Saturday, August 22, 2009

Front Diagram Of Ship

Equação ambiental

12/8/2009
Por Fábio de Castro, Agência de Atibaia
Fapesp - Reduce as emissões dos gases de efeito estufa (EGE) que causam or aquecimento global and one of the main reasons for the current international effort that aims to replace fossil fuels for clean energy sources like ethanol from sugar cane. But the fertilizers needed for biofuel production may have a role in their own GHG emissions. This paper
fertilizer use in the emissions need to be carefully studied so that you can understand the environmental balance of sugarcane crop, according to Heitor Cantarella, a researcher at the Agronomy Institute (IAC), Campinas (SP) and an expert on fertility soil and fertilizer. Cantarella
participated on Tuesday (11 / 8) of Workshop Biofuel Technologies and its implications in the use of water and land, which is being held in Atibaia (SP) to the 12th of August. The event is sponsored by FAPESP Research Program on Bioenergy (BIOEN) and the National Institute of Science and Technology (INCT) Biotechnology for bioethanol. According
Cantarella, who is one of the coordinators of BIOEN, nitrogen contained in fertilizers used in farming of cane sugar has a significant role in relation to GHG emissions.
"When we use sugar cane for biofuel production need to evaluate the impact of culture on the GHG balance. Nitrogen enters into the equation because it penetrates into the soil through microbiological reactions, it causes the release of small quantities of nitrous oxide, an important greenhouse gas, "said Cantarella Agency FAPESP.
The intensity of the greenhouse effect caused by each molecule of nitrous oxide is almost 300 times greater than that caused by a molecule of carbon dioxide, according to Cantarella. The Intergovernmental Panel on Climate Change (IPCC) suggests that about 1% of nitrogen fertilizer used on crops ends up being sent to the atmosphere as nitrous oxide.
"But it is important to note that the IPCC numbers are general. There are few evaluations on the production of nitrous oxide used for growing sugar cane. It is necessary to measure the conditions of production of sugarcane, which is the real contribution of nitrogen, "he said.
According to him, in the case of cane sugar, the fact that nitrogen be done in relatively dry season theoretically create conditions unfavorable for the production of nitrous oxide in soil. But the lack of studies prevents an accurate assessment. "That number needs to be evaluated in practice," he said. The
continues to expand sugarcane cultivation in São Paulo and this trend will proceed. "Despite the expansion, the environmental point of view the problem of emission of nitrous oxide is not so great. On the other hand, he acquires a crucial importance when we make an environmental review of a culture that has the mitigation of GHG emissions from their goals, "he said.
The use of fertilizers in the cultivation of sugar cane, also according to the Chairman of the Board of Trustees of the Foundation for Support of Agricultural Research, is in general quite efficient. With the same amount of fertilizer applied to other crops, the cane has a much higher production of biomass.
"Still, the growing of sugar cane, for its extension, accounts for a share of 13% to 17% of all fertilizer used in Brazilian agriculture, "he said. New challenges



The main obstacle to the efficiency of fertilization in sugarcane cultivation in the state with regard to recent technological changes. "With increases in the area with mechanized harvesting, we have a lot of straw on the soil surface. This complicates the incorporation of fertilizers, which are often left exposed. And one of the main nitrogen fertilizer used on this crop, urea is subject to large losses by volatilization, "Cantarella said. A
possible solutions to the problem, he said, would use any other source than urea. "But this kind of alternative is more expensive and less abundant," he said. Other
viable solutions would be to incorporate a mechanical device or use of additives to reduce losses. "We are not yet a practical and economic well-established. It is a challenge we have to solve, "he said.
Another issue that needs further study, points out, is the role of certain bacteria associated with sugarcane crop to fix nitrogen from the atmosphere. This alternative of biological nitrogen fixation could reduce the need fertilizer - which would have major environmental and economic impacts.
"But the magnitude of this setting is not well established. The numbers in the literature are quite variable. Our challenge is to establish such a contribution and find out if we can improve it - with the inoculation of microorganisms or by more efficient selection of varieties of cane sugar that respond better to the process, "he said.