Gypsum and other sulfur materials for soil conditioning /

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Crop nutrient application rates

This guide provides information on how to match nutrient rate to crop needs by varying application rates and timing between blocks, guided by soil tests, crop class, cane variety, soil type, block history, soil conditioners and yield expectations.

Avaliação de condicionadores em solo para uso em telhados verdes com vistas à retenção hídrica.

As inundações são fenômenos naturais que ocorrem devido às chuvas de grande magnitude, agravadas nas áreas urbanas pela impermeabilização do solo e ineficiência dos sistemas de drenagem. Os telhados verdes surgem como uma medida compensatória estrutural que pode reter parte da água precipitada, adiando o pico de escoamento. O objetivo deste trabalho foi de desenvolver uma combinação de solo e condicionadores para telhado verde, promovam um aumento relevante na capacidade de retenção hídrica e um maior adiamento do pico de escoamento das águas pluviais. Este estudo foi dividido em duas etapas. Na Etapa 1, foram analisadas, em colunas de percolação, três condicionadores nas seguintes concentrações: Gel retentor Stockosorb (2; 4; 6 g/dm3), Fertilizante de liberação lenta Osmocote (4,7; 7,1; 9,0 g/dm3) e Zeólita (30; 50; 70 g/dm3), em três eventos (regas) consecutivos de chuva simulada na intensidade de 57 mm/h. A avaliação das concentrações mais adequadas dentre as testadas para cada condicionante foi baseada nas análises referentes à retenção hídrica (altura do meio após a rega; tempo de adiamento do escoamento; mm retidos; intensidade da água percolada em mm/min) e à qualidade da água percolada (pH, oxigênio dissolvido, turbidez e sólidos). Na Etapa 2, foi avaliada, em vasos, a influência da presença de três espécies de plantas (Arachis pintoi; Raphanus sativus; Lavandula angustifolia) em dois tipos de meio: solo sem condicionadores; solo com condicionadores nas melhores concentrações indicadas na Etapa 1, sendo simulada apenas um evento de chuva de 57 mm/h. Foram analisados parâmetros biológicos (germinação; plantas sobreviventes; comprimento do caule e da raiz; pesos da biomassa do caule e da raiz); retenção hídrica (altura do meio após a rega; tempo de adiamento do escoamento; mm retidos; intensidade da água percolada em mm/min); qualidade da água percolada (pH; oxigênio dissolvido; turbidez; sólidos; nitrato; amônia; fósforo total). Os resultados da Etapa 1 indicaram que o gel promoveu de forma significativa um aumento na retenção hídrica, e adiou o início da percolação de água, além de promover ligeira elevação do pH na água percolada. A adição de zeólita resultou em um aumento significativo da retenção hídrica, porém tal aumento não é vantajoso visto que este representa um custo adicional que poderia ser reduzido com o aumento da proporção do gel na coluna. A adição de fertilizantes não promoveu mudanças na qualidade da água percolada. Na Etapa 2, somente o efeito da presença de A. pintoi (maior produção de biomassa de raiz e caule) e R. sativus foram avaliadas. A presença dos condicionantes no solo proporcionou um desempenho significativamente superior em relação a retenção hídrica (altura do substrato e adiamento do pico de chuva) e qualidade da água percolada (pH e turbidez) quando comparados aos testes realizados na presença somente de solo. O fertilizante influenciou nas altas concentrações dos nutrientes (nitrogênio e fósforo) na água percolado nos resultados. A presença do gel no substrato, resultou numa capacidade superior de retenção de hídrica, e consequentemente no adiamento do pico de intensidade de chuva. Sendo assim, recomenda-se a aplicação do gel em telhados verdes para futuros estudos em ambientes externos.

新型土壤结构改良剂水分特性及其对玉米苗期的影响研究

试验采用室内研究的方法,探讨2种以环境废弃资源为主要原料的新型土壤改良剂的基本水分特性,验证其对玉米苗期的影响。试验结果表明,2种改良剂在不同溶液中溶胀度不同,PJG在蒸馏水中溶胀度最大,PFL则是在自来水中吸水能力最强。PFL的吸水速率要低于PJG,单位质量最大吸水量1.705,为PJG的46.9%。2种改良剂对玉米出苗率的影响不是很明显,但能显著地提高玉米苗期株高和叶面积,对苗期土壤水分的散失也起到了很好的抑制作用。2种改良剂都能明显提高玉米苗期水分利用效率,最优水平分别高于对照27.89%和58.99%。综合各方面结果,建议在玉米试验中使用PJG的最佳浓度为0.8%,PFL为0.05%。

