RESUMO

In 1996, a diagnostic study performed in a 16-ha field located in Buenos Aires Province (Argentina), where a chemical industry produced 1,2,3,4,5,6-hexachlorocyclohexane (HCH) from 1960 to 1978, showed contamination with HCH ranging from 10 to 20,000 mg kg-1 dry soil (706.4 mg kg-1 average). For remediation purposes, a forestation plan was put into practice in 1997 employing approximately 12,300 Eucalyptus dunnii seedlings which by 2016 where fully grown into trees that formed a forest where local fauna can be found. Midterm analysis done in 2005, when E. dunnii trees had developed into 8-10 m high trees, indicated that HCH was incorporated into leaves and logs and soil phytoremediation was progressing. Final quantitation analysis of HCH in soil performed in 2016 demonstrated that the 97.2% of the field area was effectively decontaminated with 98.1% overall average efficiency. Thus, this work is the first global example of a successful employment of E. dunnii trees for HCH phytoremediation purposes at field scale. These results may encourage other researchers to test the ability of E. dunnii to phytoremediate soils contaminated with other chlorinated compounds like polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).

Assuntos

RESUMO

In oat production, tillering persistence is the determinant of one important yield component, namely the number of panicles. This process is highly influenced by the inter- and intraspecific interactions of the agroecosystem, which in turn depend on agronomic practices. The hypothesis of this research is that nitrogen does not increase oat tolerance to negative interference from trees, so oat tillering persistence in grain production remains un-modified by nitrogen at distances relative to the eucalyptus tracks, within the alley cropping agroforestry system (ACS). Thus, nitrogen should not be used to increase oat yield potential in these systems. The objective of this study was to determine how the tillering persistence for grain production and oat (Avena sativa L. cv. 'IPR 126') tiller traits were influenced by nitrogen levels (12 and 80kg N ha-1) at five equidistant positions between two adjacent eucalyptus (Eucalyptus dunnii Maiden) double line tracks [20m (4mx3m)] in ACS and traditional no-till agriculture in subtropical Brazil. The experiment was conducted in a split-block randomized block design with four replicates. The goal was to evaluate the oat phytomass, tiller-to-main shoot phytomass ratio, tillers per main shoot, grain yield and tiller-to-main shoot grain yield ratio. The oat tillering persistence for grain production is dependent on different nitrogen levels at distances relative to adjacent eucalyptus tracks and therefore, different nitrogen levels should be used in those areas, to improve oat yield potential inside ACS in subtropical Brazil.(AU)

Na produção de aveia, a persistência do perfilhamento é determinante para um importante componente de rendimento, o número de panículas. Esse processo é bastante influenciado pelas interações interespecíficas e intraespecíficas no agroecossistema, que, por sua vez, depende das práticas agronômicas. A hipótese deste trabalho é que o nitrogênio não aumenta a tolerância da aveia à interferência negativa das árvores, logo, a persistência do perfilhamento para produção de grãos não é modificada pelo nitrogênio em distâncias relativas às faixas de eucaliptos, em sistema agroflorestal em aleias (SAF). Assim, o nitrogênio não deve ser utilizado para aumentar o potencial de rendimento da aveia nestes sistemas. O objetivo deste trabalho foi determinar como a persistência do perfilhamento para produção de grãos e as características dos perfilhos da aveia (Avena sativa L. cv. 'IPR 126') são influenciados por níveis de nitrogênio (12 e 80kg N ha-1), em cinco posições equidistantes entre duas faixas adjacentes de linhas duplas [20m (4mx3m)] de eucalipto (Eucalyptus dunnii Maiden) e agricultura tradicional de plantio direto, no subtrópico brasileiro. O experimento foi realizado em faixas, no delineamento de blocos ao acaso, com quatro repetições. Foram avaliados a fitomassa da aveia, a razão de fitomassa entre o colmo principal e os perfilhos, o número de perfilhos por colmo principal, o rendimento de grãos e a relação do rendimento de grãos entre o colmo principal e os perfilhos. A persistência do perfilhamento para produção de grãos de aveia é dependente de diferentes níveis de nitrogênio em distâncias relativas a faixas adjacentes de eucaliptos, portanto, diferentes níveis de nitrogênio devem ser utilizados nessas distâncias, para aumentar o potencial de rendimento da aveia nos SAF no subtrópico brasileiro.(AU)

