Search

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Vale do Ribeira is one of the largest banana producing regions in Brazil. However, information on soil fertility and nutrient status that could limit fruit production remains scarce. Thus, the present study diagnosed the most limiting nutrient parameters for the Nanica and Prata banana cultivars, in Vale do Ribeira, São Paulo State, based on soil and leaf chemical analyses. The data assessed included samples from commercial plantations in the municipalities of Eldorado, Cajati, Jacupiranga, Pariquera-açú, Registro and Sete Barras, between 2012 and 2020. The results of soil (pH, V, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn) and leaf chemical analyses (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn) were interpreted according to literature values and their maximums, minimums, means, coefficients of variation (CV), and confidence intervals (CI) were calculated at P < 0.05. Parameter classes were assessed according to their frequency distribution. A large part of the samples exhibited pH and V values similar to those recommended for banana plants. Although, average soil nutrient concentrations were considered high, soil K, Mg and S levels did not provide adequate banana plant nutrition, since these nutrients were deficient in the plants. [ABSTRACT FROM AUTHOR]

Este trabalho objetivou diagnosticar a ocorrência de limitações física e química em lavouras manejadas sob sistema plantio direto. O estudo foi conduzido a campo, em 12 talhões agrícolas em Latossolos, Nitossolos e Cambissolos com caráter alumínico. Ao final do ciclo da cultura da soja foi realizada a amostragem do solo no terço superior, no terço médio e no terço inferior da topossequência, totalizando 36 pontos de coleta e cinco métodos de amostragem. Foram analisados a reação do solo (pH-H2O), os teores de fósforo (P) e potássio (K) trocáveis e de matéria orgânica no solo (MO), a densidade do solo (Ds), o volume de poros totais (Pt), de macroporos (Ma) e de microporos (Mi), a taxa estável de infiltração de água no solo (Tei) e o índice de qualidade estrutural do solo (Iqes). A ocorrência de limitação química foi comprovada para o pH-H2O, P e K em 70%, 92% e 75% dos talhões, respectivamente, evidenciada pelos métodos de amostragem de forma estratificada. Os teores de MO foram, em média, de 3,7g dm-3 na camada de 0-20cm. A ocorrência de limitação física foi evidenciada pelos valores de Ds e Ma. O Iqes, com oscilação de 0 a 5, foi, em média, de 3,6. Com base nos critérios estabelecidos constatou-se a presença de limitação química e/ou física em 11 talhões e a amostragem de 0-10cm e 10-20cm como eficaz em identificar a estratificação da fertilidade do solo em SPD.

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A calagem apresenta impactos positivos na qualidade dos solos, como o aumento do pH e na disponibilidade de nutrientes. No estado de Roraima, solos agricultáveis, em grande parte, estão sob domínios do bioma savana e apresentam pH ácido e distrofia, condicionando o uso agrícola a investimentos na correção da fertilidade. Assim, objetivou-se avaliar diferentes métodos de recomendação de calcário e seus efeitos nas características químicas de três tipos de solo, tendo o milho como planta indicadora em um cultivo em vasos. As menores doses consideraram a neutralização da acidez trocável e as maiores a neutralização da acidez trocável e o aumento dos níveis de cálcio e magnésio. No solo mais argiloso, as diferentes doses de calcário não afetaram a produção inicial de biomassa seca; dessa forma, um método que garanta o fornecimento de cálcio e magnésio para a cultura, além de neutralizar as formas tóxicas de alumínio, é o mais adequado. Nos solos mais arenosos e com baixo poder tampão, predominantes na savana, as maiores doses de calcário reduziram a produção de biomassa. Nesses solos, o método baseado na neutralização do alumínio trocável foi eficiente em elevar o pH e reduzir o Al trocável, mas não garantiu teores de cálcio e magnésio adequados para a necessidade da cultura. Os resultados obtidos evidenciam a importância de uma abordagem individualizada na determinação da necessidade de calagem para os solos de Roraima.

O objetivo da pesquisa é analisar doses crescentes de adubação fosfatada em dois diferentes híbridos de milho cultivados em solo arenoso. O delineamento experimental foi de blocos casualizados, em esquema fatorial 2 x 5, sendo dois híbridos de milho (Brevant 688 e Agroceres 1051) e cinco doses de fósforo (0; 50; 100; 150 e 200 kg ha-1 de P2O5), replicadas quatro vezes. A fonte de fósforo utilizada foi o monofosfato de amônio. O solo utilizado foi coletado de um Neossolo Quartzarênico com 903 g kg-1 de areia. Aos 45 dias após o plantio dos híbridos foram mensuradas as características estruturais como altura de plantas e o diâmetro de colmo. A biomassa vegetal foi pesada e seca para a obtenção dos dados que foram submetidos à análise de variância e estudo de regressão. As plantas híbridas de milho diferem em suas respostas à aplicação de fósforo em solo de textura arenosa, indicando a necessidade de diferentes recomendações de adubação fosfatada no mesmo solo para diferentes híbridos, sendo que para o genótipo Brevant 688 ocorreram as maiores produções indicando maior potencial para a utilização desse material para as condições de textura extremas impostas neste estudo.

