Assessing a sustainable sugar cane production system in Tucumán, Argentina: Part 2: Soil water and thermal regime, stalk population dynamics and sugarcane production Evaluación de un sistema sustentable de producción de ca a de azúcar en Tucumán, R. Argentina: Parte II: Contenido de humedad y temperatura del suelo, dinámica de la población de tallos y producción de ca a de azúcar

The need to implement sustainable and productive systems compatible with populations leads to the elimination of burning as a practice associated with sugarcane harvesting. This work is part of a study where two sugarcane production systems were compared: a) with trash blanket (mulching) and b) without trash blanket (burnt residue). Macroplots were established in a commercial field planted with LCP 85-384, in Albarracín (Cruz Alta, Tucumán, Argentina). A split-plot experimental design with three replicates was used. Each plot consisted of five 30-m furrows. Two crop cycles were considered: 2006/2007 and 2007/2008. From sugar cane harvest onwards, soil water content at 20-cm and 40-cm depth, soil temperature at 15-cm depth, stalk number and basic infiltration rate were periodically determined. Cane yielding (t/ha and t/100-m row) was estimated at harvesting time using stalk number and weight data. There was a higher water content in the treatment under trash blanket management for the 2007/2008 cycle, but no differences were found between treatments in the 2006/2007 cycle. These results depended on rainfall amount and distribution. Soil temperature was higher in the treatment without trash blanket and this situation was registered until canopy closure. Stalk population dynamics showed a higher stalk number during tillering peak in the treatment with trash blanket. At harvesting time this trend was evident, but the difference was significant only in 2007/2008. Sugarcane production per hectare was 12% and 55% higher in the treatment with trash blanket in 2006/2007 and 2007/2008, respectively. La necesidad de implementar sistemas productivos sustentables y amigables con las poblaciones vecinas a los campos conduce a la eliminación de la quema como práctica asociada a la cosecha de la ca a de azúcar. Este trabajo forma parte de un estudio donde se compararon dos sistemas de producción de ca a de azúcar: a) con cobertura de residuos de cosecha ("mulching") y b) sin cobertura de residuos de cosecha (residuo quemado). Se establecieron macroparcelas en un lote comercial implantado con el cultivar LCP 85-384, en Albarracín, Cruz Alta, Tucumán, R. Argentina. El dise o experimental fue de parcelas divididas con tres repeticiones, estando cada parcela formada por cinco surcos de 30 m. Se evaluaron dos ciclos agrícolas: 2006/2007 y 2007/2008. A partir de la cosecha, se determinaron periódicamente la humedad del suelo a 20 cm y 40 cm de profundidad, la temperatura de suelo a 15 cm de profundidad, la infiltración básica y el número de tallos. Al momento de cosecha, se