Assuntos

RESUMO

In oat production, tillering persistence is the determinant of one important yield component, namely the number of panicles. This process is highly influenced by the inter- and intraspecific interactions of the agroecosystem, which in turn depend on agronomic practices. The hypothesis of this research is that nitrogen does not increase oat tolerance to negative interference from trees, so oat tillering persistence in grain production remains un-modified by nitrogen at distances relative to the eucalyptus tracks, within the alley cropping agroforestry system (ACS). Thus, nitrogen should not be used to increase oat yield potential in these systems. The objective of this study was to determine how the tillering persistence for grain production and oat (Avena sativa L. cv. 'IPR 126') tiller traits were influenced by nitrogen levels (12 and 80kg N ha-1) at five equidistant positions between two adjacent eucalyptus (Eucalyptus dunnii Maiden) double line tracks [20m (4mx3m)] in ACS and traditional no-till agriculture in subtropical Brazil. The experiment was conducted in a split-block randomized block design with four replicates. The goal was to evaluate the oat phytomass, tiller-to-main shoot phytomass ratio, tillers per main shoot, grain yield and tiller-to-main shoot grain yield ratio. The oat tillering persistence for grain production is dependent on different nitrogen levels at distances relative to adjacent eucalyptus tracks and therefore, different nitrogen levels should be used in those areas, to improve oat yield potential inside ACS in subtropical Brazil.

Na produção de aveia, a persistência do perfilhamento é determinante para um importante componente de rendimento, o número de panículas. Esse processo é bastante influenciado pelas interações interespecíficas e intraespecíficas no agroecossistema, que, por sua vez, depende das práticas agronômicas. A hipótese deste trabalho é que o nitrogênio não aumenta a tolerância da aveia à interferência negativa das árvores, logo, a persistência do perfilhamento para produção de grãos não é modificada pelo nitrogênio em distâncias relativas às faixas de eucaliptos, em sistema agroflorestal em aleias (SAF). Assim, o nitrogênio não deve ser utilizado para aumentar o potencial de rendimento da aveia nestes sistemas. O objetivo deste trabalho foi determinar como a persistência do perfilhamento para produção de grãos e as características dos perfilhos da aveia (Avena sativa L. cv. 'IPR 126') são influenciados por níveis de nitrogênio (12 e 80kg N ha-1), em cinco posições equidistantes entre duas faixas adjacentes de linhas duplas [20m (4mx3m)] de eucalipto (Eucalyptus dunnii Maiden) e agricultura tradicional de plantio direto, no subtrópico brasileiro. O experimento foi realizado em faixas, no delineamento de blocos ao acaso, com quatro repetições. Foram avaliados a fitomassa da aveia, a razão de fitomassa entre o colmo principal e os perfilhos, o número de perfilhos por colmo principal, o rendimento de grãos e a relação do rendimento de grãos entre o colmo principal e os perfilhos. A persistência do perfilhamento para produção de grãos de aveia é dependente de diferentes níveis de nitrogênio em distâncias relativas a faixas adjacentes de eucaliptos, portanto, diferentes níveis de nitrogênio devem ser utilizados nessas distâncias, para aumentar o potencial de rendimento da aveia nos SAF no subtrópico brasileiro.