O objetivo deste estudo foi caracterizar os solos de ecossistemas de veredas e de seus respectivos cerrados de entorno, em diferentes estágios de degradação. Foram selecionadas três veredas (Água Doce, Capivara e Buriti Grosso) e seus respectivos cerrados do entorno. As amostragens de solo foram realizadas nas camadas de 0–10, 10-20, 20-30, 30-40, 40-50, 50-75 e 75-100 cm de profundidade, para avaliação dos atributos químicos, granulometria, densidade aparente e estoque de nutrientes do solo. Os dados foram submetidos à análise de variância e comparados pelo teste Tukey (p

Brazil stands out in the international scenario as the largest producer of sugarcane, processing billions of tons. Thus, this activity generates residues, such as ashes from bagasse burning and straw from sugarcane cleaning and from the production of sugar, alcohol and thermal energy. Therefore, the objective was to evaluate the initial performance and chlorophyll content of pigeon pea and the chemical attributes of the soil after application of ash doses. The experiment was conducted in 2021, in a greenhouse located in southwestern Goiás, Brazil. The design used was completely randomized, composed of five ash doses: 10, 20, 30, 40 and 50 Mg ha-1 and a control treatment, with four replicates, totaling 24 experimental units. The use of only ash as a fertilizer source causes linear increases in the initial growth of pigeon pea and in the contents of total chlorophyll and chlorophyll b, reaching the maximum increments with the estimated ash doses of 35.9 and 38.9 Mg ha-1. Applications of high ash doses promoted improvements in soil fertility, with increase in pH, P, K and base saturation as well as reduction in aluminum content and aluminum saturation. Calcium and magnesium contents reached the maximum increments with the estimated ash doses of 39.5 and 66.7 Mg ha-1, respectively.

The aim of this study was to characterize the soils of veredas (Brazilian palm swamps) ecosystems and their surrounding savannas, in different stages of degradation. Three veredas (Água Doce, Capivara and Buriti Grosso) and their respective surrounding cerrados (savannas) were selected. Soil sampling was performed in the layers 0-10, 10-20, 20-30, 30-40, 40-50, 50-75 and 75-100 cm to assess chemical attributes, granulometry, bulk density and stocks of soil nutrients. The data were subjected to analysis of variance and compared by Tukey test (p < 0.05). The soils in both environments were classified as sandy presenting high apparent density (1.40 to 1.65 g cm-3). The pH in the preserved vereda was higher in relation to the anthropized areas. In both areas the pH was acidic, with very low sum of bases, Al and potential cation exchange capacity (CTC). Nutrient stocks were similar between areas and higher in savanna environments. Potassium showed the greatest variation, with higher values in areas with degradation. We concluded that anthropic interventions in the studied environments influenced soil attributes. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Os resíduos orgânicos como os estercos estão sendo cada vez mais utilizados para a fertilização do solo, seja no campo ou durante a produção de mudas. Essa utilização deriva da sua capacidade de melhorar tanto as características químicas quanto às físicas do solo e por consequência, as condições para o crescimento da planta. No entanto, as modificações nas características químicas do solo podem ser favoráveis ou não, dependendo da dose e do resíduo aplicado. Diante disso, desenvolveu-se estudo com o objetivo de avaliar as diferentes doses de estercos bovino, equino e de aves nas modificações das características químicas de um latossolo. Para isso, foram realizados três experimentos utilizando estercos de diferentes origens, em delineamento inteiramente casualizado, com os seguintes tratamentos: 0 t ha-1 de esterco; 10 t ha-1 de esterco; 20 t ha-1 de esterco; 30 t ha-1 de esterco; 40 t ha-1 de esterco. Cada dose (tratamento) foi testada com a adição de esterco bovino, esterco equino e esterco de aves, em sacolas plásticas preenchidas com Latossolo Vermelho distrófico, com seis repetições. Ao final de 90 dias, foram avaliadas as características químicas do solo, verificando-se que, a adição de esterco influenciou positivamente nessas características. O esterco de aves, na dose de 30 t ha-1 , foi o que apresentou os maiores efeitos redutores da acidez do solo, em função dos teores de bases e do aumento em V%, que diminuiu os teores de H, Al e m%, aumentando o pH do solo.

