Soybean response to zinc fertilization in soil with contents above critical level

O objetivo deste trabalho foi avaliar a resposta da soja a estratégias de adubação com zinco, em Latossolo com disponibilidade inicial do micronutriente acima do nível crítico. O experimento consistiu em 16 tratamentos com diferentes combinações de fontes, doses e formas de aplicação de Zn. Foram avaliados a produtividade da soja e os teores de Zn no solo, nas folhas e nos grãos. A fertilização com Zn aumentou a produtividade da soja, mesmo em solo com teor do micronutriente acima do nível crítico. A resposta à adubação varia de acordo com as estratégias de aplicação de zinco. Há indícios de que o nível crítico de Zn no solo deve ser revisto.The objective of this work was to evaluate the response of soybean to strategies of zinc fertilization in an Oxisol with initial availability of the micronutrient above the critical level. The experiment consisted of 16 treatments combining different sources, doses, and modes of Zn application. Soybean yield and Zn content in soil, leaves, and grains were evaluated. Zinc fertilization increased soybean yield, even in a soil with the micronutrient availability above critical level. Response to fertilization varies according to zinc application strategies. There is evidence that Zn critical level in soils should be revised

Resposta da soja à adubação com zinco em solo com teores acima do nível crítico

O objetivo deste trabalho foi avaliar a resposta da soja a estratégias de adubação com zinco, em Latossolo com disponibilidade inicial do micronutriente acima do nível crítico. O experimento consistiu em 16 tratamentos com diferentes combinações de fontes, doses e formas de aplicação de Zn. Foram avaliados a produtividade da soja e os teores de Zn no solo, nas folhas e nos grãos. A fertilização com Zn aumentou a produtividade da soja, mesmo em solo com teor do micronutriente acima do nível crítico. A resposta à adubação varia de acordo com as estratégias de aplicação de zinco. Há indícios de que o nível crítico de Zn no solo deve ser revisto

AVALIAÇÃO DE MÉTODOS DE EXTRAÇÃO DE SILÍCIO E FÓSFORO EM AMOSTRAS DE SOLOS

The aim of this study was to evaluate silicon (Si) and two phosphorus (P) extraction methods in "Latossolos" under corn and sorghum. The experiments were conducted in green-house, in a completely randomized, with corn for the 5x2x2 factorial arrangement, consisting of five P rates (0, 96, 192, 288 and 480 mg dm-3) in the absence and the presence of 300 mg dm-3 of slag in two "Latossolos" and four replicates, while for sorghum the experimental design was 5x2, and is used only one soil. The experimental plots were subjected to two incubation periods, the first with slag (only half of the plot) and then with lime. In the first experiment two plants were cultivated corn pot for 45 days and then ten plants of sorghum for 60. After the experiments took place the collection of plants being evaluated for plant height, stem diameter and dry weight of maize shoots and just shoot dry matter of sorghum, the levels of Si and P in samples soil and plants. The medium texture soil showed better correlations of Si and P. For the Olsen P method as both the Mehlich 1 had good correlation. Sorghum showed higher correlation coefficients than corn

EXTRACTION OF SILICON IN SOILS FERTILIZED WITH PHOSPHATE AND SILICATE EXTRAÇÃO DE SILÍCIO EM SOLOS FERTILIZADOS COM FOSFATO E SILICATO

<p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY"><span style="color: #000000;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;">The objective of this study was to evaluate the levels of silicon (Si) extracted by using calcium chloride and acetic acid solutions, in Haplortox soil samples fertilized with phosphate and silicate. The experimental design was completely randomized, in a 5x2 factorial scheme, consisting of five doses of phosphorus (P) (0 mg dm<sup>-3</sup>, 96 mg dm<sup>-3</sup>, 192 mg dm<sup>-3</sup>, 288 mg dm<sup>-3</sup>, and 480 mg dm<sup>-3</sup>), in the absence and presence of 300 mg dm<sup>-3</sup> of Si. The experimental units were submitted to two incubation periods, the first with silicate (half of the portions) and the second with limestone (remaining of the portions). After incubation, the soil samples received the P doses and were cultivated with corn plants. The Si level in the soil, measured by using extracting solutions, and the Si and P contents in the dry matter of the aerial part were evaluated. Significant effect was observed for Si, phosphate levels, and for the interaction Si x phosphate doses, in relation to the Si content extracted from the soil. The acetic acid solution extracted more Si than the calcium chloride solution, independently of the slag fertilization.</span></span></span></p> <p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY"><span style="color: #000000;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><span lang="en-US">KEY-WORDS:</span><span lang="en-US"><strong> </strong></span><span lang="pt-PT"><em>Zea mays </em></span><span lang="pt-PT">L.</span><span lang="en-US">; slag; phosphorus; extractors.</span></span></span></span></p><p style="text-align: justify !important;"><span style="color: #000000;"><span style="font-family: Verdana, sans-serif;"><span style="font-size: x-small;"><span>O objetivo deste estudo foi avaliar os teores de silício (Si) extraídos por soluções de cloreto de cálcio ou ácido acético, em amostras de Latossolo Vermelho distroférrico, fertilizadas com fosfato e silicato. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 5x2, constituído pela combinação de cinco doses de fósforo (P) (0 mg dm<sup>-3</sup>, 96 mg dm<sup>-3</sup>, 192 mg dm<sup>-3</sup>, 288 mg dm<sup>-3</sup> e 480 mg dm<sup>-3</sup>), na ausência e presença de 300 mg dm<sup>-3</sup> de Si. As unidades experimentais foram submetidas a dois períodos de incubaç��o, o primeiro com escória (metade das parcelas) e o segundo com calcário dolomítico (restante das parcelas). Após a incubação, as amostras de solo receberam as doses de P e foram cultivadas com plantas de milho. Foram avaliados os teores de Si no solo, extraídos pelas soluções extratoras, e os conteúdos de Si e P, na matéria seca da parte aérea. Observou-se efeito significativo para o Si, doses de fosfato e para a interação Si x doses de fosfato, quanto aos teores de Si extraídos do solo. A solução de ácido acético extraiu mais Si do que a solução de cloreto de cálcio, independentemente da fertilização com escória.</span></span></span></span></p> <p class="western"><span style="color: #000000;"><span><span style="font-family: Verdana, sans-serif;"><span style="font-size: x-small;"><span lang="pt-BR"><span><span><span>PALAVRAS-CHAVE:</span></span></span></span></span></span></span></span><strong><span style="color: #000000;"><span><span style="font-family: Verdana, sans-serif;"><span style="font-size: x-small;"><span lang="pt-BR"><span><span><span> </span></span></span></span></span></span></span></span></strong><em><span style="color: #000000;"><span><span style="font-family: Verdana, sans-serif;"><span style="font-size: x-small;"><span lang="pt-PT"><span><span><span>Zea mays </span></span></span></span></span></span></span></span></em><span style="color: #000000;"><span><span style="font-family: Verdana, sans-serif;"><span style="font-size: x-small;"><span lang="pt-PT"><span><span><span>L.; </span></span></span></span></span></span></span></span><span style="color: #000000;"><span><span style="font-family: Verdana, sans-serif;"><span style="font-size: x-small;"><span lang="pt-BR"><span><span><span>Escória de siderurgia; fósforo; extratores.</span></span></span></span></span></span></span></span></p><p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR"><span style="font-family: 'Times New Roman', serif; font-size: x-small;"><br /></span></p&gt

