O relevo na interpretação da variabilidade espacial dos teores de nutrientes em folha de citros

Leão, Marisol G. A. de; Marques, José Carlos; Souza, Zigomar Menezes de; Siqueira, Diego Silva; Pereira, Gener Tadeu

doi:10.1590/s1415-43662010001100004

Cited by 7 publications

(4 citation statements)

References 15 publications

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“…Worsham et al (2010) also found that semivariograms fit to these two models when the carbon and N levels in the plant litter were studied under different forest cover. Some studies show that the levels of mineral nutrients in the tissue of the plants usually fit to spherical and exponential models (VIEIRA et al, 2010;LEÃO et al, 2010;CAVALCANTE et al, 2011;RODRIGUES JÚNIOR et al, 2011). The fitted models exhibited high determination coefficients (R 2 ) that ranged from 0.92 to 0.99 and low squared residual sums (SRSs) ( Table 3).…”

Section: A Coefficient Of Variation Lower Than 35%mentioning

confidence: 99%

Integrating forest-pasture: Spatial analysis and delineation of zones of litter production and nutrient return

Neto

Santos

Leite

et al. 2015

SCA

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This study aimed to quantify, describe, and identify plant litter production and nutrient accumulation zones in different forest-pasture integration (FPI) systems and forest strata of the Cerrado-Amazon transition on typical orthic Quartzarenic Neosol using spatial analysis, principal component analysis, and non-hierarchical fuzzy k-mean clustering logic techniques. The evaluations were performed at two FPI systems comprising a combination of Brachiaria brizantha cv. Marandu and thinned native vegetation with 50 and 75% (FPI-I and FPI-II, respectively) shade in an original thinned forest (NF-I) and in an original intact forest (NF-II) with 80 and 95% shade, respectively. An area of 4,000 m² (40 x 100 m) that contained 32 sampling points arranged in a 4 x 25 m grid was demarcated for each treatment. Plant litter was collected using 32 collectors installed at equidistant points. Twelve nylon bags were placed on the soil surface at each point to evaluate the plant litter decomposition, totaling 384 bags per treatment. It was possible to quantify, describe, and define plant litter production and nutrient accumulation zones in different FPI systems and forest strata of the Cerrado-Amazon transition on orthic Quartzarenic Neosol using geostatistical analysis, principal components, and non-hierarchical fuzzy k-mean clustering logic procedures. Key words: Precision agriculture, principal component analysis, geostatistics, ordinary kriging, fuzzy k-mean logic, soil management, special variability ResumoO objetivo foi quantificar, descrever e identificar zonas de produção de serapilheira e acúmulo de nutrientes em diferentes sistemas de integração floresta-pasto e estratos de floresta de transição CerradoAmazônia sobre Neossolo Quartzarênico Órtico típico, utilizando técnicas de análise espacial, de análise de componentes principais e da lógica de agrupamento não hierárquica de fuzzy k-médias. As avaliações foram realizadas em dois sistemas de integração floresta-pasto originários da associação de Brachiaria brizantha cv. Marandu e vegetação nativa raleada com 50% e 75% (IFP-I e IFP-II, respectivamente) de sombreamento numa floresta original raleado (FN-I) e em floresta original intacta (FN-II) com 80%

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Section: A Coefficient Of Variation Lower Than 35%mentioning

confidence: 99%

Integrating forest-pasture: Spatial analysis and delineation of zones of litter production and nutrient return

Neto

Santos

Leite

et al. 2015

SCA

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“…When studying morphological components of Marandu grass in places with different levels of pasture degradation, Silva Neto et al (2012) found that the values fitted spherical and exponential semivariogram models. Some studies have shown that mineral nutrient concentrations in the tissue of plants commonly fit spherical and exponential models (VIEIRA et al, 2010;LEÃO et al, 2010;CAVALCANTE et al, 2011;RODRIGUES JÚNIOR et al, 2011). The fitted models showed high coefficients of determination (R 2 ), ranging from 0.80 to 0.99, and low residual sums of square (SS r ).…”