Knowledge on the spatial variability of chemical and physical attributes and magnetic susceptibility of the soil is important for precision agriculture, especially in Cerrado areas, which have limitations due to low natural fertility and acidity. The objective was to analyze the spatial variability of chemical attributes, penetration resistance, and magnetic susceptibility in a Cerrado area. The experiment was carried out in the municipality of Corrente-PI. A sampling grid was defined, with points spaced every 20 m, totaling 50 points, and soil was collected at a depth of 0.00-0.20 m. pH in water, phosphorus (P), organic matter (OM), potassium (K+), calcium (Ca2+), magnesium (Mg2+), H + Al (potential acidity), and aluminum (Al3+), sand, silt, clay (Texture), penetration resistance (PR) and magnetic susceptibility (MS) were analyzed and the sum of bases (SB), cation exchange capacity (CEC) and percentage of base saturation (V%) were calculated. The values of chemical attributes had positive and negative relationships with pH. Penetration resistance showed that the area is under adequate management conditions and the magnetic susceptibility was considered low, reflecting the parent material, sandy rock. The Cerrado area has more than 50% of its extension with medium to high acidity and low fertility levels. The Cerrado area, in all aspects, has adequate values of soil penetration resistance and low magnetic susceptibility, probably resulting from the sandy soil, proven by the textural analysis. [ABSTRACT FROM AUTHOR]

This research evaluated the effect of liming (with and without) and biochar (with and without) on sorghum cv. BRS Ponta Negra growth and Arenosol chemical properties in the Semiarid environment. The experimental design was in randomized blocks, with treatments in a 2x2 factorial scheme, corresponding to the application or not of lime (0 and 2.5 t ha-1) and biochar (0 and 12.5 t ha-1). Biochar was produced from cashew branches. The experiment was conducted in 16 m² plots where the forage sorghum cultivar BRS Ponta Negra was cultivated. The soil chemical characteristics, the production attributes, and the structural characteristics of the sorghum cultivar studied were evaluated. There was no interaction between factors. The use of biochar increased the pH and Ca and P contents in the soil and contributed to increasing the panicle mass (2.51 t ha-1 of DM). Lime application affected the soil Ca content as the dose of 2.5 t ha-1 resulted in higher values of culm diameter (15.25 mm), panicle mass, and culm mass (2.63 and 7.50 t ha-1 of DM, respectively). Therefore, these results allowed to outline strategies for the use of limestone and biochar for forage production in semiarid environments in sandy soils. Because, these materials improve some chemical attributes of the soil and the production of forage sorghum. It is noteworthy that edophoclimatic conditions can change the response patterns observed in this research. Therefore, research in other regions is essential. [ABSTRACT FROM AUTHOR]

The combined application of chemical fertilizer and organic fertilizer is an effective way to improve soil fertility, crop yield and quality. In this study, a field experiment was conducted to evaluate the yield, quality and fertilizer use efficiency of cabbage (Brassica oleracea var. capitata L.) grown under different ratios of organic fertilizer replacing chemical fertilizer at a rate of 225 kg N ha-l in 2019 and 2020. The fertilizer treatments included N0 (non nitrogen fertilizer), CK (only compound fertilizer was applied, N:P:K=15.0 %:6.5 %:12.4 %), T1, T2 and T3 (organic fertilizer replaced 15 %, 30 % and 45 % chemical fertilizer, respectively), and T4 (total nutrient input was reduced by 10 % under T2). Results showed that T2 had the highest marketable yield and fertilizer use efficiency, as well as the best quality. The marketable yield, vitamin C content, soluble sugar content, REN (apparent uptake efficiency of fertilizer N) and AEN (agronomic N use efficiency) of T2 increased by 32.2 %, 14,9 %, 5.5 %, 97. % and 55.6 %, respectively, in contrast, the crude fibers decreased by 34.0 %, compared with CK in the two years. In addition, T4 guaranteed the yield and moderately improved the quality of cabbage, compared with CK. Therefore, we can alternatively apply fertilization according to the purpose of capturing the highest yield or properly declining fertilizer to sustain soil texture and productivity. [ABSTRACT FROM AUTHOR]

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hops (Humulus lupulus) is a plant with potential for cultivation in the Center-South region of Paraná, Brazil. However, there are no official Brazilian recommendations for production of seedlings or fertilization and liming. The aims of this work were to evaluate the production of hop seedlings and verify the development of hop plants grown in soil with different pH values and K2O rates, in the Center-South region of Paraná, Brazil. Three experiments were carried out: i) cuttings of a plant were dipped in a 1% indole-3-butyric acid (IBA) solution and placed in different substrates - the sprouting and survival of the hop seedlings was verified; ii) hop seedlings were transplanted to a soil with different pH values (4,5; 5,5; 6,0 and 6,5) - the development and nutrients uptake by the plants was evaluated; iii) hop seedlings were transplanted to a soil with different K2O rates added - the development and K uptake by the plants was assessed. The substrate for seedling production did not influence the sprouting of hop cuttings, but the presence of IBA reduced sprouting and growth up to 41 days. The pH 5,5 value in the soil provided the best hop development by increasing the production of fresh and dry biomass in comparison with pH 4,5. Hop plants in soil with pH 6,0 and 6,5 showed lower chlorophyll content, but maintained the same nutrient uptake. The production of dry biomass of hop plants and the K content of the roots increased with the K2O rates added to the soil, However, K was not transferred to the aerial part of the plants in the initial phase of development. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Floodplains were the first deforested areas for agriculture use all over the world. In Brazil these areas can be restored by the growth of guanandi Calophyllum brasiliense, a slow-growing native forest species adapted to flooding. The aims of this study were to: (i) evaluate the taro, Colocasia esculenta, management under two agroforestry systems (AFS) (Simple and Biodiverse) in succession to a reforestation with guanandi, (ii) evaluate the contribution of macronutrients from the green manure Flemingia macrophylla and Sesbania virgata, both managed using pruning for green manure in the respective AFSs, and (iii) the effects on soil nutrients levels compared to monoculture of guanandi (control). The randomized block was designed with eight replication and 216.0 m² plots with four rows of six guanandi trees in each line. In the simple AFS (SAFS), the taro was intercropped with Flemingia and in the biodiverse AFS (BAFS), Sesbania, banana shrub (Musa sp.), edible palm (Euterpe edulis) and fourteen species of native trees were included. Production was evaluated in seasons with high rainfall and water scarcity. With floods the taro has produced around 15 Mg ha-1 of marketable corms in the SAFS and 9 Mg ha-1 in the BAFS, but the drought has made commercial production unfeasible, with no differences between cormels and corms planting. However, enough rhizomes were harvested for a new planting. Flemingia has accumulated 17 Mg ha-1 of fresh matter and Sesbania contributed with 2 Mg ha-1. Soil pH and macronutrient content, especially K, were significantly higher in AFSs areas compared to guanandi monoculture. [ABSTRACT FROM AUTHOR]