EFEITO DA APLICAÇÃO DE BASALTO TRITURADO NAS CARACTERÍSTICAS QUÍMICAS DE AMOSTRAS DE SOLO DO ESTADO DE MATO GROSSO DO SUL

The objective was to evaluate the effect the soil chemical characteristics with the application crushed basalt doses soil samples in the Mato Grosso do Sul State. The experiment was installed in a completely randomized design with six treatments, represented by basalt ground doses (0.00, 12.50, 25.00, 37.50, 50.00 and 62.50 g dm-3) and three replications. Samples of 200 cm3 soil each, packed in polyethylene pots were incubated in the laboratory for 90 days with crushed basalt. At the end of the incubation the samples were dried in the air, passed through a sieve with mesh 2 mm opening, homogenized and subjected to chemical analysis of pH, aluminum, calcium, magnesium, potassium end potenciaty acidy. The values base saturation (V%) were calculated by the product of the bases sum per 100 divided by the cation exchange capacity at pH 7.0 (T). Concluded that the pH is shown with the greatest change the lower the power of packing the soil. With the application crushed basalt was very significant increases in the potassium levels. The biggest increases calcium and magnesium in the soils were poor in these nutrients

Características agronômicas da alface fertilizada com superfosfato triplo e ninhos de cupim

Resumo. O objetivo do trabalho foi avaliar as características agronômicas da alface em resposta à adubação com  superfosfato triplo e ninhos de cupim em amostras de Latossolo Vermelho distrófico. O experimento foi realizado no delineamento inteiramente casualizado, em esquema fatorial 3 x 5, sendo os tratamentos compostos por três doses de ninhos de cupim (0; 100 e 300 g dm-3) e cinco doses de superfosfato triplo (0; 112; 224; 336; 560 mg dm-3 ) com quatro repetições. As amostras do solo foram incubadas com diferentes doses de material orgânico por um mês e após receberam as doses do fertilizante fosfatado. Em seguida foram transferidas para vasos de polietileno e cultivadas com uma planta de alface em casa-de-vegetação. Ao final do ciclo da alface as plantas foram colhidas e avaliaram-se o número de folhas, a matéria fresca das raízes, do caule e das folhas e área foliar. A aplicação de ninhos de cupim e doses de superfosfato triplo promoveram acréscimos significativos nos atributos avaliados em relação a testemunha

Soil Type and Zinc Doses in Agronomic Biofortification of Lettuce Genotypes

The incidence of many malnutrition-related diseases among the populations of developing countries is closely related to low dietary zinc (Zn) intakes. This study evaluated the potential of agronomic biofortification of lettuce genotypes with Zn in different soils. We evaluated the ability to biofortify three lettuce genotypes (‘Grand Rapids’, ‘Regina de Verão’, and ‘Delícia’) in two soils (Red-Yellow Latosol and Dystroferric Red Latosol) using five doses of Zn (0, 5, 10, 20, and 30 mg kg−1). At 55 days after sowing, the plants were harvested. There was an interaction among the soils, genotypes, and Zn doses. Regardless of the soil and genotype, the increase in Zn supply promoted a linear increase in shoot Zn concentration. However, shoot and root dry matter yields were differentially affected by Zn supply according to the genotype and soil type. Overall, the Red-Yellow Latosol provided a higher shoot Zn concentration but also caused greater growth damage, especially in ‘Regina de Verão’ and ‘Delícia’. ‘Grand Rapids’ was biofortified the most in Red-Yellow Latosol