Gesso e composto orgânico no preparo de solo, enxofre em cobertura, na nutrição, produção e características físico-químicas da couve-de-folha
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2018-02-19
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Universidade Estadual Paulista (Unesp)
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A couve-de-folha se destaca por ser uma hortaliça muito cultivada e consumida no estado de São Paulo, no Brasil e em todo mundo. Considerando que as brássicas são exigentes em enxofre, e devido à falta de dados e pesquisas realizadas com este nutriente na cultura da couve-de-folha, objetivou-se com este trabalho avaliar a necessidade do enxofre associado ao nitrogênio em cobertura na nutrição, produção e características físico-químicas da couve-de-folha cultivada com gesso e composto orgânico no plantio. O trabalho foi conduzido na Fazenda Experimental São Manuel, pertencente à Faculdade de Ciências Agronômicas (FCA) da Universidade Estadual Paulista (UNESP), Campus de Botucatu, localizada no município de São Manuel-SP. Foi realizado um experimento onde foram estudados doze tratamentos, em esquema de parcelas subdivididas, sendo três tipos de preparo de solo as parcelas, e quatro doses de enxofre em cobertura as subparcelas. Foram adotados três tipos de preparo de solo: composto orgânico (30 t ha-1); gesso agrícola (1,2 t ha-1) e composto orgânico (30 t ha-1) mais gesso agrícola (1,2 t ha-1), incorporados em pré-plantio. No capítulo 1 foram realizadas sete aplicações de enxofre em cobertura, resultando nas doses totais de 0; 93,31; 186,69 e 280 kg ha-1 de S, correspondendo a 0; 465,5; 931 e 1400 kg ha-1 de sulfato de amônio. Foram avaliadas as seguintes características: diâmetro do caule, comprimento total e largura das folhas comerciais, número e massa fresca de folhas comerciais por planta, massa seca e produtividade (t ha-1). Para avaliação das características físico-químicas das folhas realizadas no capítulo 2 foram utilizadas folhas da 6ª colheita, quando haviam sido realizadas seis aplicações de enxofre em cobertura, resultando nas doses totais de 0; 80; 160 e 240 kg ha-1 de S, o que corresponde a 0; 400; 800 e 1200 kg ha-1 do fertilizante sulfato de amônio. Foram determinadas as seguintes características: açúcares redutores, açúcares totais, sacarose, sólidos solúveis, pH, acidez titulável, proteína, pigmentos (clorofila a, b, antocianinas e carotenoides totais) e o índice relativo de clorofila (índice SPAD). No capítulo 3 foi verificado os teores de N, P, K, Ca, Mg e S nas folhas comerciais coletadas na 2ª, 3ª e 4ª colheita, com quatro aplicações de enxofre em cobertura nas doses totais de 0; 53,32; 106,68 e 160 kg ha-1 de S, correspondendo a 0; 266,6; 533,4 e 800 kg ha-1 do fertilizante sulfato de amônio. Pode-se concluir que a aplicação destas doses de enxofre em cobertura, bem como o preparo do solo com gesso e composto orgânico e a combinação das duas técnicas, não afetam a produção e os teores de açúcares redutores, sólidos solúveis, pH, acidez titulável, proteína, clorofila a, b; carotenoides, antocianinas presentes em folhas comerciais de couve-de-folha. A utilização do gesso e composto orgânico no preparo de solo resulta em valor inferior do índice SPAD em folhas comerciais de couve-de-folha. Para esta característica, os resultados são superiores quando se utiliza apenas o composto orgânico no solo. O uso destas doses de enxofre em cobertura não interfere no índice SPAD das folhas comerciais de couve-de-folha. A ordem decrescente dos teores de macronutrientes nas folhas foi K>N>Ca>Mg>S>P. Conclui-se que quando se utiliza composto orgânico ou gesso antes do plantio, não há a necessidade de se utilizar enxofre em cobertura.