Section: Coefficients Of Variation Lower Than 35%mentioning

confidence: 99%

Spatial variation and area definition of nutrient extraction by Marandu grass biomass

et al. 2015

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ResumoO objetivo foi quantificar, descrever e identificar zonas de extração de nutrientes pela fitomassa da Brachiaria brazantha cv. Marandu em sistemas de integração floresta-pasto em região de transição Cerrado-Amazônia sobre Neossolo Quartzarênico Órtico típico, por meio de técnicas de geoestatística, de análise de componentes principais e da lógica de agrupamento não hierárquica de fuzzy k-médias. As avaliações foram realizadas em dois sistemas de integração floresta-pasto originários da associação de Brachiaria brizantha cv. Marandu e vegetação nativa raleada com 50% e 75% (IFP-I e IFP-II, respectivamente) de sombreamento e em pastagem de Brachiaria brizantha cv. Marandu em monocultivo. Para cada tratamento foi demarcada uma área de 4.000 m² (40 x 100 m) que continham 32 pontos de coleta dispostos em malha de 4 x 25 m. Em cada ponto previamente marcado nos tratamentos avaliados se estimou as taxas de alongamento de lâminas foliares, senescência foliar e de alongamento de colmo. Ao final de cada ciclo produtivo foram determinados nas lâminas foliares e no colmo os teores de nutrientes (N, P, K, Ca e Mg. A extração de nutrientes foi calculada em função das taxas de produção bruta de forragem, de acúmulo de forragem e de folhas. Zonas de extração de nutrientes minerais pela fitomassa da Brachiaria brizantha cv. Marandu são definidas utilizando-se técnicas de geoestatística, de análise de componentes principais e da lógica de agrupamento não hierárquica de fuzzy k-médias. Assim o uso desses procedimentos é viável na definição e delimitação de zonas homogêneas dentro e entre os sistemas de produção de gramínea estudados. Palavras-chave: Agropecuária de precisão, análise componentes principais, geoestatística, krigagem ordinária, lógica fuzzy k-médias, manejo da pastagem AbstractThe present study aimed to quantify, describe and identify areas of nutrient extraction by Brachiaria brizantha cv. Marandu biomass in integrated forest-pasture systems from a Cerrado-Amazon transition region with Typic Quartzipsamment soil by using geostatistical techniques, principal components analysis and non-hierarchical fuzzy k-means clustering. The evaluations were conducted in two integrated forest-pasture systems from an association with Brachiaria brizantha cv. vegetation thinned with 50% and 75% (integrated forest production-I (IFP-I) and IFP-II, respectively) shading and in Brachiaria brizantha cv. Marandu monoculture. For each treatment, an area of 4,000 m² (40 x 100 m) was demarcated containing 32 collection points arranged in a 4 x 25 m mesh. At each point, the rates of leaf elongation, senescence and stem elongation were estimated. At the end of each production cycle, the nutrient content (N, P, K, Ca and Mg) was determined in the leaf blades and stem. The nutrient uptake was calculated according to the rates of gross forage production, forage accumulation and leaf accumulation. The nutrient extraction zones of Brachiaria brizantha cv. Marandu biomass were defined using geostatistical techniques, principal components analy...

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Section: Coefficients Of Variation Lower Than 35%mentioning

confidence: 99%

Spatial variation and area definition of nutrient extraction by Marandu grass biomass

et al. 2015

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The present study aimed to quantify, describe and identify areas of nutrient extraction by Brachiaria brizantha cv. Marandu biomass in integrated forest-pasture systems from a Cerrado-Amazon transition region with Typic Quartzipsamment soil by using geostatistical techniques, principal components analysis and non-hierarchical fuzzy k-means clustering. The evaluations were conducted in two integrated forest-pasture systems from an association with Brachiaria brizantha cv. Marandu and native vegetation thinned with 50% and 75% (integrated forest production-I (IFP-I) and IFP-II, respectively) shading and in Brachiaria brizantha cv. Marandu monoculture. For each treatment, an area of 4,000 m² (40 x 100 m) was demarcated containing 32 collection points arranged in a 4 x 25 m mesh. At each point, the rates of leaf elongation, senescence and stem elongation were estimated. At the end of each production cycle, the nutrient content (N, P, K, Ca and Mg) was determined in the leaf blades and stem. The nutrient uptake was calculated according to the rates of gross forage production, forage accumulation and leaf accumulation. The nutrient extraction zones of Brachiaria brizantha cv. Marandu biomass were defined using geostatistical techniques, principal components analysis and non-hierarchical fuzzy k-means clustering. Thus, the use of these procedures is feasible for the definition and delimitation of homogeneous zones within and between the pasture production systems studied.

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O relevo na interpretação da variabilidade espacial dos teores de nutrientes em folha de citros

Cited by 7 publications

References 15 publications

Integrating forest-pasture: Spatial analysis and delineation of zones of litter production and nutrient return

Integrating forest-pasture: Spatial analysis and delineation of zones of litter production and nutrient return

Spatial variation and area definition of nutrient extraction by Marandu grass biomass

Spatial variation and area definition of nutrient extraction by Marandu grass biomass

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