Qualidade física de três solos sob colheita mecanizada de cana-de-açúcar

SUMMARYThe cultivation of sugarcane with intensive use of machinery, especially for harvest, induces soil compaction, affecting the crop development. The control of agricultural traffic is an alternative of management in the sector, with a view to preserve the soil physical quality, resulting in increased sugarcane root growth, productivity and technological quality. The objective of this study was to evaluate the physical quality of an Oxisol with and without control traffic and the resulting effects on sugarcane root development, productivity and technological quality. The following managements were tested: no traffic control (NTC), traffic control consisting of an adjustment of the track width of the tractor and sugarcane trailer (TC1) and traffic control consisting of an adjustment of the track width of the tractor and trailer and use of an autopilot (TC2). Soil samples were collected (layers 0. 00-0.10; 0.10-0.20 and 0.20-0.30 m) in the plant rows, inter-row center and seedbed region, 0.30 m away from the plant row. The productivity was measured with a specific weighing scale. The technological variables of sugarcane were measured in each plot. Soil cores were collected to analyze the root system. In TC2, the soil bulk density and compaction degree were lowest and total porosity and macroporosity highest in the plant row. Soil penetration resistance in the plant row, was less than 2 MPa in TC1 and TC2. Soil aggregation and total organic carbon did not differ between the management systems. The root surface and volume were increased in TC1 and TC2, with higher productivity and sugar yield than under NTC. The sugarcane variables did not differ between the managements. O cultivo do canavial com uso intenso de máquinas, principalmente na colheita, resulta na compactação do solo, o que influencia no desenvolvimento da cultura. O manejo com controle de tráfego agrícola representa uma alternativa ao setor, podendo preservar a qualidade física do solo, resultando em maior crescimento radicular, produtividade e qualidade da cana. Objetivou-se com este trabalho avaliar a qualidade física de um Latossolo Vermelho com e sem controle de tráfego agrícola e seu efeito no desenvolvimento radicular, na produtividade e na qualidade tecnológica da cana-de-açúcar. Os manejos avaliados foram: testemunha sem controle de tráfego (NTC), controle de tráfego com ajuste da bitola do trator e do transbordo de cana colhida (TC1) e controle de tráfego com ajuste da bitola e uso de piloto automático (TC2). Amostras de solo foram coletadas nas camadas 0,00-0,10; 0,10-0,20; e 0,20-0,30 m nas linhas de plantio e do rodado (entrelinha) e na região do canteiro, distante 0,30 m da linha de plantio. A produtividade foi medida com balança específica para transbordo. As variáveis tecnológicas da cana foram medidas em cada parcela. Os monólitos de solo foram coletados para análise do sistema radicular. O TC2 apresentou menor densidade e grau de compactação e maior porosidade total e macroporosidade na linha de plantio. A resistência do solo à pe...

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of traffic control on the soil physical quality and the cultivation of sugarcane

Souza

Silva

et al. 2014

“…The LLWR concept is increasingly applied to sugarcane cultivation, and recent studies that modeled soil compaction in cane fields have helped to minimize the impacts of compaction on the structure of soils planted to sugarcane (Severiano et al, 2009;Silva et al, 2009;Cavalieri et al, 2011;Roque et al, 2011). However, there has been little study of the effects of soil structural degradation on the yield and quality for industrial processing of subsequent crops as well as its effect on the growth of sugarcane cultivars with different maturation cycles.…”

Section: Introductionmentioning

confidence: 99%

Least limiting water range in assessing compaction in a Brazilian Cerrado latosol growing sugarcane