The kale stands out for being a vegetable very cultivated and consumed in the state of São Paulo, in Brazil and worldwide. Considering that the brassicas are demanding in sulfur, and due to the lack of data and research carried out with this nutrient in the kale culture, the objective of this work was to evaluate the need of sulfur associated with nitrogen in coverage in nutrition, production and physicochemical characteristics of kale cultivated with gypsum and organic compost at planting. The work was carried out at São Manuel Experimental Farm, belonging to the Faculty of Agronomic Sciences (FCA) of Universidade Estadual Paulista (UNESP), Campus de Botucatu, located in the municipality of São Manuel-SP. An experiment was carried out in which twelve treatments were studied, in a subdivided plots scheme, three types of soil preparation in the plots, and four sulfur doses covering the subplots. Three types of soil preparation were adopted: organic compost (30 t ha-1); agricultural gypsum (1.2 t ha-1) and organic compost (30 t ha-1) plus agricultural gypsum (1.2 t ha-1), incorporated in pre-planting. In Chapter 1, seven applications of sulfur in coverage were performed, resulting in total doses of 0; 93.31; 186.69 and 280 kg ha-1 of S, corresponding to 0; 465.5; 931 and 1400 kg ha-1 of ammonium sulfate. The following characteristics were evaluated: stem diameter, total length and width of commercial leaves, number and fresh mass of commercial leaves per plant, dry mass and yield (t ha-1). In order to evaluate the physical and chemical characteristics of the leaves in chapter 2, leaves of the 6th harvest were used, when six sulfur applications had been carried out in the cover, resulting in the total doses of 0; 80; 160 and 240 kg ha-1 of S, which corresponds to 0; 400; 800 and 1200 kg ha-1 of ammonium sulfate fertilizer. The following characteristics were determined: reducing sugars, total sugars, sucrose, soluble solids, pH, titratable acidity, protein, pigments (chlorophyll a, b, anthocyanins and total carotenoids) and relative chlorophyll index (SPAD index). The N, P, K, Ca, Mg and S contents of the commercial leaves collected in the 2nd, 3rd and 4th harvest were verified in chapter 3, with four applications of sulfur in coverage at the total doses of 0; 53.32; 106.68 and 160 kg ha-1 of S, corresponding to 0; 266.6; 533.4 and 800 kg ha-1 of the ammonium sulfate fertilizer. It can be concluded that the application of these sulfur doses as well as the preparation of the soil with gypsum and organic compost and the combination of the two techniques does not affect the production and the contents of reducing sugars, soluble solids, pH, titratable acidity , protein, chlorophyll a, b; carotenoids, anthocyanins present in commercial leaves of kale. The use of gypsum and organic compost in the soil preparation results in a lower SPAD value in commercial leaves of kale. For this characteristic, the results are superior when only the organic compound is used in the soil The use of these sulfur doses in coverage does not interfere with the SPAD index of commercial leaves of kale. The decreasing order of the macronutrient contents in the leaves was K> N> Ca> Mg> S> P. It is concluded that when organic compost or gypsum is used before planting, there is no need to use sulfur in coverage.
The kale stands out for being a vegetable very cultivated and consumed in the state of São Paulo, in Brazil and worldwide. Considering that the brassicas are demanding in sulfur, and due to the lack of data and research carried out with this nutrient in the kale culture, the objective of this work was to evaluate the need of sulfur associated with nitrogen in coverage in nutrition, production and physicochemical characteristics of kale cultivated with gypsum and organic compost at planting. The work was carried out at São Manuel Experimental Farm, belonging to the Faculty of Agronomic Sciences (FCA) of Universidade Estadual Paulista (UNESP), Campus de Botucatu, located in the municipality of São Manuel-SP. An experiment was carried out in which twelve treatments were studied, in a subdivided plots scheme, three types of soil preparation in the plots, and four sulfur doses covering the subplots. Three types of soil preparation were adopted: organic compost (30 t ha-1); agricultural gypsum (1.2 t ha-1) and organic compost (30 t ha-1) plus agricultural gypsum (1.2 t ha-1), incorporated in pre-planting. In Chapter 1, seven applications of sulfur in coverage were performed, resulting in total doses of 0; 93.31; 186.69 and 280 kg ha-1 of S, corresponding to 0; 465.5; 931 and 1400 kg ha-1 of ammonium sulfate. The following characteristics were evaluated: stem diameter, total length and width of commercial leaves, number and fresh mass of commercial leaves per plant, dry mass and yield (t ha-1). In order to evaluate the physical and chemical characteristics of the leaves in chapter 2, leaves of the 6th harvest were used, when six sulfur applications had been carried out in the cover, resulting in the total doses of 0; 80; 160 and 240 kg ha-1 of S, which corresponds to 0; 400; 800 and 1200 kg ha-1 of ammonium sulfate fertilizer. The following characteristics were determined: reducing sugars, total sugars, sucrose, soluble solids, pH, titratable acidity, protein, pigments (chlorophyll a, b, anthocyanins and total carotenoids) and relative chlorophyll index (SPAD index). The N, P, K, Ca, Mg and S contents of the commercial leaves collected in the 2nd, 3rd and 4th harvest were verified in chapter 3, with four applications of sulfur in coverage at the total doses of 0; 53.32; 106.68 and 160 kg ha-1 of S, corresponding to 0; 266.6; 533.4 and 800 kg ha-1 of the ammonium sulfate fertilizer. It can be concluded that the application of these sulfur doses as well as the preparation of the soil with gypsum and organic compost and the combination of the two techniques does not affect the production and the contents of reducing sugars, soluble solids, pH, titratable acidity , protein, chlorophyll a, b; carotenoids, anthocyanins present in commercial leaves of kale. The use of gypsum and organic compost in the soil preparation results in a lower SPAD value in commercial leaves of kale. For this characteristic, the results are superior when only the organic compound is used in the soil The use of these sulfur doses in coverage does not interfere with the SPAD index of commercial leaves of kale. The decreasing order of the macronutrient contents in the leaves was K> N> Ca> Mg> S> P. It is concluded that when organic compost or gypsum is used before planting, there is no need to use sulfur in coverage.
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Brassica oleracea L. var. acephala, Adubação orgânica, Gessagem, Produção vegetal, Qualidade, Nutrição de plantas