Agriculture Reference
In-Depth Information
slow release of agrochemicals, the fundamentals of key technologies, and the
current perspectives in the production of new materials, comparing their potential
with conventional materials regularly produced.
11.1
Introduction
Estimates indicate that the world population will reach 9.5 billion by 2050 (Geohive
2012
), and this population growth comes with the need to increase production of
foods. Brazil has promoted a significant increase of national grain production due to
the use of novel technologies in field, which make better use of natural resources,
and this increase in productivity is supplying the growing domestic and worldwide
demands. From 1992 to 2012, the Brazilian grain production increased by 143 %,
while the planted area increased by only 32 %. This increase in the efficiency of
grain production was accompanied by the consumption growth of agrochemicals
such as fertilizers and pesticides. For example, the growth in fertilizer consumption
was 217 % in the same period. Brazil ranks as the fourth largest consumer of
fertilizers in the world, consuming approximately 29.1 million tons in 2013, which
is equivalent to 6 % of worldwide fertilizer consumption. In the same year, the
consumption of nitrogen fertilizers was 3.3 million tons, being only 33 % of this
amount supplied by domestic production (ANDA
2013
).
However, many agrochemicals applied to crops are not fully exploited by the
agricultural production chain. Processes such as leaching or surface runoff, vola-
tilization, immobilization, or even erosion may cause losses of some agrochemicals
(Resende
2002
; Benke et al.
2008
). These losses cause directly and indirectly a
decrease in productivity and quality of crops, in final profits, and also damage the
environment. Agrochemical industries have been working to improve the efficiency
of using inputs, by studying the best possible agronomic practices, from fertiliza-
tion to prevent pest attack in order to benefit farmers, increasing the productivity,
improving quality of food, and preserving the environment (Finck
1992
). Various
application technologies have also been explored to mitigate or even nullify these
effects.
An alternative to enhance the efficiency of agrochemicals is the use of systems
that could present a lower or controlled release of the desired compound. It should
be noted that there is no official distinction between “slow-release system” and
“controlled-release system.” Nevertheless, it is proposed that the term slow release
is associated with the delay of the release mechanism, but not changing the
mechanism itself, while in the case of controlled release, a change on the type of
delivery mechanism would be responsible for delaying the nutrient release (Trenkel
2010
).
The delay of initially available compounds or the extension of their continuous
availability period. can occur by several mechanisms. The main strategy is to coat a
