Estoque de carbono nos biomas brasileiros com enfoque no cerrado e no cultivo de eucalipto no Mato Grosso do Sul
Data
2022-08-19
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A presença de carbono orgânico no solo e na biomassa vegetal é benéfica para as funções dos ecossistemas e está intimamente associada à redução dos efeitos negativos das mudanças climáticas. Os estoques de carbono do solo são controlados por uma variedade de fatores climáticos e biogeoquímicos, sendo diretamente influenciados por mudanças no uso e ocupação do solo, em particular pela conversão de ecossistemas naturais em áreas cultivadas para agricultura e pecuária. Deste modo, objetivou-se com este trabalho estudar a presença de carbono orgânico no solo e os fatores que podem promover alteração no seu estoque (EstC). Para avaliar tais fatores, este trabalho foi dividido em três capítulos: No capítulo 1, foi realizado um estudo a partir de dados amostrais e resultados de simulações de estoque de carbono no solo, em seis biomas brasileiros (Cerrado, Amazônia, Pantanal, Caatinga, Mata-atlântica e Pampas), bem como verificar a contribuição dos fatores Bioma, Sistemas de uso do solo, Profundidade amostrada e o Tipo de dado (amostrado ou simulado) sobre o estoque de carbono dos solos. Apenas 42 trabalhos em mais de 200 artigos científicos foram qualificados para este estudo. Para analisar os dados, procedeu-se a análise de variância (ANOVA) seguindo o delineamento inteiramente casualizado, em esquema fatorial, cujos fatores analisados foram o uso da terra, a camada do solo (0,0 – 0,10 e 0,0 – 0,20 m), o bioma e a interação entre eles, aplicando-se o teste F a 5% de probabilidade para detectar as diferenças dos fatores e a interação entre eles, e o teste de Scott-Knott a 5% foi utilizado para detectar diferenças entre as médias. Complementar à ANOVA, foi aplicada uma técnica com base na análise de componentes principais (CP), com o intuito de verificar a contribuição dos fatores de estudo analisados no EstC. Nos estoques de carbono amostrados de 0,0 – 0,20 m, houve diferença significativa no Bioma Pantanal, com estoques inferiores aos demais biomas na vegetação nativa bem como na pastagem, na interação uso da terra x Bioma Pampas. Nos dados simulados de 0,0 – 0,20 m foram observadas diferenças significativas para Mata Atlântica e Pantanal, com valores acima de 43 Mg ha-1, e para uso da terra na pastagem o estoque de pastagens do Pantanal foram obtidos os menores valores. Por meio da técnica CP, foi possível observar que o EstC se correlaciona com as práticas de conservação, permitindo inferir que as práticas agrícolas influenciam o estoque de carbono. No Capítulo 2, foi verificado o EstC em diferentes áreas de cultivo localizadas no Sudeste do Mato Grosso do Sul: pastagem degradada, cerrado natural e áreas de plantio de eucalipto em diferentes estádios de desenvolvimento (3, 5, 7, 10 e 14 anos) com coletas de solo realizadas nas linhas e entrelinhas de plantio. Os dados obtidos foram analisados quanto a estatística descritiva e análise de variância (ANOVA), que seguiu o delineamento em blocos casualizados, em esquema fatorial (5 x 2 + 2) com 4 repetições, sendo cinco anos de plantio de eucalipto (3, 5, 7, 10 e 14 anos), duas posições (linha e entrelinha) e dois tratamentos adicionais (cerrado e pastagem) em quatro profundidades (0,0 – 0,10, 0,10 – 0,30, 0,30 – 0,60 e 0,60 – 1,00 m). O teste F foi utilizado para detectar as diferenças dos fatores e das interações, o teste de Tukey para detectar as diferenças entre as médias dos anos de cultivo e o teste de Dunnett para comparações entre essas médias com as médias das testemunhas e entre