Traffic control with autopilot as an alternative to decrease soil compaction in sugarcane areas

Control the machinery traffic through autopilot and use the combined spacing of two rows are possible solutions to mitigate soil compaction problems. The objective of this study was to evaluate traffic control using autopilot in order to soften the problem of soil compaction in mechanically-harvested sugarcane areas. The study was conducted in two experimental areas belonging to Usina Santa Fe, in New Europe, São Paulo, Brazil. The design was a randomized block design, with 3 treatments: T1 = sugarcane planted in single spacing and without autopilot (1.50 m); T2 = sugarcane planted in single line spacing and managed on autopilot; T3 = sugarcane planted under combined spacing of two rows (1.50 × 0.90 m) and managed with autopilot, with 4 replications. Was collected samples in the wheel row (WR) and the seedbed (SB), which was located next to the plant row to, in layers from 0.00 to 0.15 and 0.15-0.30 m. It was observed that the seed bed area showed higher porosity in the treatments with autopilot in the second year of evaluation. There were no differences in pore sizes and shapes between the treatments in the two years studied. The large and complex pores were observed to be reduced in the second evaluation year.The authors thank the Foundation for Research Support of the State of São Paulo (FAPESP) for funding the research, through projects linked to the processes 2012 / 21094-0 and 2012 / 144-6

Variabilidade espacial de atributos do solo e produtividade da cultura de cana-de-açúcar em relação a localização topográfica

Soils submitted to the same management system in places with little variation of landscape, manifest differentiated spatial variability of their attributes and crop yield. The aim of this work was to investigate the correlation between spatial variability of the soil attributes and sugarcane yield as a result of soil topography. To achieve this objective, a test area of 42 ha located at the São João Sugar Mill, in Araras, in the State of São Paulo, Brazil, was selected. Sugarcane yield was measured with a yield monitor fitted in a sugarcane harvester and GPS signal. A total of 170 soil samples were taken at regular 50 m grid, at a depth of 0 - 0.2 m. The area under study was divided into two sites based on topography. The following soil attributes were analysed: organic matter (OM) content, exchangeable potassium (K), calcium (Ca) and magnesium (Mg), their base saturation percentage (%BS), cation exchange capacity (CEC), pH, clay, silt, total sand and density. The use of landscape and geostatistics enable defining areas with different spatial variability in soil attributes and crop yield, providing the visualization and definition of homogeneous management zones. The largest spatial variability of soil attributes and sugarcane yield was in the lowest part of the field.Solos submetidos ao mesmo sistema de manejo em locais com pequena variação de relevo manifestam variabilidade espacial diferenciada de atributos do solo e das plantas. Objetivou-se com este trabalho estudar a correlação entre a variabilidade espacial de atributos físicos e químicos do solo com a produtividade da cana-de-açúcar em duas posições do relevo, de acordo com a topografia da área. O estudo foi realizado no município de Araras, SP, em uma área de 42 ha, pertencente à Usina São João. Para o mapeamento da produtividade da cultura da cana-de-açúcar utilizou-se um monitor de produtividade acoplado à colhedora e ao sinal de GPS. Coletaram-se 170 amostras do solo, em uma malha regular de 50 m entre pontos, na profundidade de 0,0 - 0,2 m. O talhão de estudo foi dividido em duas áreas menores, segundo a topografia. Os atributos do solo avaliados foram: teor de matéria orgânica (MO), potássio (K), cálcio (Ca), magnésio (Mg), saturação por bases (V%), capacidade de troca catiônica (CTC), pH, argila, silte, areia total e densidade. O uso do relevo e da geoestatística possibilitou definir áreas com diferentes variabilidades espaciais para atributos do solo e produtividade da cultura de cana-de-açúcar, proporcionando a visualização e definição de zonas homogêneas de manejo de acordo com o relevo. A maior variabilidade espacial de atributos do solo e a produtividade da cultura de cana-de-açúcar ocorreram na parte mais baixa do talhão.1250125