The intensive use of land has accelerated the loss of soil quality, a process that can be avoided by adopting conservationist production systems, such as the Integrated Crop-Livestock-Forest (CLFI system). It is noteworthy that in the Southwest of the State of Maranhão a substantial portion of soils in rural properties are degraded and in distinct stages of erosion, since they have been exploited for decades with non-properly managed pastures. Therefore, the objective of this work was to emphasize the importance of physical and chemical changes in the soil of pastures under crop-livestock-forest integration in general and in the Amazon region of state of Maranhão, Brazil. Therefore, a literature review was conducted through a search for studies in the Google Scholar database, which encompasses multiple other databases, such as Scielo, Elsevier, Scopus, Capes, and others. In face of the conditions of degradation in pastures throughout the state of Maranhão and the broad distribution of native forests such as Babassu forests, the use of technology from CLFI systems could allow for their recovery and sustainable status by means of economically and ecologically feasible productivity. Research on this field is therefore necessary to highlight short-and long-term efficiencies regarding carbon sequestration and quality of organic matter on the soil. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A modelagem matemática ao semivariograma, moderado pela geoestatística, é uma ferramenta capaz de contribuir para pesquisas sustentáveis. A necessidade de estudos de solo na provincia de El Oro, Equador, possibilitou relizar esse estudo e gerar informações por meio da análise de variabilidade e estabelecimento da estrutura de dependência espacial e correlação linear de alguns atributos do solo, a fim de auxiliar no planejamento de atividades agrícolas em seis cidades. Em todas elas foram realizadas análise descritiva inicial, geoestatística e matriz de correlação linear simples com base em uma malha com 368 pontos amostrais. Apenas o pH e areia apresentaram coeficiente de variação alta (22,02% e 25,42%), todos os outros atributos apresentaram variação muito alta. A maioria dos semivariogramas foram ajustados ao modelo esférico; o maior alcance foi indicado pelo magnésio (41.500 m) e o menor pelo cobre (7.740 m). O número de pares no primeiro LAG mostrou influência no alcance e no ADE para o teor de Zinco. O par Mg versus soma de bases foi a maior correlação linear dentre todos os atributos analisados. O pH se destacou como intermediador e influenciador de outros atributos do solo.

Cultivos antecedentes podem modificar os atributos químicos do solo e a produtividade das culturas. Objetivou-se avaliar os atributos químicos do solo e os componenetes de produtividade da soja após cultivos de outono-inverno. O experimento foi conduzido na área experimental da Embrapa Agropecuária Oeste em Dourados-MS, em Latossolo Vermelho distroférrico de textura argilosa. O delineamento experimental foi em blocos casualizados com parcelas subdivididas, com quatro repetições. Para as avaliações químicas do solo foram consideradas nas parcelas os cultivos de outono-inverno (Brachiaria ruziziensis, milho safrinha, consórcio de milho com B. ruziziensis e feijão-caupi) e as sub-parcelas as profundidades do solo (0-10; 10-20; 20-30 e 30-40 cm). Já para os componentes de produtividade da soja, considerou-se nas parcelas os cultivos de outono-inverno e as subparcelas as cultivares de soja (BRS 284 e BRS 360 RR). O tipo de cultivo interferiu nos atributos químicos do solo que, de modo geral apresentou maiores valores de nutrientes em profundidades superficiais. O feijão-caupi, milho safrinha e B. ruziziensis proporcionaram condições para a maior produtividade da soja. A BRS 284 apresentou maior número de grãos por planta, no entanto a BRS 360 RR demonstrou ser mais produtiva.