Gonçalves

Severiano

Silva

et al. 2014

SUMMARYIn the south-central region of Brazil, there is a trend toward reducing the sugarcane inter-harvest period and increasing traffic of heavy harvesting machinery on soil with high water content, which may intensify the compaction process. In this study, we assessed the structural changes of a distroferric Red Latosol (Oxisol) by monitoring soil water content as a function of the Least Limiting Water Range (LLWR) and quantified its effects on the crop yield and industrial quality of the first ratoon crop of sugarcane cultivars with different maturation cycles. Three cultivars were subjected to four levels of soil compaction brought about by a differing number of passes of a farm tractor (T 0 = soil not trafficked, T 2 = 2 passes, T 10 = 10 passes, and T 20 = 20 passes of the tractor in the same place) in a 3 × 4 factorial arrangement with three replications. The deleterious effects on the soil structure from the farm machinery traffic were limited to the surface layer (0-10 cm) of the interrow area of the ratoon crop. The LLWR dropped to nearly zero after 20 tractor passes between the cane rows. We detected differences among the cultivars studied; cultivar RB 86-7515 stood out for its industrial processing quality, regardless of the level of soil compaction. Monitoring of soil moisture in the crop showed exposure to water stress conditions, although soil compaction did not affect the production variables of the sugarcane cultivars. We thus conclude that the absence of traffic on the plant row maintained suitable soil conditions for Na região centro-sul do Brasil, há a tendência de redução do período de entressafra canavieira, condicionando tráfego de máquinas para colheita em condições de elevados conteúdos de água do solo, o que pode contribuir para a intensificação do processo de compactação. Os objetivos deste estudo foram avaliar as alterações estruturais de um Latossolo Vermelho distroférrico por meio do monitoramento do conteúdo de água do solo em razão do Intervalo Hídrico Ótimo (IHO) e quantificar seus efeitos sobre o rendimento agrícola e o industrial da primeira soqueira de cultivares de cana-de-açúcar, com diferentes ciclos de maturação. Foram avaliados três cultivares de cana-de-açúcar (RB 83-5054; RB 84-5210; e RB 86-7515) submetidos a quatro níveis de compactação do solo, atingidos pelo número de passadas de um trator agrícola, correspondendo a T 0 = solo não trafegado; T 2 = 2; T 10 = 10; e T 20 = 20 passadas do trator no mesmo lugar, em esquema fatorial 3 × 4, com três repetições. Os efeitos deletérios causados na estrutura do solo pelo tráfego de maquinário agrícola ficaram limitados à entrelinha de cultivo das soqueiras, na camada superficial do solo. O IHO foi reduzido a valores próximos de zero com 20 passadas do trator, nas entrelinhas de cultivo da cana-de-açúcar. Foi detectada diferença entre os cultivares estudados, com destaque para o RB 86-7515, quanto à qualidade tecnológica da matéria-prima, independentemente dos níveis de compactação do solo a que estiveram sujeitos. O monitoram...

“…These two examples corroborate the observation about "individual soils" by Dexter (2004a) and show that S is not an absolute indicator of soil physical quality. It is, therefore, questionable whether anything can be inferred based on the value of S alone, even if this is common practice in many publications (Calonego & Rosolem, 2011;Cavalieri et al, 2011) Evaluation of soil quality depends on understanding the insertion of soil in the landscape-soil-plantatmosphere system; therefore, it depends on knowledge of how the system functions and the underlying physical, chemical and biological processes. We mentioned in the Introduction that process-based models capable of simulating these processes applied to agronomy, hydrology, ecology and meteorology are being developed by specific research groups and are available to the scientific community.…”

Section: S Versus Relative Densitymentioning

confidence: 99%

Revisiting the S-index for soil physical quality and its use in Brazil

Lier

2014

SUMMARYThe S-index was introduced in 2004 in a publication by A.R. Dexter. S was proposed as an indicator of soil physical quality. A critical value delimiting soils with rich and poor physical quality was proposed. At present, Brazil is world leader in citations of Dexter´s publication. In this publication the S-theory is mathematically revisited and extended. It is shown that S is mathematically correlated to bulk density and total porosity. As an absolute indicator, the value of S alone has proven to be incapable of predicting soil physical quality. The critical value does not always hold under boundary conditions described in the literature. This is to be expected because S is a static parameter, therefore implicitly unable to describe dynamic processes. As a relative indicator of soil physical quality, the S-index has no additional value over bulk density or total porosity. Therefore, in the opinion of the author, the fact that bulk density or total porosity are much more easily determined than the water retention curve for obtaining S disqualifies S as an advantageous indicator of relative soil physical quality. Among the several equations available for the fitting of water retention curves, the Groenevelt-Grant equation is preferable for use with S since one of its parameters and S are linearly correlated. Since efforts in soil physics research have the purpose of describing dynamic processes, it is the author´s opinion that these efforts should shift towards mechanistic soil physics as opposed to the search for empirical correlations like S which, at present, represents far more than its reasonable share of soil physics in Brazil.