. IntroductionRecently, an increasi

. Introduction
Recently, an increasing concern about the quality of Brazil’s productive agricultural environments (agro ecosystems)
has developed.
In the last few decades, this concern has greatly influenced the adoption of
‘‘conservationist cropping systems’’ that are based on lower soil disturbance and leaving plant residue on the soil surface.
Those ‘‘conservation cropping systems’’ most used by Brazilians growers include no tillage systems that use direct
seeding, sugarcane harvesting with no previous burning (green harvesting), green manure and minimum tillage.
In Sa o Paulo state, the sugarcane cropping system is an example of agricultural system that is changing due to
social pressure. Brazilian government has mandated (Act no. 47,700 of March 1st, 2003, regulates the law 11,241 of
September 19th, 2002) that in flat sugarcane production areas (degree of slope less than 12% — feasible for
mechanical harvest), the use of fire to reduce biomass before harvest must be reduced gradually year after year up
to 2021, when burning sugarcane prior to harvest should be banished completely. Areas that are unfeasible for mechanical
harvest, but cultivated with this crop (degree of slope