RESUMO

Muitas indústrias utilizam a combustão da biomassa vegetal para a geração de energia, processo que produz uma grande quantidade de cinza. O objetivo deste trabalho foi avaliar o efeito da aplicação de cinza de biomassa florestal como corretivo da acidez e fertilizante do solo, comparando-a com os efeitos do calcário dolomítico, em Cambissolo Húmico cultivado com Eucalyptus dunnii. O experimento foi conduzido em casa-de-vegetação em delineamento experimental inteiramente casualizado, com os tratamentos: 1- Testemunha; 2- Cinza de biomassa florestal na dose de 11Mg ha-1; 3- Cinza de biomassa florestal na dose de 22 Mg ha-1; 4- Calcário na dose de 8,5 Mg ha- 1; 5- Calcário na dose de 17 Mg ha-1. Foram plantadas, em vasos, mudas de Eucalyptus dunnii e cultivadas por 70 dias em casa de vegetação. Foram avaliados os atributos químicos e físicos do solo, a massa seca produzida e a composição química do tecido vegetal. A adição de cinza de biomassa florestal pode ser aplicada em solos altamente tamponados, pois não altera o grau de floculação da argila e a acidez do solo e é fonte de K, P e Ca. A aplicação de calcário dolomítico neutraliza a acidez do solo e disponibiliza mais P para o eucalipto. O crescimento inicial de plantas de eucalipto em solo adubado, não é alterado pela aplicação de cinza ou calcário.(AU)

Many industries use the biomass combustion for power generation, a process that produces a lot of ash. The objective of this study was to evaluate the effect of biomass combustion ash as a corrective for acidity and as a soil fertilizer, comparing it with the effects of lime, in the Humic Cambisol cultivated with Eucalyptus dunnii. The experiment was conducted in a greenhouse, in a completely randomized experimental design, with the following treatments: 1- control; 2- forest biomass ash at a dose of 11 Mg ha-1; 3- forest biomass ash of 22 Mg ha-1; 4- Lime at a dose of8.5 Mg ha-1; 5- Lime at a dose of17 Mg ha-1. Eucalyptus dunnii seedlings were planted in pots and cultivated for 70 days in a greenhouse. After the chemical and physical attributes of soil, dry mass produced and the chemical composition of plant tissue were evaluated. The addition of ash forest biomass can be used in highly buffered soils because: it does not alter the degree of fl occulation and the acidity of the soil; its a source of K, P and Ca. The application of lime neutralizes soil acidity and provides more P for the eucalyptus. The early growth of Eucalyptus in fertilized soil, is not changed by applying ashes or lime.(AU)

Assuntos

RESUMO

Muitas indústrias utilizam a combustão da biomassa vegetal para a geração de energia, processo que produz uma grande quantidade de cinza. O objetivo deste trabalho foi avaliar o efeito da aplicação de cinza de biomassa florestal como corretivo da acidez e fertilizante do solo, comparando-a com os efeitos do calcário dolomítico, em Cambissolo Húmico cultivado com Eucalyptus dunnii. O experimento foi conduzido em casa-de-vegetação em delineamento experimental inteiramente casualizado, com os tratamentos: 1- Testemunha; 2- Cinza de biomassa florestal na dose de 11Mg ha-1; 3- Cinza de biomassa florestal na dose de 22 Mg ha-1; 4- Calcário na dose de 8,5 Mg ha- 1; 5- Calcário na dose de 17 Mg ha-1. Foram plantadas, em vasos, mudas de Eucalyptus dunnii e cultivadas por 70 dias em casa de vegetação. Foram avaliados os atributos químicos e físicos do solo, a massa seca produzida e a composição química do tecido vegetal. A adição de cinza de biomassa florestal pode ser aplicada em solos altamente tamponados, pois não altera o grau de floculação da argila e a acidez do solo e é fonte de K, P e Ca. A aplicação de calcário dolomítico neutraliza a acidez do solo e disponibiliza mais P para o eucalipto. O crescimento inicial de plantas de eucalipto em solo adubado, não é alterado pela aplicação de cinza ou calcário.

Many industries use the biomass combustion for power generation, a process that produces a lot of ash. The objective of this study was to evaluate the effect of biomass combustion ash as a corrective for acidity and as a soil fertilizer, comparing it with the effects of lime, in the Humic Cambisol cultivated with Eucalyptus dunnii. The experiment was conducted in a greenhouse, in a completely randomized experimental design, with the following treatments: 1- control; 2- forest biomass ash at a dose of 11 Mg ha-1; 3- forest biomass ash of 22 Mg ha-1; 4- Lime at a dose of8.5 Mg ha-1; 5- Lime at a dose of17 Mg ha-1. Eucalyptus dunnii seedlings were planted in pots and cultivated for 70 days in a greenhouse. After the chemical and physical attributes of soil, dry mass produced and the chemical composition of plant tissue were evaluated. The addition of ash forest biomass can be used in highly buffered soils because: it does not alter the degree of fl occulation and the acidity of the soil; it’s a source of K, P and Ca. The application of lime neutralizes soil acidity and provides more P for the eucalyptus. The early growth of Eucalyptus in fertilized soil, is not changed by applying ashes or lime.