testemunhas. Na análise do EstC as diferenças significativas de destaque foram encontradas na profundidade 0,30 – 0,60 m no ano 14, na entrelinha, para eucalipto (9,99 ± 0,89 Mg ha-1), Cerrado (9,88 ± 0,62 Mg ha-1) e pastagem (10,96 ± 0,87 Mg ha-1) e na profundidade 0,60 – 1,00 m no ano 14, na linha, para eucalipto (11,04 ± 0,96 Mg ha-1), Cerrado (14,47 ± 0,60 Mg ha-1) e pastagem (15,19 ± 1,37 Mg ha-1). Com base na análise dos dados ficou evidenciado que a preservação do Cerrado mantém o Carbono no solo e que no final dos ciclos do Eucalipto (7 e 14 anos) os valores estão próximos ao encontrado no Cerrado. Por fim, no Capítulo 3 foi avaliada a medição da resistência do solo à penetração (RP) por três metodologias a partir do penetrógrafo manual de molas (SC60), penetrômetro estático de bancada com 60 cm.c.a-coluna d’água (PEB60) e penetrômetro estático de bancada com 100 cm.c.a (PEB100), em 3 áreas de cultivo (eucalipto - EUCP, pastagem - PAST e cerrado conservado – CERC), em 3 profundidades (0 – 0,10; 0,10 – 0,30 e 0,30 – 0,60 m). Os dados obtidos foram convertidos para MPa (para resistência do solo à penetração), analisados quanto a estatística descritiva e análise de variância, sendo o teste F utilizado para detectar as diferenças dos fatores e as interações, e o teste Tukey para comparar as médias quando encontradas diferenças significativas. Foram verificados valores de RP acima de 1,9 MPa com o uso do SC-60 no eucalipto e na pastagem. Foram constatados valores de RP superiores, para pastagem nas profundidades de 0,10 – 0,30 m (1,50 Mpa), no SC60 em cultivo de eucalipto e pastagem (1,90 Mpa) e SC60 a partir da profundidade de 0,10 – 0,30 m (1,75 a 2,07 Mpa), valores considerados moderados e não impeditivos ao desenvolvimento radicular do eucalipto. O SC60 apresentou os maiores valores de RP (1,16 a 2,07 Mpa) independente do cultivo e da profundidade. Não houve variações significativas na RP em relação às colunas d’água utilizadas (60 e 100 cm.c.a.). Palavras-chave: uso do solo; resistência do solo a penetração; carbono orgânico.
The presence of organic carbon in soil and plant biomass is beneficial for ecosystem functions and is closely associated with reducing the negative effects of climate change. Soil carbon stocks are controlled by a variety of climatic and biogeochemical factors, being directly influenced by changes in land use and occupation, in particular by the conversion of natural ecosystems into cultivated areas for agriculture and livestock. Thus, this work aimed to study the presence of organic carbon in the soil and the factors that can promote changes in its stock (EstC). To evaluate these factors, this work was divided into three chapters: In chapter 1, a study was carried out based on sample data and results of simulations of carbon stock in the soil, in six different Brazilian biomes (Cerrado, Amazônia, Pantanal, Caatinga , Atlantic Forest and Pampas), as well as verifying the contribution of the factors Biome, Land use systems, Sampled depth and the type of data (sampled or simulated) on the carbon stock of soils. Only 42 papers in more than 200 scientific articles were qualified for this study. To analyze the data, analysis of variance (ANOVA) was carried out following a completely randomized design, in a factorial scheme, whose factors analyzed were land use, soil layer (0.0 - 0.10 and 0.0 – 0.20 m), the biome and the interaction between them, applying the F test at 5% of probability to detect the differences of the factors and the interaction between them, and the Scott-Knott test at 5% was used to detect differences between the means. Complementary to ANOVA, a technique based on principal