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All publications of “Fernando José Freire”

7 results

Nitrate Reductase Activity and Nitrogen and Biomass Accumulation in Sugarcane under Molybdenum and Nitrogen Fertilization

Renato Lemos dos Santos, Fernando José Freire, Emídio Cantídio Almeida de Oliveira, Maria Betânia Galvão dos Santos Freire ORCID logo , Jason Brossard West, José de Arruda Barbosa, [...]


ABSTRACT Prior research on sugarcane showed increment of productivity following molybdenum (Mo) fertilization and some indication of the potential role either on nitrate reductase activity (NRA). However, this increment can depend on sugarcane variety and nitrogen (N) fertilization. This study aimed to evaluate the effect of Mo fertilization on Mo uptake, on NRA, nitrate (NO3–-N), and ammonium (NH4+-N) contents in leaves and roots of sugarcane, and the accumulation of N and biomass across two sugarcane varieties (RB 867515 and RB […]

Visual Abstract

Isolation and identification of endophytic and epiphiytic bacteria in sugarcane in areas with and without termiticide

Michelangelo de Oliveira Silva, Fernando José Freire, Mario Andrade Lira Junior, Júlia Kuklinsky-Sobral, Diogo Paes da Costa, Luana Lira-Cadete


The exploration and knowledge of bacteria-plant interaction mechanisms may be used for a more sustainable production of several crops, e.g., of sugarcane. The objective of this paper was to isolate bacteria associated with sugarcane with the ability to fix nitrogen and solubilize inorganic phosphate in areas with and without the application of termiticide. Endophytic bacteria were isolated from leaves and roots and from the rhizoplane, four months after planting of three commercial sugarcane varieties (RB 92579, RB 867515 and RB […]

Nutrient uptake and use efficiency of elephant grass in the presence of crude gypsum

Renato Lemos dos Santos, Vinícius Mendes de Azevedo, Fernando José Freire, Alexandre Tavares da Rocha, José Alves Tavares, Maria Betânia Galvão dos Santos Freire


The cultivation of Elephant or Napier grass (Pennisetum purpureum) in the gypsum- producing region of Araripe, in the west of the state of Pernambuco in northeastern Brazil, may be viable as alternative energy, especially when the soil fertility is improved. The objective of this study was to evaluate the effect of crude gypsum on the nutritional status, mineral composition, biomass production, and nutrient uptake efficiency of elephant grass varieties in Araripe, Pernambuco. For this purpose, three elephant grass varieties: Cameroon, […]

Inorganic phosphorus fractions and their relationship with soil phosphorus extracted chemically and by maize plants

Reginaldo Fidelis de Souza Júnior, Fábio Henrique Tavares de Oliveira, Hemmannuella Costa Santos, Fernando José Freire, Jandeilson Alves de Arruda


The fractionation of inorganic phosphorus (Pi) is important to evaluate in which forms phosphorus is sorbed to soil, because the efficiency of an extractant of available P in soils depends on its capacity to extract each fraction of soil Pi. This study evaluated the contents of Pi fractions in representative soils of the State of Paraiba and their relationship with the chemical and physical characteristics of these soils, as well as the correlation between the Pi fractions and P extracted […]

Nutrient extraction and export by fully irrigated sugarcane varieties

Emídio Cantídio Almeida de Oliveira, Fernando José Freire, Ruthanna Isabelle de Oliveira, Maria Betânia Galvão dos Santos Freire, Djalma Euzébio Simões Neto, Silas Alves Monteiro da Silva


A review of technology research supporting the Brazilian sugaralcohol sector shows that only sporadic studies with irrigated sugarcane have been developed to investigate nutritional requirements. In this context, the objective of this study was to quantify the capacity of extraction and export of N, P, K, Ca, and Mg as well as the nutritional requirement for the production of one ton of stalk per hectare (TCH) in the plant cane cycle of 11 sugarcane varieties (SP79-1011, RB813804, RB863129, RB872552, RB943365, […]

Soil chemical properties under different uses in an irrigated area in the semi arid region of Pernambuco, Brazil

Rossini Mattos Corrêa, Maria Betânia Galvão dos Santos Freire, Rinaldo Luiz Caraciolo Ferreira, Fernando José Freire, Luiz Guilherme Medeiros Pessoa, Marcelo Alves Miranda, [...]


Soils developed at semi-arid climate can present salt accumulation, which compromise the agricultural use, being increased by inadequate irrigation management. Based on the use, the degradation of these soils can occur at higher or smaller intensity. This study aimed to evaluate the effect of soil uses based on physical and chemical properties of an irrigated area in the semi-arid region of northeastern Brazil. The soil uses were annual crops (C), fruticulture (F), pasture (P), discarded lands (D), or native vegetation […]

Chemical and physical fractions of soil organic carbon in a forest soil currently under different uses

Arlete Côrtes Barreto, Maria Betania Galvão dos Santos Freire, Paulo Gabriel Soledade Nacif, Quintino Reis Araújo, Fernando José Freire, Euzelina dos Santos Borges Inácio


Organic matter may be considered an important soil quality indicator, as it is related with many soil chemical, physical, and biological characteristics. The study of total organic carbon (TOC) of the soil and its fractions is important. This study was conducted in a micro basin, with the purpose of: analyzing characteristics and quantify the stocks of total organic carbon (TOC) and its fractions as evidence of soil quality after different forms of use: (1) Atlantic Forest, (2) Cocoa (Theobroma cacao), […]