Assuntos

RESUMO

The utilization of rocks as fertilizers is limited by their low solubility. However, solubilization may be achieved by some micro-organisms, such as ectomycorrhizal fungi (ECMf). The aim of this study was to evaluate the potential of seven isolates of ECMf to solubilize two rocks, alkaline breccia and granite, and to liberate potassium and phosphorus for Eucalyptus dunnii seedlings under greenhouse conditions. Fungal inoculants were produced in a peat-vermiculite-liquid medium mixture and added to the planting substrate at 10 percent. Rocks were ground up and added at 0.500 mg and 16.0 mg per plant, as a source of phosphorus and potassium, respectively. Other nutrients were added and E. dunnii seeds were sown. Control plants, non-inoculated, were fertilized with the same amount of phosphorus and potassium using soluble forms. After 90 days, the plant height, shoot dry weight, root length, phosphorus and potassium contents, and mycorrhizal colonization were evaluated. Alkaline breccia was more efficient than granite as a source of phosphorus and potassium for the plants, and may be an alternative to conventional fertilizers. Isolates UFSC-Pt22 (Pisolithus sp.) and UFSC-Pt186 (Pisolithus microcarpus) were the most efficient in promoting plant growth, mainly when combined with alkaline breccia to replace potassium and phosphorus fertilizers, respectively.

Assuntos

RESUMO

The utilization of rocks as fertilizers is limited by their low solubility. However, solubilization may be achieved by some micro-organisms, such as ectomycorrhizal fungi (ECMf). The aim of this study was to evaluate the potential of seven isolates of ECMf to solubilize two rocks, alkaline breccia and granite, and to liberate potassium and phosphorus for Eucalyptus dunnii seedlings under greenhouse conditions. Fungal inoculants were produced in a peat-vermiculite-liquid medium mixture and added to the planting substrate at 10 %. Rocks were ground up and added at 0.500 mg and 16.0 mg per plant, as a source of phosphorus and potassium, respectively. Other nutrients were added and E. dunnii seeds were sown. Control plants, non-inoculated, were fertilized with the same amount of phosphorus and potassium using soluble forms. After 90 days, the plant height, shoot dry weight, root length, phosphorus and potassium contents, and mycorrhizal colonization were evaluated. Alkaline breccia was more efficient than granite as a source of phosphorus and potassium for the plants, and may be an alternative to conventional fertilizers. Isolates UFSC-Pt22 (Pisolithus sp.) and UFSC-Pt186 (Pisolithus microcarpus) were the most efficient in promoting plant growth, mainly when combined with alkaline breccia to replace potassium and phosphorus fertilizers, respectively.

RESUMO

The utilization of rocks as fertilizers is limited by their low solubility. However, solubilization may be achieved by some micro-organisms, such as ectomycorrhizal fungi (ECMf). The aim of this study was to evaluate the potential of seven isolates of ECMf to solubilize two rocks, alkaline breccia and granite, and to liberate potassium and phosphorus for Eucalyptus dunnii seedlings under greenhouse conditions. Fungal inoculants were produced in a peat-vermiculite-liquid medium mixture and added to the planting substrate at 10 %. Rocks were ground up and added at 0.500 mg and 16.0 mg per plant, as a source of phosphorus and potassium, respectively. Other nutrients were added and E. dunnii seeds were sown. Control plants, non-inoculated, were fertilized with the same amount of phosphorus and potassium using soluble forms. After 90 days, the plant height, shoot dry weight, root length, phosphorus and potassium contents, and mycorrhizal colonization were evaluated. Alkaline breccia was more efficient than granite as a source of phosphorus and potassium for the plants, and may be an alternative to conventional fertilizers. Isolates UFSC-Pt22 (Pisolithus sp.) and UFSC-Pt186 (Pisolithus microcarpus) were the most efficient in promoting plant growth, mainly when combined with alkaline breccia to replace potassium and phosphorus fertilizers, respectively.