component analysis (CP) was applied, in order to verify the contribution of the study factors analyzed in the EstC. In the carbon stocks sampled from 0.0 – 0.20 m, there was a significant difference in the Pantanal Biome, with stocks lower than the other biomes in native vegetation as well as in pasture, in the interaction of land use x Pampas Biome. In the simulated data of 0.0 – 0.20 m, significant differences were observed for Atlantic Forest and Pantanal, with values above 43 Mg ha-1, and for land use in pasture and pasture stock in the Pantanal, the lowest values were obtained. Through the CP technique, it was possible to observe that the EstC is correlated with conservation practices, allowing us to infer that agricultural practices influence carbon stock. In Chapter 2, the EstC was verified in different cultivation areas located in the Southeast of Mato Grosso do Sul: degraded pasture, natural cerrado and eucalyptus plantation areas at different stages of development (3, 5, 7, 10 and 14 years) with soil collections carried out in the rows and between the planting rows. The data obtained were analyzed in terms of descriptive statistics and analysis of variance (ANOVA), which followed a randomized block design, in a factorial scheme (5 x 2 + 2) with 4 replications, with five years of eucalyptus plantation (3, 5 , 7, 10 and 14 years), two positions (row and between rows) and two additional treatments (Cerrado and pasture) at four depths (0.0 – 0.10, 0.10 – 0.30, 0.30 – 0 .60 and 0.60 - 1.00 m). The F test was used to detect differences in factors and interactions, Tukey's test to detect differences between the averages of the years of cultivation and Dunnett's test for comparisons between these averages with the averages of the controls and between controls. In the analysis of the EstC, significant differences were found at depth 0.30 – 0.60 m in year 14, between the rows, for eucalyptus (9.99 ± 0.89 Mg ha-1), Cerrado (9.88 ± 0.62 Mg ha-1) and pasture (10.96 ± 0.87 Mg ha-1) and at depth 0.60 – 1.00 m in year 14, in the line, for eucalyptus (11.04 ± 0, 96 Mg ha-1), Cerrado (14.47 ± 0.60 Mg ha-1) and pasture (15.19 ± 1.37 Mg ha-1). Based on the data analysis, it became evident that the preservation of the Cerrado maintains the carbon in the soil and that at the end of the Eucalyptus cycles (7 and 14 years) the values are close to those found in the Cerrado. Finally, in Chapter 3, the measurement of soil penetration resistance (RP) was evaluated by three methodologies using manual spring penetrograph (SC60), benchtop static penetrometer with 60 cm.w.c-water column (PEB60) and benchtop static penetrometer with 100 cm.w.c (PEB100), in 3 cultivation areas (eucalyptus - EUCP, pasture - PAST and conserved cerrado - CERC), in 3 depths (0 - 0.10; 0.10 - 0, 30 and 0.30 - 0.60 m). The data obtained were converted to MPa (for soil penetration resistance), analyzed for descriptive statistics and analysis of variance, and the F test was used to detect differences in factors and interactions, and the Tukey test to compare the means when significant differences were found. PR values above 1.9 MPa were verified with the use of SC-60 in eucalyptus and pasture. Higher RP values were found for pasture at depths of 0.10 - 0.30 m (1.50 MPa), in SC60 in eucalyptus cultivation and pasture (1.90 MPa) and SC60 from a depth of 0. 10 – 0.30 m (1.75 to 2.07 MPa), values considered moderate and not impeding the root development of eucalyptus. SC60 showed the highest RP values (1.16 to 2.07 MPa) regardless of cultivation and depth. There were no significant variations in the RP in relation to the water columns used (60 and 100 cm.w.c.).