This study aimed to evaluate changes in soil chemical attributes and nutrition of Anadenanthera colubrina and a Eucalyptus clone under fertilization using reservoir sediment (RS), fish farming sediment (FFS) and biochar (BC) in the semi-arid region of Brazil. The Eucalyptus clone and A. colubrina leaves and soil were sampled after applying treatments. Leaves were collected for nutritional analysis and soil for mineral and fertility analyses. The K+ and P concentration in the soil were influenced by the natural fertilizers, and the biochar increased the C content. The A. colubrina planting reduced the soil K+ and P levels, and the Eucalyptus clone cultivation reduced the Mg2+ content. The FFS was responsible for increasing P availability in both A. colubrina and the Eucalyptus clone, being a good option for use in soils which are naturally poor in P. A. colubrina presented the highest N, P, K and Ca levels, suggesting high demand of this species for these nutrients. The Eucalyptus clone was more demanding for Mg, suggesting that its cultivation should be done in soils rich in Mg2+. The use of RS and FFS is important to increase the growth of forest species in semi-arid regions, and this management is recommended in the deforestation policies of these regions. [ABSTRACT FROM AUTHOR]

Com o objetivo de avaliar sistemas de rotação de culturas para hortaliças, conduziu-se um experimento na Epagri/Estação Experimental de Urussanga, no período de agosto de 1994 a junho de 2000. Sete hortaliças e as culturas de aveia e mucuna foram arranjadas em sistemas com um, dois e três anos de rotação. O efeito da rotação foi significativo na produtividade e na qualidade da batata-doce, da cenoura, da beterraba e do repolho. O cultivo da aveia e da mucuna reduziu as capinas e facilitou o cultivo mínimo do tomateiro. A rotação de culturas reduziu a incidência de doenças na cultura da cenoura. Os níveis de fósforo no solo elevaram-se, acentuadamente, a partir do terceiro ano de cultivo, em todos os sistemas de rotação. A matéria orgânica do solo aumentou gradativamente, em todos os sistemas.

Applying biofertilizers made from wastes from tropical forest agroextrativism to improve the fertility of acidic and nutrient-poor soils is a viable strategy for sustainable development of family farming in Brazil's North region. In this respect, the objective of this study was to evaluate the effect of applying biofertilizers based on locally available organic wastes on the fertility of a Dystrophic Yellow Latosol. The experiment was carried out in the Fazendinha experimental field of the Embrapa Amapá research unit, located in the municipality of Macapá, Amapá. We used a randomized block design with split-plots in space, with five replications. The plots consisted of seven fertilizations, with a control treatment (without fertilization) and six biofertilizers based on fresh cattle manure, shoot of Cecropia sp., leaves of Gliricidia sepium or Inga edulis and leaf sheath of Euterpe oleracea or pseudostem of Musa sp.; and the subplots were the two soil depths analyzed (0 to 2.5 and 2.5 to 5 cm). The biofertilizers promoted the correction of the soil acidity, increased the contents of organic matter, P, K+, Ca2+, Mg2+, and raised the sum of bases, cation exchange capacity and base saturation percentage, especially in the surface layer. It was observed a reduction in the chemical limitations on the Dystrophic Yellow Latosol by applying biofertilizers based on locally available organic wastes and the increase in organic matter in the soil positively correlated with the increase in the levels of the beneficial chemical attributes of the Dystrophic Yellow Latosol. [ABSTRACT FROM AUTHOR]

Copyright of Tecno-Lógica is the property of Tecno-Logica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Para a determinação da fertilidade do solo, uma característica das amostras simples comumente desprezada é o seu volume, que apresenta relação com o número de amostras coletadas para formar uma amostra composta representativa. O objetivo deste trabalho foi estabelecer a influência do volume das amostras simples na estimativa da variabilidade de características químicas do solo e estimar os desvios em torno da média tolerados na coleta de 20 amostras simples com diferentes equipamentos em um Latossolo Vermelho-Amarelo argiloso cultivado com café arábica. Foram coletados cinco grupos de 30 amostras simples de solo, com os respectivos volumes: 80, 320, 720, 1.280 e 2.000 cm3, na camada de 0-20 cm, totalizando 150 amostras simples. Nessas amostras foi determinado pH, P, K, Ca2+, Mg2+ e Al3+. Foram selecionados modelos que explicassem a variação dos teores em função do volume das amostras de solo. Foram ainda calculados os desvios em torno da média tolerados utilizando três equipamentos: trado, sonda e enxadão. O aumento no volume de solo coletado reduziu a variabilidade das características e consequentemente o número de amostras simples necessário para formar uma amostra composta. O enxadão mostrou-se o equipamento de coleta mais eficiente, uma vez que proporcionaria maior representatividade da amostra composta formada.

