Corn Development and Production in Function of Sources of Nitrogen Fertilizers and Doses

Abstract

-Nitrogen (N) is one of the nutrients that have the most significant effect on corn grain productivity increase. In order to evaluate the effect of sources of N topdressing and doses in the grown corn culture, in a conventional till system, it was installed an experiment in the city of Urutaí, Goiás, in the 2012/13 crop, in clayey textured Red Latosol. The experimental design was a randomized complete block design with four replications, with the treatments arranged in a factorial 3 x 5, consisting of three sources (coated urea, urea and ammonium sulfate) and five doses (0, 60, 120, 180 and 240 kg ha -1 ) of N, topdressing, applied in the surface and in a single dose, when the corn plants were in V 4 stage. The hybrid used was the P3646H. We evaluated the following characters: stem diameter, plant height, height of ear insertion, leaf N, number of ears per plant, ear length, number of rows per ear, number of grains per row, 100 grains mass and grain productivity. All characters have a response to nitrogen fertilization and only the height of ear insertion showed no significant difference between sources. The source coated urea showed the best results, indicating that its use may be compensatory, especially in favorable conditions for the NH 3 volatilization, as the application of high doses of N in the surface.

Agronomic performance and severity of common rust in maize under different nitrogen sources

“…Lange et al (2008) state that in no-tillage system the nutrient dynamics as well as their horizontal and vertical variability are different. Oliveira et al (2016) point out that studies with N involve different sowing/cultivation systems, climatic and soil conditions and, therefore, generalizations about N management do not fit well. For the unfolding of sowing/tillage systems within each source of N (TABLE 4), it is observed that the severity of common rust was higher under minimum tillage system, except for treatment without N. Maize remains in the area under minimum tillage and it should not be the cause of the higher severity of rust, since it is a biotrophic fungus, therefore, unaffected by crop residues as a possible source of inoculum.…”

“…Among the factors that contribute to the low average maize yield in Brazil is the incorrect management of fertilizers, especially nitrogen (MEIRA et al, 2009;OLIVEIRA et al, 2016;VARGAS et al, 2015). Nitrogen (N) is a strategic element in maize production and the search for more efficient sources of this nutrient has the potential to strongly impact crop production systems.…”

Yield and chlorophyll index in cabbage in function of enhanced-efficiency nitrogen fertilizers and urea

“…Entre essas, Ratke et al (2011) observaram que a produção de massa fresca de folhas de rúcula foi mais eficiente utilizando ureia revestida com polímeros (Kimcoat N) ou tratada com inibidor de urease (NBPT), em comparação a ureia comum. Resultados similares foram observados por Oliveira et al (2016), na cultura do milho fertilizado com ureia revestida por três polímeros. Pereira et al (2009) avaliaram a utilização ureia comum, tratada com inibidor de urease (NBPT) e recoberta com camadas de polímeros na cultura do milho safrinha.…”

“…Embora a utilização de fertilizantes nitrogenados de eficiência aumentada proporcione redução de perdas de N (Pereira et al, 2009;Abalos et al, 2014;Lemonte et al, 2016;Tao et al, 2018) e aumento na produtividade de culturas como o milho, trigo e arroz (Frazão et al, 2014;Oliveira et al, 2016;Silva et al, 2017;Chu et al, 2018), estudos sobre a eficiência desses fertilizantes na cultura do repolho, ainda são incipientes. Nesse contexto, objetivou-se com esse trabalho avaliar a produtividade e o índice relativo de clorofila (IRC) na cultura do repolho sob aplicação de fertilizantes nitrogenados de eficiência aumentada comparado à ureia.…”

Produtividade De Fava E Milho Em Função Do Sistema De Consórcio Em Regime De Sequeiro Na Região Do Cariri-Ce

“…Observa-se que os maiores resultados de massa da espiga e de produtividade de grãos de milho foram para os tratamentos T3 e T5, justamente os tratamentos com menor população final de milho e apenas uma semente por cova, fato que contribuiu para reduzir a competição por água e proporcionar melhor desenvolvimento das espigas, apesar dos valores observados serem bem inferiores aos obtidos por outros autores (OLIVEIRA et al, 2016;ROVARIS et al, 2017).…”