RESUMO

This study has been carried out to define total bulk volume equations for Eucalyptus dunni Maiden, 6.5 years old, lined up along a 3 by 2 meter-spaced planted setting. These equations were supposed to both trees with and without bark. Eighty trees were cubed by Smalian's method distributed according to diameter classes and following a proportional way, over four forest sites. Equations were determinated through stepwise regression procedure, following an independent process for each site. A second step was evaluate the possiblility of these equations to be reduced into a single one. The covariance analysis applied to data showed the possibility of using an unique one equation to estimate the tree bulk volume to the region. Two equations were selected: one to calculate the total volume of trees with bark and another to determine the commercial volume without bark. The equation tom determine total volume was equal to: log v = -9.06566 + 0.93016 . log(d²h) and the equation to determine comercial volume was equal to: log v = -14.14078 + 1.39608 . log(d²h). Besides, no differences in the trunk shape and, consequently, in the bulk volume of trees in the four sites studied were observed.

O estudo foi realizado para definir equações de volume total com casca e comercial sem casca para Eucalyptus dunnii Maiden, na idade de 6,5 anos, implantado em espaçamento 3 x 2m. Foram cubadas, pelo método de Smaliam, 80 árvores distribuídas em classe diamétrica e de forma proporcional em quatro hortos florestais. As equações de volume total com casca e comercial sem casca foram determinadas através do procedimento "stepwise" de regressão, de forma independente, para cada local e, posteriormente, foi estudada a possibilidade de agrupamento destas equações em um modelo único. A análise de covariância aplicada aos dados indicou a possibilidade do emprego de uma única equação para estimar o volume da espécie em toda a região. Selecionou-se pelo alto coeficiente de determinação e baixo erro padrão da estimativa a equação log v = - 9,06566 + 0,93016 . log(d² h) para o volume total com casca e log v = -14,14078 + 1,39608 . log(d² h) para o volume comercial sem casca. Além disso, não observou-se diferenças na forma do tronco e por conseqüência no volume das árvores nos quatro locais estudados.

RESUMO

This study has been carried out to define total bulk volume equations for Eucalyptus dunni Maiden, 6.5 years old, lined up along a 3 by 2 meter-spaced planted setting. These equations were supposed to both trees with and without bark. Eighty trees were cubed by Smalian's method distributed according to diameter classes and following a proportional way, over four forest sites. Equations were determinated through stepwise regression procedure, following an independent process for each site. A second step was evaluate the possiblility of these equations to be reduced into a single one. The covariance analysis applied to data showed the possibility of using an unique one equation to estimate the tree bulk volume to the region. Two equations were selected: one to calculate the total volume of trees with bark and another to determine the commercial volume without bark. The equation tom determine total volume was equal to: log v = -9.06566 + 0.93016 . log(d²h) and the equation to determine comercial volume was equal to: log v = -14.14078 + 1.39608 . log(d²h). Besides, no differences in the trunk shape and, consequently, in the bulk volume of trees in the four sites studied were observed.

O estudo foi realizado para definir equações de volume total com casca e comercial sem casca para Eucalyptus dunnii Maiden, na idade de 6,5 anos, implantado em espaçamento 3 x 2m. Foram cubadas, pelo método de Smaliam, 80 árvores distribuídas em classe diamétrica e de forma proporcional em quatro hortos florestais. As equações de volume total com casca e comercial sem casca foram determinadas através do procedimento "stepwise" de regressão, de forma independente, para cada local e, posteriormente, foi estudada a possibilidade de agrupamento destas equações em um modelo único. A análise de covariância aplicada aos dados indicou a possibilidade do emprego de uma única equação para estimar o volume da espécie em toda a região. Selecionou-se pelo alto coeficiente de determinação e baixo erro padrão da estimativa a equação log v = - 9,06566 + 0,93016 . log(d² h) para o volume total com casca e log v = -14,14078 + 1,39608 . log(d² h) para o volume comercial sem casca. Além disso, não observou-se diferenças na forma do tronco e por conseqüência no volume das árvores nos quatro locais estudados.