Visando avaliar o efeito do esterco líquido de suínos e do adubo nitrogenado na produção de milho em sistema plantio direto, foram conduzidos dois experimentos em Chapecó e Guatambu, SC, sobre um Latossolo Vermelho distroférrico típico, no período de 2000 a 2004. O delineamento experimental foi em blocos casualizados com três repetições e tratamentos dispostos em parcelas subdivididas. Nas parcelas foram aplicados zero, 40 e 115m3/ha de esterco na superfície e 40m3/ha no sulco de semeadura. Nas subparcelas foram aplicados zero, 60 e 120kg/ha de N, sendo um terço na semeadura e dois terços 45 dias após. Em Guatambu, a resposta do milho à adubação nitrogenada mineral e ao esterco foi significativa nos anos com incrementos lineares para N mineral, na ausência de esterco, e com efeito quadrático para esterco, na ausência de N mineral. O rendimento máximo foi obtido com aplicação de 85m3/ha de esterco. Em Chapecó, em área adubada com esterco por vários anos, a resposta do milho à adubação nitrogenada e esterco foi menor. Não foram observadas diferenças em produção de grãos entre os modos de aplicação do esterco.

The aim of this study was to evaluate the chemical quality of a Typic Hapludult soil under secondary forest (capoeira), pasture and three leguminous tree species: Acacia auriculiformis, Mimosa caesalpiniaefolia and Inga edulis, in Conceição de Macabú County, Rio de Janeiro State, Brazil, implemented in December 1998. Soil samples from the 0-0.10 and 0.10-0.20 m layers were collected and analyzed in July/2015. The C content in the 0.10 m layer was higher in capoeira and lower in the pasture. The CECef and CECpH=7 values and the N, P, Ca, Mg and K levels were lower in pasture, higher in Acacia auriculiformis or capoeira, and intermediate in Inga edulis and Mimosa caesalpiniaefolia. The chemical variables regarding the vegetation cover generally had the lowest values in the pasture, the highest in the Acacia auriculiformis or capoeira, and intermediate values in Inga edulis and Mimosa caesalpiniaefolia. It was concluded that revegetation leads to changes in the superficial layer of the soil which make its attributes closer to those of capoeira and further away from those of pasture, indicating an increase in quality to support the functioning of a forest ecosystem, despite the worsening of some Agronomic quality indicators. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Ambiente e Água is the property of Revista Ambiente e Agua and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Estudos que avaliam a resposta dos cultivos agrícolas às modificações do solo com a gessagem são relativamente abundantes, mas concentrados majoritariamente em terras altas. Este trabalho objetivou avaliar a acidez e a disponibilidade de fósforo (P) e potássio (K) do solo e a produtividade do arroz irrigado e da soja, cultivados em terras baixas, com aplicação de doses de gesso agrícola. Os experimentos foram conduzidos em um Planossolo Háplico (Triunfo/Rio Grande do Sul). Os tratamentos consistiram em seis doses de gesso agrícola (0,00; 0,25; 0,50; 1,00; 2,00; e 4,00 t ha-1) e o delineamento experimental foi o de blocos casualizados. O solo foi coletado após a colheita das lavouras, nas camadas de 0–5, 5–10, 10–20 e 20–40 cm. O pH em água, a acidez potencial (H+Al) e o P disponível (Mehlich 1) não foram alterados com a aplicação de gesso agrícola. Após o cultivo de arroz irrigado e na camada de 0–5 cm, houve aumento do teor de K disponível (Mehlich 1) para doses até 1,00 t ha-1 e diminuição do teor para doses maiores (2,00 e 4,00 t ha-1). Após o cultivo de soja, o teor de K disponível não foi alterado com a gessagem. A aplicação de gesso agrícola não influenciou a produtividade do arroz irrigado e da soja na safra avaliada, onde não houve déficit hídrico.

Com a aplicação de técnicas agroflorestais, a produtividade de estabelecimentos agropecuários e de plantações florestais de diversas dimensões podem se estabilizar, evitando a degradação do solo ou perda de produtividade ao longo dos anos. Já os fatores edafoclimáticos, como luminosidade, temperatura e umidade no solo, também influenciam a manutenção da produção e os sistemas agroflorestais (SAFs) por constituírem uma importante estratégia para garantir maior estabilidade dessas condições. Assim, objetivou-se avaliar propriedades físicas e químicas do solo em SAFs considerando a sazonalidade (período seco e chuvoso). O estudo foi realizado em três diferentes sistemas agroflorestais, todos localizados no município de Belterra (PA), por meio da avaliação química, física, da luminosidade e temperatura do solo em relação a variáveis climáticas. Os nutrientes apresentaram, na maior parte do ano, baixos teores no solo (0-20 cm de profundidade), e, em todos os SAFs, a ciclagem de nutrientes ainda não provê a quantidade necessária de nutrientes para a manutenção das necessidades de produção das culturas. O SAF 1 apresentou as maiores porcentagens de argila (24,0%) e o SAF 3, a maior quantidade de areia (89,5%). Os valores de densidade do solo determinados foram abaixo dos limites críticos ao desenvolvimento da vegetação. Observou-se maior umidade do solo em sistemas com teores mais elevados de argila. As condições edáficas foram fortemente influenciadas pelo manejo dos SAFs, pela composição e arranjo das espécies inseridas.