The presence of organic carbon in soil and plant biomass is beneficial for ecosystem functions and is closely associated with reducing the negative effects of climate change. Soil carbon stocks are controlled by a variety of climatic and biogeochemical factors, being directly influenced by changes in land use and occupation, in particular by the conversion of natural ecosystems into cultivated areas for agriculture and livestock. Thus, this work aimed to study the presence of organic carbon in the soil and the factors that can promote changes in its stock (EstC). To evaluate these factors, this work was divided into three chapters: In chapter 1, a study was carried out based on sample data and results of simulations of carbon stock in the soil, in six different Brazilian biomes (Cerrado, Amazônia, Pantanal, Caatinga , Atlantic Forest and Pampas), as well as verifying the contribution of the factors Biome, Land use systems, Sampled depth and the type of data (sampled or simulated) on the carbon stock of soils. Only 42 papers in more than 200 scientific articles were qualified for this study. To analyze the data, analysis of variance (ANOVA) was carried out following a completely randomized design, in a factorial scheme, whose factors analyzed were land use, soil layer (0.0 - 0.10 and 0.0 – 0.20 m), the biome and the interaction between them, applying the F test at 5% of probability to detect the differences of the factors and the interaction between them, and the Scott-Knott test at 5% was used to detect differences between the means. Complementary to ANOVA, a technique based on principal component analysis (CP) was applied, in order to verify the contribution of the study factors analyzed in the EstC. In the carbon stocks sampled from 0.0 – 0.20 m, there was a significant difference in the Pantanal Biome, with stocks lower than the other biomes in native vegetation as well as in pasture, in the interaction of land use x Pampas Biome. In the simulated data of 0.0 – 0.20 m, significant differences were observed for Atlantic Forest and Pantanal, with values above 43 Mg ha-1, and for land use in pasture and pasture stock in the Pantanal, the lowest values were obtained. Through the CP technique, it was possible to observe that the EstC is correlated with conservation practices, allowing us to infer that agricultural practices influence carbon stock. In Chapter 2, the EstC was verified in different cultivation areas located in the Southeast of Mato Grosso do Sul: degraded pasture, natural cerrado and eucalyptus plantation areas at different stages of development (3, 5, 7, 10 and 14 years) with soil collections carried out in the rows and between the planting rows. The data obtained were analyzed in terms of descriptive statistics and analysis of variance (ANOVA), which followed a randomized block design, in a factorial scheme (5 x 2 + 2) with 4 replications, with five years of eucalyptus plantation (3, 5 , 7, 10 and 14 years), two positions (row and between rows) and two additional treatments (Cerrado and pasture) at four depths (0.0 – 0.10, 0.10 – 0.30, 0.30 – 0 .60 and 0.60 - 1.00 m). The F test was used to detect differences in factors and interactions, Tukey's test to detect differences between the averages of the years of cultivation and Dunnett's test for comparisons between these averages with the averages of the controls and between controls. In the analysis of the EstC, significant differences were found at depth 0.30 – 0.60 m in year 14, between the rows, for eucalyptus (9.99 ± 0.89 Mg ha-1), Cerrado (9.88 ± 0.62 Mg ha-1) and pasture (10.96 ± 0.87 Mg ha-1) and at depth 0.60 – 1.00 m in year 14, in the line, for eucalyptus (11.04 ± 0, 96 Mg ha-1), Cerrado (14.47 ± 0.60 Mg ha-1) and pasture (15.19 ± 1.37 Mg ha-1). Based on the data analysis, it became evident that the preservation of the Cerrado maintains the carbon in the soil and that at the end of the Eucalyptus cycles (7 and 14 years) the values are close to those found in the Cerrado. Finally, in Chapter 3, the measurement of soil penetration resistance (RP) was evaluated by three methodologies using manual spring penetrograph (SC60), benchtop static penetrometer with 60 cm.w.c-water column (PEB60) and benchtop static penetrometer with 100 cm.w.c (PEB100), in 3 cultivation areas (eucalyptus - EUCP, pasture - PAST and conserved cerrado - CERC), in 3 depths (0 - 0.10; 0.10 - 0, 30 and 0.30 - 0.60 m). The data obtained were converted to MPa (for soil penetration resistance), analyzed for descriptive statistics and analysis of variance, and the F test was used to detect differences in factors and interactions, and the Tukey test to compare the means when significant differences were found. PR values above 1.9 MPa were verified with the use of SC-60 in eucalyptus and pasture. Higher RP values were found for pasture at depths of 0.10 - 0.30 m (1.50 MPa), in SC60 in eucalyptus cultivation and pasture (1.90 MPa) and SC60 from a depth of 0. 10 – 0.30 m (1.75 to 2.07 MPa), values considered moderate and not impeding the root development of eucalyptus. SC60 showed the highest RP values (1.16 to 2.07 MPa) regardless of cultivation and depth. There were no significant variations in the RP in relation to the water columns used (60 and 100 cm.w.c.).
Descrição
Palavras-chave
Uso do solo, Resistência do solo a penetração, Carbono orgânico, Soil depth, Land use, C determination methods