Mineralogical and chemical characterization of some vermiculites from the mozambique belt of tanzania for agricultural use

Vermiculite minerals are locally available in the Mozambique Belt of Tanzania but are not currently commercially exploited. In part this may be due to lack of any precise characterization. This study was carried out as a first step to assess the suitability of these vermiculites for crop production by characterization of their mineralogical and chemical compositions. X-ray diffraction and scanning electron microscopy combined with an energydispersive X-ray system were used to establish the mineralogy. Electron microprobe analysis and inductively coupled plasma-mass spectrometry were used to study the chemical compositions and to identify any possible issues related to chemical composition that might affect their use if applied as soil conditioners. The samples were characterized as vermiculites and hydrobiotites with a wide variety of accessory minerals. Accessory minerals that might be of some concern are galena, fibrous amphiboles and sepiolite. The total levels of Ni in all vermiculites, and Cr in some, were also found to be high relative to common European standards and this might limit their potential as soil conditioners. It is clear that a field assessment of the bioavailability of various elements would be necessary before decisions relating to potential agricultural use could be made. © 2009 The Mineralogical Society.

Quantificação de macronutrientes no solo e em folhas de cana-de-açúcar em função de doses de resíduo da mineração de bauxita

The experiment was carried out in green house with the objective of evaluating the effect of the bauxite mining residue in the rates of macronutrients in sugarcane and soil. Containers of 10 L were used. They received the following rates of bauxite residue: 0; 28; 56; 84; 112 and 140 t ha(-1). The used culture was the sugarcane (SP92 4221). The incorporation of the bauxite residue in the soil provided an increase in the levels of the soil macronutrients, and only for sulphur levels above 83 t ha(-1), it was possible to provide reductions of this nutrient. For rates of determined macronutrients in the leaf, levels above 70, 5; 125; 101; 56 t ha (-1) diminished the rates of nitrogen, phosphorum, potassium and sulphur, respectively. However, for calcium and magnesium the use of the residue provided the reduction of leaf rates. The level of the bauxite residue which had the largest production of dry mass was 64 t ha(-1).

Condicionadores químicos do solo e seus efeitos sobre os Índices físicos

Dois condicionadores químicos, a carboximetilcelulose, nas dosagens de 0,1% e 0,25% em relação ao peso do solo seco, e o silicato de sódio, de relação sílica-álcali igual a 3,2, a 0,6% e 1,2% em peso, foram pesquisados quanto aos seus efeitos sobre os índices físicos dos solos argiloso e barro arenoso empregados neste trabalho. Os dados obtidos foram estatisticamente analisados e os resultados permitiram que se chegassem a algumas conclusões. O tratamento 0,25% de carboximetilcelulose diminuiu o peso específico aparente seco e aumentou, consequentemente, o índice de vazios e porosidade dos solos estudados. O efeito dos tratamentos 1,2% de silicato de sódio e 0,1% de carboximetilcelulose sobre o peso específico aparente seco dos solos argilosos e barro arenoso, respectivamente, foi semelhante ao do tratamento 0,25% de carboximetilcelulose.

Avaliação do estado nutricional de mudas de Gonçalo Alves (Astronium Fraxinifolium)

The planting of seedlings, the establishment and maintenance of the natural regeneration process, or the combination thereof, are methods used in the recovery of degraded or disturbed environments, however, often require the addition of soil conditioners. This study aimed to evaluate the influence of conditioners, introduced in degraded soil on growth and nutritional status of Astronium fraxinifolium seedlings. To conduct the experimentation were used as degraded soil conditioner, ash from sugarcane bagasse (CZ) and macrophytes (MC), at the doses of 0, 15, 30 and 45 t ha-1 and 0, 16 and 32 t ha-1 respectively, which combined produced 12 treatments, with three replications, and for field installation, was used the experimental randomized block design. Astronium fraxinifolium (Gonçalo Alves) seedlings, native tree species in cerrado, were introduced in the experimental area and, after 12 months, were evaluated for leaf concentration of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, iron, manganese and zinc (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn, respectively). Seedlings and adult plants of A. fraxinifolium were collected in preserved cerrado reserve were also analyzed for nutrients foliar concentration to perform a comparative analysis. The leaves collection in the preserved cerrado and experimental area, was accompanied by soil sampling (0.0 - 0,20 m deep), which was analyzed for phosphorus, OM (organic matter), pH, K, Ca, Mg, Al+H (potential acidity), Al (aluminum), Cu, Fe, Mn and Zn. The results show that the applied residues contributed to raise the foliar concentration of Cu and Fe. The foliar concentration of nutrients was higher in A. fraxinifolium seedlings from preserved cerrado, except for B, which was similar between areas, besides Cu and Fe with higher levels in the seedlings from experimental area. The combined addition of residues (MC and CZ), led to increase the plants height and diameter. This...

