Atributos físico-hídricos de um latossolo de cerrado em diferentes posições de amostragem na lavoura cafeeira

Self Cite

SUMMARYIn modern agriculture, several factors cause changes in the soil physical properties. The time of establishment of a crop (plantation age) and the slope are examples of factors that moderate the impact of mechanized operations on the soil structure. The objective of this study was to analyze the effect of machinery traffic on the physical properties of a Red-Yellow Latosol under coffee plantations with different ages (2, 7, 18, and 33 years) and slope positions (3, 9 and 15 %). Samples were collected from three positions between coffee rows (lower wheel track, interrow and upper wheel track) and at two depths (surface layer and sub-surface). Changes in the total porosity, macroporosity, microporosity, organic matter, bulk density, and aggregate stability were investigated. Our results showed that the slope influenced the organic matter content, microporosity and aggregate stability. The soil samples under the inter-row were minimally damaged in their structure, compared to those from under the lower and upper wheel track, while the structure was better preserved under the lower than the upper track. The time since the establishment of the crop, i.e., the plantation age, was the main factor determining the extent of structural degradation in the coffee plantation.Index terms: agricultural traffic, Coffea arabica L., soil degradation, aggregate stability.( Vários fatores causam alterações nas propriedades físicas do solo na agricultura moderna. O tempo de cultivo da cultura e a inclinação da área cultivada são exemplos de fatores que podem influenciar, bem como prejudicar, a estrutura do solo. O objetivo deste estudo foi analisar em plantações de café com diferentes idades de cultivo e com diferentes declividades na entrelinha, o efeito do tráfego de máquinas sobre as propriedades físicas do solo. O estudo foi desenvolvido em um Latossolo Vermelho-Amarelo. Selecionaram-se plantações de café com tempos de cultivo de 2, 7, 18 e 33 anos. Nessas plantações, foram selecionadas áreas (entrelinha do café) com inclinação lateral de 3, 9 e 15 %. O solo foi amostrado em três posições na entrelinha do café: linha de tráfego de baixo, linha de tráfego de cima e entre as linhas de tráfego (entrelinha). Amostras de solo foram coletadas em duas camadas (superficial e subsuperficial). As propriedades investigadas foram: porosidade total, macroporosidade, microporosidade, matéria orgânica, densidade e estabilidade de agregados. A declividade da entrelinha do cafeeiro influenciou a matéria orgânica e algumas propriedades físicas do solo, como microporosidade e estabilidade de agregados. As amostras na entrelinha (entre as linhas de tráfego) foram as que apresentaram os melhores resultados em termos de preservação da estrutura do solo, em relação às amostras das linhas de tráfegos (de baixo e de cima); as amostras da linha de tráfego de baixo evidenciaram melhores resultados em termos de preservação da estrutura do solo do que a linha de tráfego de cima. Observou-se que o tempo de cultivo da cultura foi o principal fator que ...

Section: Resultscontrasting

confidence: 99%

“…Soil compaction induced by high traffic intensity can damage the soil structure, thereby reducing the potential yield of coffee plantations (Gontijo et al, 2008). Several soil-dependent conditions can exacerbate the changes in soil physical properties due to agricultural traffic.…”

Section: Introductionmentioning

confidence: 99%

Influence of field slope and coffee plantation age on the physical properties of a red-yellow Latosol

Iori

Dias

Ajayi

et al. 2014

Self Cite

“…The results of Martínez et al (2010b) indicate the suitability of SOILPAR 2.00 to obtain PWP estimates for the study area by two approaches: i) using values obtained from PP with the 'EPIC' method (Erosion Productivity Impact Calculator) (Izaurralde et al, 2001) (r 2 =0.79) or ii) using values obtained by WAM with the 'Mayr-Jarvis' method (Mayr & Jarvis, 1999) (r 2 =0.81). The following PTFs were analysed: i) the PTF1 proposed by Soto et al (2001) for the region of Galicia (r 2 =0.65) and ii) PTFs specific to the study area for different categories (soil type, crop and sampling depth) (Martínez, 2008) (Table 3).…”

Section: Methods Used To Determine Soil Hydraulic Propertiesmentioning

confidence: 98%

“…In the context of water resource management, various methods have been used to obtain or determine soil hydraulic properties, particularly hydrolimits (Štekauerová et al, 2002) or hydro-physical limits (Oliveira et al, 2004;Gontijo et al, 2008) from properties that can be easily measured and quantified. Such methods facilitate and shorten the measurement process.…”

Section: Introductionmentioning

confidence: 99%

The efficiency of different estimation methods of hydro-physical limits

Martínez¹,

García²,

Cancela³

2012

SUMMARYThe soil water available to crops is defined by specific values of water potential limits. Underlying the estimation of hydro-physical limits, identified as permanent wilting point (PWP) and field capacity (FC), is the selection of a suitable method based on a multi-criteria analysis that is not always clear and defined. In this kind of analysis, the time required for measurements must be taken into consideration as well as other external measurement factors, e.g., the reliability and suitability of the study area, measurement uncertainty, cost, effort and labour invested. In this paper, the efficiency of different methods for determining hydro-physical limits is evaluated by using indices that allow for the calculation of efficiency in terms of effort and cost. The analysis evaluates both direct determination methods (pressure plate -PP and water activity meter -WAM) and indirect estimation methods (pedotransfer functions -PTFs). The PTFs must be validated for the area of interest before use, but the time and cost associated with this validation are not included in the cost of analysis. Compared to the other methods, the combined use of PP and WAM to determine hydro-physical limits differs significantly in time and cost required and quality of information. For direct methods, increasing sample size significantly reduces cost and time. This paper assesses the effectiveness of combining a general analysis based on efficiency indices and more specific analyses based on the different influencing factors, which were considered separately so as not to mask potential benefits or drawbacks that are not evidenced in efficiency estimation.Index terms: field capacity, permanent wilting point, pedotransfer functions, water activity meter.(1) Received for publication in January 24, 2011 and approved in September 25, 2012.

“…As a consequence, macroporosity and total porosity (as well as θ s ) decrease and bulk density increases. Cryptopores and micropores (and θ r ) are very little affected by the process, and there may even be a small increase in their content (SiegelIssem et al, 2005;Pengthamkeerati et al, 2006;Beutler et al, 2007;Gontijo et al, 2008).…”

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.