|Support type:||Scholarships in Brazil - Doctorate|
|Effective date (Start):||March 01, 2011|
|Effective date (End):||January 31, 2013|
|Field of knowledge:||Agronomical Sciences - Agronomy - Soil Science|
|Principal researcher:||Godofredo Cesar Vitti|
|Grantee:||Letícia de Abreu Faria|
|Home Institution:||Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil|
Brazil is a major producer of corn, and although the many benefits related to conservation practices and soil fertility in tropical climate provided by no-tillage system is known that the maintenance of the layer of straw on the soil surface is directly related to the loss of N-NH3 top-dressing, especially when using urea as nitrogen source. Urea is the most widely used nitrogen source, but has serious problems to have high rates of N loss by volatilization. The search for improvement activities and corrective fertilization of corn aims high yields, and economically. The project objective is to assess the agronomic efficiency of urea coated with copper sulphate and boric acid and the use of zeolite, and mixtures of ammonium sulfate and urea coated urea ammonium sulfate compared to traditional sources in the fertilization of corn in coverage under no-tillage system, which will be evaluated in the N losses by volatilization, the influences on soil fertility, the behavior of N (NH4, NO3 and organic N) in soil and the parameters of productivity and crop quality. The project will include three experiments: Experiment 1 - will include implementation of the sources in corn in no-tillage system and the appropriate evaluations in two years experimental Experiment 2 - should be carried out in order to calibrate the assessment methodology loss of N-NH3 and Experiment 3 - that will determine the influence of sources on the behavior of organic N in soil by means of incubation with 15N.