Emissão de gases do efeito estufa e estoque de carbono no sistema solo-planta em área com aplicação superficial de calcário e gesso em experimento de longa duração

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese, caracterização e aplicação de hidrogéis nanoestruturados contendo nanoargila para melhorar a germinação e qualidade de muda de hortaliça

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

ORGANIC RESIDUE AND PHOSPHORUS AS CONDITIONERS OF DEGRADED SOIL AND EFFECTS ON THE INITIAL GROWTH OF Dipteryx alata Vog.

In northwestern Sao Paulo State, it was established, in 1965, the hydroelectric station of Ilha Solteira (CESP) that produced extensive degraded areas, from where it was removed the soil superficial layers. For the re-establishment of the vegetation, in areas like these, it is necessary the addition of chemical inputs and organic material. Associating the presence in the area of macrophytes, to the need of recovery of degraded areas and the availability of seeds from native species of Cerrado, it was intended the development of this work, with the objective of evaluating the addition effects of organic residue and phosphorus on the material of degraded soil and on the initial growth of Dipteryx alata, arboreal species of 'cerrado'. The soil material was collected in area of degraded soil by the construction of Ilha Solteira hydroelectric station. The experiment was conducted in two environmental conditions, greenhouse and plenty of sun. The treatments consisted of four phosphorus doses (0, 100, 200 and 300 mg dm(-3) of P2O5), with or without macrophytes addition, with 16 treatments and 10 repetitions each one. The used macrophytes, collected at Jupia hydroelectric station, in Mato Grosso do Sul state, were dried, sliced, incorporated to the soil material and incubated during 60 days. The seeds of Dipteryx alata, collected around of the area, were sowed in washed sand and after 60 days introduced in the treatments. The plants were appraised monthly for height, stem diameter and leaves chlorophyll. After 210 days, the plants were collected and evaluated for fresh and dry weight of aerial part and radicular system and the soil material was evaluated for fertility and microbial activity by the carbon of liberated CO2. The organic residue, incorporated to the material of soil degraded, positively affects the soil fertility and the soil microbial activity. The applied phosphorus doses influenced the behavior of Ca, SB, H+Al and CTC, when applied in the absence of organic residue, it promoted significant and linear increments for values of potential acidity, and indicated the organic residue importance. The initial growth of the Dipteryx alata was favored by the protected cultivation, for the incorporation of organic residue and for the phosphorus addition to the soil. At the end although the material of degraded soil comes as good perspective for disposal of this residue, studies about the field conditions are necessary.

Ball Response and Traction of Skinned Infields Amended with Calcine Clay at Varying Soil Moisture Contents

The skinned portions of baseball and softball infields vary widely with respect to soil texture, applied amendments and conditioners, and water management. No studies have been reported that quantify the effects of these varying construction and maintenance practices on the playability of the skinned portions of infields. In Connecticut, USA, skinned infield plots were constructed from five different soils (silt loam, loam, coarse sandy loam, loamy sand, loamy coarse sand) and amended with four rates of calcined clay (0, 4.9, 9.8, 19.6 kg m–2) to determine the effects on surface hardness, traction, and ball-to-surface friction (static and dynamic) at varying soil moisture contents (10, 14, and 18%). Bulk density, saturated hydraulic conductivity, and shear strength of the different soil–calcined clay rate combinations were determined. Increasing the rate of calcined clay decreased bulk density and shear strengths, and increased saturated hydraulic conductivity. Surface hardness increased more with coarse-textured soils and increasing calcined clay rate, but decreased more with fine-textured soils and increasing soil moisture. Increasing the calcined clay rate resulted in decreases in ball-to-surface static friction across all soils and decreased dynamic friction with the fine-textured soils. Increases in soil moisture increased friction in all soils. The fine-textured soils had greater traction than the sandy soils, but no consistent calcined clay or moisture effects on traction were observed. Shear strength of the soils was highly correlated with traction and friction. The results suggest that differences in skinned infield soils are quantifiable, which could lead to the development of playing surface standards.