O potássio é considerado o nutriente mais extraído pela mandioca. Dessa forma, sua baixa disponibilidade no solo afeta o crescimento da planta, com reflexos na expansão da área de cultivo e produtividade da lavoura em áreas deficientes deste nutriente. Objetivou-se com o presente trabalho estabelecer curvas de crescimento de plantas de mandioca, cultivar Aciolina, submetidas a cinco doses de potássio em ambiente de savana do estado de Roraima. Utilizou-se o delineamento experimental em blocos casualizados, com quatro repetições, em esquema de parcelas subdivididas. Cinco doses de potássio (0, 30, 60, 120 e 240 kg ha-1 de K2O) foram aleatorizadas nas parcelas e épocas de avaliação (150, 210, 270 e 360 dias após o plantio – DAP) nas subparcelas. As variáveis analisadas: diâmetro do caule, altura da primeira ramificação, altura da planta e características da folha. O crescimento em altura da cv. Aciolina se deu em todos os níveis de adubação com potássio, indicando que o baixo teor de K restringe o crescimento da planta em altura. Os componentes de crescimento da planta de mandioca, diâmetro do caule, altura da primeira ramificação e altura da planta foram afetados positivamente por doses crescentes de potássio até 240 kg ha-1. A largura da folha, o número de lóbulos e a relação entre comprimento do lóbulo central pela largura do lóbulo central não são afetados pelas doses de potássio.

O presente trabalho objetivou organizar e analisar um banco de dados geoespacial de informações pedológicas e aplicar técnicas de geoestatística para avaliar a dependência espacial de atributos físicos e químicos do solo. Para tanto, buscou-se confeccionar uma base de dados com 473 pontos amostrais pertencentes a uma grade não regular, coletados em duas profundidades, 0,00 a 0,25m, e 0,25 a 0,50m, devidamente georeferenciados. Estas amostras foram coletadas sob a cultura da cana-de-açúcar em diferentes idades de corte, sendo a amostragem realizada no meio da entrelinha da cultura, com o auxílio de um trado holandês e posteriormente submetido às determinações analíticas químicas e físicas em laboratório. Baseado nesses resultados, determinou-se, ainda, o potencial de produção de cana de açúcar para a região de estudo. Em seguida realizou-se a análise descritiva dos dados, estabelecendo-se correlações lineares, simples e múltiplas, entre os atributos. Foram modelados semivariogramas, obtendo-se as respectivas krigagens e validações cruzadas. Também foram estabelecidas as cokrigagens de interesse. Os atributos Ca, Mg, K e MO apresentaram forte dependência espacial na camada superficial. A variável ambiente relacionou-se negativamente com todos os atributos e camadas, exceto argila, areia fina e alumínio.

Trabalhos de pesquisa no Brasil e em outros países, com a utilização de silicato de cálcio, vem mostrando resultados promissores na cultura da cana- de- açúcar. Este trabalho objetivou avaliar o efeito residual da aplicação do silicato de cálcio como material corretivo de acidez do solo, nos atributos químicos do solo e na produtividade da primeira soqueira de cana-de-açúcar. O trabalho foi desenvolvido, em condições de campo, na Fazenda Escola da Anhanguera de Dourados-MS, com a variedade SB803250. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições. Os tratamentos foram constituídos de doses distintas de silicato de cálcio (0, 700, 1400, 2800, 5600 kg ha-1). No solo, a amostragem foi realizada aos 24 meses após a aplicação do silicato de cálcio, nas camadas de 0-0,2- e 0,20-0,40 m de profundidade, determinando os atributos químicos para fins de fertilidade do solo e a produtividade da cana-soca. O silicato de cálcio promoveu efeito residual benéfico nos atributos de acidez do solo após 24 meses da aplicação. A aplicação do silicato de cálcio, em pré-plantio, promoveu efeito residual positivo na produtividade da soqueira da cana-de-açúcar.

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

: Silicon (Si) plays an important role in sugarcane, but there is a gap of information regarding the potential of diatomite as a Si fertilizer to this crop. Here, we assessed the effects of five rates (equivalents to 75; 150; 225; 300 and 375 kg ha-1 Si) of a diatomite-based fertilizer on the biomass yield and concentration of nutrients and Si in sugarcane plants grown on a sandy soil. The efficiency of the extractants acetic acid and calcium chloride in predicting Si uptake was also assessed. Results showed that diatomite was efficient in supplying available Si in the soil and increased Si concentration in the plant. The addition of diatomite significantly increased the available contents of P, K, Mn, Cu, and the cationic exchangeable capacity of the soil. The concentrations of N, P, Mn, Cu, and Zn in shoots were elevated, suggesting that the fertilizer can play a role in the efficient use of nutrients by sugarcane. The extractant 0.01 mol L-1 CaCl2 was better correlated with Si concentration in plants than 0.5 mol L-1 acetic acid. Therefore, CaCl2 is the recommended extractant to estimate Si availability because of its higher efficiency and lower cost. [ABSTRACT FROM AUTHOR]

