente: http://hdl.handle.net/10400.5/2634
Origem: Repositório da UTL
Assunto(s): organic residues; nitrogen mineralization; degraded soils
Descrição
RAMIRAN International Conference Nitrogen (N) is the nutrient most likely to be limiting for plant and animal production. Also, increasing world
population, is giving rise to the need for more food production, in quantity and quality enough to supply man’s
needs. It is therefore necessary to supply more and more nutrients to the soil in order to achieve the production
levels required to reduce world hunger. Intensive and somewhat indiscriminate use of commercial fertilizers is not
environmentally sustainable, and excessive application of N, as mineral fertilizers, may lead to many environmental
problems such as nitrate pollution of water resources, amongst others.
Simultaneously, intensification of agriculture, as well as the development of industry, has been leading to
the increasing production of organic residues such as manure, municipal solid waste, crop and forest waste, food
industry waste, among others (Sims, 1995). Their application to agricultural land is a good solution for recycling,
can increase soil organic matter content, and to provide plant nutrients such as N, as a good alternative to
commercial fertilizers (Cordovil, 2004).
The application of organic residues to agricultural soils as a source of N needs a better understanding of
the processes involving the mineralization of organic N compounds. A good prediction of the amounts of N
mineralized from the residues is an interesting issue, and also a valuable tool for the sustainable and rational use of
these sources of nutrients for plant growth, while reducing the environmental impact. More than 90% of the N in
soils is in organic forms. Available N is considered to be a fraction of easily mineralizable organic N that can be
estimated based on the mineral N released during incubation of soil at an appropriate temperature. However,
incubation procedures are time consuming, and several chemical methods have been developed as substitutes for
incubations by several authors. Thus, the development of a rapid, accurate and cost-effective method for the
prediction of N supply both from soil organic matter and the application of organic waste materials is of great interest