Carbon and nitrogen cycling and microbial activity influenced by mineralization of an organic conditioner in the soil (C.O)

• Grant number: 12/22087-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2013
• End date: January 31, 2014
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Elke Jurandy Bran Nogueira Cardoso
• Grantee: Carolina Bernardino de Campos Miranda Caetano
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The humic substances comprise a complex mixture of molecules resulting from digestion and resynthesizing of the organic material without a defined standard chemical formula. They are highly recalcitrant, with the potential to improve the chemical, physical and biological soil attributes. The importance of humic substances to soil fertility and nitrogen cycling comes from the fact that these materials are relatively resistant to the attack by micro-organisms and may represent a form of nutrients not immediately available to plants but of slow-release. An important economic strategy is to synchronize the release of N, through the decomposition of organic matter, with the need for this nutrient by plants. The use of organic substances, such as humic acids, is interesting because of their recalcitrance and therefore greater persistence in the soil, prolonging the effect of nutrient availability and improving physical and chemical characteristics of the soil. The use of organic acids can alter the energy flow and nutrient availability in the soil, which possibly can be measured by microbiological parameters such as microbial biomass and activity in the soil. (AU)