Data/hora: 29/06/2024 08:13:12

Biblioteca(s): | Epagri-Sede.
Data corrente: | 09/09/2021
Data da última atualização: | 09/09/2021
Autoria: | GUIMARAES, G. G. F.; RIBEIRO, C.
Título: | CONTROLLED RELEASE TECHNOLOGY, AGRICULTURAL.
Ano de publicação: | 2021
Fonte/Imprenta: | In: LEY, C. Kirk-Othmer Encyclopedia of Chemical Technology. Hoboken, Nova Jersey, EUA: Wiley & Sons, 2021. p. 1-17
Idioma: | Inglês

Conteúdo:

The agricultural sector is continually seeking new technologies to increase the
efficiency of inputs and minimize possible environmental impacts. These players 
have been proposing to utilize controlled release technologies to optimize the
delivery of nutrients to plants or chemicals to control weeds, pests, and diseases,
for example, herbicides, insecticides, and fungicides targets (1). Despite being a
technology also used in other agrichemicals, this article emphasizes the slow and
controlled release of fertilizers (CRFs), given the higher demand and importance
for crop production. Compared to conventional fertilizers, the main advantage is
the reduction installments of fertilizers, which reflects in labor, energy, and time
savings. Moreover, CRFs reduce the phytotoxicity by the rapid release of nutrients, 
which leads to high ionic concentrations in soil and nutrient loss (eg, through
ammonia volatilization and nitrate leaching) (2,3). There are controlled-release products for different nutrients, but to the best
of our knowledge, there is a particular concern in nitrogen management due to
its high demand. Compared to all other nutrients, the vast majority of available 
products and ongoing developments deal with nitrogen utilization. The world
production of stabilized, slow, or controlled release of nitrogen fertilizers in 2014
was approximately 11.6 million tons, with projections indicating a future global
market growth of 7.5 million tons (4). Asia figures as the biggest producer and 
consumer, with emphasis on China, which uses 2.8 million tons of nitrogen CRFs. Of
this total, 36% are stabilized fertilizers, 26% are sulfur-coated granules, 24% are
urea formaldehyde (UF), and 14% are polymer-coated fertilizers (4). The Indian
market consumes approximately 6.3 million tons of CRFs. Of this total, the stabilized
 fertilizer most used by Indian agriculture is urea coated or treated with
neem oil, whose utilization is encouraged by the Indian government (4). This oil
is extracted from the tree (Azadirachta indica) and acts as an inhibitor of nitrification 
and urease activity (5). The consumption of enhanced efficiency fertilizers in North America and
Latin America are 1.2 and 1.0 million tons, respectively. Despite similar consumption,
in North America, there is a predominance of controlled-release fertilizers, and in Latin America of stabilized fertilizers (4). Europe, on the other
hand, has lower CRFs production and consumption, with values close to 140 000
tons. In general, the worldwide consumption of stabilized nitrogen fertilizers,
slow or controlled release in 2014, was over 12 million tons. Projections indicate
that the global market possibly grows by 7.5 million tons in the upcoming
years. Conventionally, all fertilizers that have undergone some modification to
increase their agronomic efficiency, economic or environmental benefits, are
named ?Enhanced-Efficiency Fertilizers? (6). Nitrogen fertilizers of increased
efficiency are grouped into three categories, according to the technologies used
to increase efficiency: slow, controlled release, and stabilized fertilizers (5). The
Association of American Plant Food Control Officials (AAPFCO) defines slow and
controlled-release fertilizer as ?a fertilizer containing a plant nutrient in a form which delays its availability for
plant uptake and use after application, or which extends its availability to the plant
significantly longer than a reference ?rapidly available nutrient fertilizer? such as
ammonium nitrate or urea, ammonium phosphate, or potassium chloride. Such
delay of initial availability or extended time of continued availability may occur by a
variety of mechanisms. These include controlled water solubility of the material by
semi-permeable coatings, occlusion, protein materials, or other chemical forms, by slow
hydrolysis of water-soluble low molecular weight compounds, or by other unknown
means? (5).

Palavras-Chave: | Fertilizer; Nutrients.
Categoria do assunto: | F Plantas e Produtos de Origem Vegetal
URL: | http://intranetdoc.epagri.sc.gov.br/producao_tecnico_cientifica/DOC_49820.pdf
Registro original: | Epagri-Sede (Epagri-Sede)
Exemplares: | Epagri-Sede - (106139-1) - UPC - PL - DD -  -  -  - DIS