The non-native grass Megathyrsus maximus (Guinea grass) have been reported as a threat for woody species regeneration in the first years of tropical forest restoration, in some cases persisting for several years. The objective of this work was to evaluate forest restoration sites, correlating M. maximus and other ruderal species density and dry biomass with reforestation age, canopy openness, species richness, abundance of planted trees, and soil fertility. Seventeen sites reforested with native species were selected, with planting ages between 40 and 110 months, at the Capivara Reservoir, Southern Brazil. In each site, ten 10-m2 plots each with four 1-m2 subplots were installed, where soil fertility, plant abundance (M. maximus, native and ruderal species) and dry biomass (M. maximus and ruderal species only) were recorded. All sites showed high fertility soils, and the canopy openness (21.5 a 38.5 %) decreased with time. Ruderal species abundance were positively correlated with canopy openness and negatively correlated with planting age. Both dry biomass (ranging from 0 to 182 g/m²) and clump density (ranging from 0 to 2 clumps per m²) of M. maximus were not correlated with reforestation age or canopy cover. Moreover, with the exception of soil magnesium concentration, none of soil fertility variables could explain M. maximus abundance or biomass, indicating a high phenotypic plasticity in this non-native grass species. It was remarkable that almost 10 years after planting, the reforested sites did not successfully suppress Megathyrsus maximus even though canopy openness decreased. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of rock powder as a source of nutrients to plants can be an alternative or complement to mineral soluble and organic sources. Thus, the aim of this study was to evaluate the potential of different rock powder doses, associated or not with livestock manure, as a source of nutrients for bean and its effect on soil chemical attributes. The treatments consisted of the application of 0, 3, 6, 9 and 12 Mg ha-1 of rock powder, associated or not with livestock manure (17 Mg ha-1), applied on the soil surface, without incorporation. The experiment was carried out in completely randomized blocks, with three replicates, and in a factorial arrangement (5x2). The grain yield of bean, height plants and number of plants m-2 were not influenced by the treatments. On the other hand, the application of 3 Mg ha-1 of rock powder associated with livestock manure resulted in a higher number of grains per pod, and the increase in the rock powder doses affected the number of pods per plant. In the soil, only the manure application, regardless of the rock powder, resulted in effects: reduced potential acidity and potential cation exchange capacity, and increased phosphorus content and base saturation. Thus, rock powder, associated or not with livestock manure, is not effective in improving bean yield and soil chemical attributes after approximately three months of application, and the use of livestock manure, regardless of the rock powder doses, improves some chemical attributes in the soil. [ABSTRACT FROM AUTHOR]

The objective of this study was to generate information through the analysis of variability and given structure of spatial dependence as well as the linear correlation of physical and chemical attributes of the soil, in order to assist in the planning of agricultural activities in six cities in the province of El Oro, Ecuador. The soil sample collections were carried out every two kilometers in the form of a grid with small changes in the field with a Dutch-type auger and GPS for georeferencing, with a depth of 0-0.20 m, thus totaling 368 points in the sample grid. Chemical and physical attributes of six municipalities in the province of El Oro were evaluated: Huaquillas, Machala, Chilla, Atahualpa, Portovelo and Las Lajas. The sampling was carried out in each city, but not between them. Distances between cities were 20,000 km to 180,000 km. Each soil attribute was subjected to an initial descriptive analysis, geostatistics and simple linear correlation matrix. Only pH and sand showed a high variation coefficient (22.02% and 25.42%) and all other attributes showed very high variation. Most of the semivariograms were adjusted to the spherical model. The longest range was indicated by magnesium (41,500 m) and the shortest by copper (7,740 m). The Mg pair versus sum of bases was the highest linear correlation among all the analyzed attributes. The pH stood out with a greater linear correlation between the other chemical attributes of the soil and its specific management zones. In view of the great taxonomic variation of the soil, climatic types, cultures used and management adopted, a specific analysis in each city is recommended for better agricultural recommendations. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present work had as objectives to evaluate nutrient levels over four consecutive years of cultivation, in a consortium of pasture legumes system with coastcross and grass, and the grass coastcross in exclusive cultivation. The experimental design used was randomized blocks with composted plots and not composted, in time. The treatments tested were the Arachis pintoi CV. Amarillo consorted with coastcross grass, Arachis pintoi CV. Belmonte grass intercropping coastcross, Stylosanthes guianesis CV. Mineirão grass intercropping coastcross, Stylosanthes guianesis cv. Mineirão consorted with coastcross grass, and the grass coastcross in monoculture. The samplings were carried out in 0-20 depth cm in 2 years. We evaluated the levels of phosphorus, potassium and soil organic matter. And the soil samples for evaluation of physical parameters, where the ring was used at the end of the collection period of collecting samples of plants, 36 months after implementation of the experiment. The data were subjected to analysis of variance and averages were compared by Tukey test at 5% probability level. There were no significant differences between the levels of phosphorus in the evaluated period (2 years). Potassium levels showed significant difference only for those portions that have not received fertilization in the evaluated period. In relation to these organic matter levels were different on the plots fertilized and not composted in the evaluated period. Not been verified effects on soil physical characteristics. [ABSTRACT FROM AUTHOR]