EcoPress

EcoPics #3: Machines replace fire in Brazil

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By Nell Campbell

Brazil is a major sugarcane (genus Saccharum) producer, with plantations supporting processing facilities that make either sugar or ethanol depending on market demands. Historically sugarcane farmers used fire for harvest. They burned off most of the leaves to harvest the standing cane by hand. In recent years the majority of sugarcane producers have shifted towards mechanical harvesting with machines like the one in the picture. The machine chops the cane into sections that drop into a truck headed to the nearest processing facility, while discarding the remaining leaves and other harvest residues onto the ground. This change in harvesting methods means that a large amount of sugarcane harvest residue is deposited on the ground rather than burned and released into the atmosphere. What these changes mean for ecosystem functioning in sugarcane systems is an important current research topic, in order to determine the sustainability and climate impacts of different production practices. For example biomass accumulation and decomposition could increase soil carbon storage or change how greenhouse gases are released from the ecosystem, but the direction and potential size of these changes are not yet known. At Escola Superior de Agricultura “Luiz de Queiroz” (ESALQ, pronounced “ee-SAL-key” by residents), ongoing field research focuses on assessing soil carbon changes and greenhouse gas emissions with burned versus unburned sugarcane harvest. In collaboration with NREL, data from these research sites will be used to evaluate Brazilian sugarcane production as a whole using the DAYCENT ecosystem model. This photo comes from an early August, 2011 harvest on a plantation near Piracaba, Brazil, which sits in the middle of one of the largest sugarcane producing regions in the country.

Bonus fact: Continuing with the emphasis on sugarcane production and use, ESALQ houses a facility to produce cachaça from local sugarcane fields, the key ingredient to Brazil’s national cocktail, the caipirinha.

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Nell Campbell is a PhD student studying the soil impacts of bioenergy production in Dr. Keith Paustian‘s laboratory at NREL. She thinks sugarcane is awesome. She also took all of the pictures in this post.

2 comments

  1. Great post Nell!

    One other thing worth emphasizing is how bad the air pollutant emissions associated with crop waste burning can be for both human and environmental health. Under idealized conditions, the combustion of biomass containing C, H, and N proceeds to CO2, H2O, and N2, respectively. However, an uncontrolled fire in a damp field will result in extremely high rates of intermediates escaping, so-called products of incomplete combustion or PICs. These include CH4, CO, N2O, NOx, and particulate matter, and in many cases these will in turn catalyze ground-level ozone formation. Some of these (CH4, N2O, particulates) are strong climate forcers, while others (CO, NOx, particulates) are very damaging to human cardiopulmonary health even at relatively low concentrations. And ground-level ozone is detrimental to plant growth and can significantly reduce agricultural crop yields. So this change in management can have important co-benefits for human health, agricultural productivity, and climate change, independent of the effects on soil carbon and GHG balance.

    More detail here if you’re interested:
    http://www.nature.com/nclimate/journal/v2/n1/full/nclimate1325.html

  2. Pingback: Sugarcane Burning Alternatives - Maui Bloggers Zone

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