89 resultados para Neossolo Quartzarênico
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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Pós-graduação em Agronomia - FEIS
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Pós-graduação em Agronomia (Ciência do Solo) - FCAV
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conduziu-se este trabalho, com o objetivo de estudar as respostas fisiológicas de cinco genótipos de eucalipto à disponibilidade hídrica e adubação potássica. As mudas foram plantadas em vasos preenchidos com sete litros de um Neossolo Quartzarênico, com baixo teor natural de potássio (0,2 mmol c.dm-3 K), e submetidas a dois regimes de irrigação (RI1 - diário e RI2 - irrigação suspensa até o aparecimento de sintomas iniciais de murcha), sem (K0) e com suprimento de potássio (K1 - 200 mg.dm-3 K2O), em casa de vegetação. Avaliou-se a taxa fotossintética (A), condutância estomática (gs), transpiração (E), índice de conteúdo de clorofila (ICC), conteúdo relativo de água (CRA), eficiência fotoquímica (Fv/Fm), eficiência intrínseca (EUAintr) e instantânea no uso da água (EUAinst) e potencial hídrico foliar (Ψf). O experimento foi estabelecido no delineamento de blocos ao acaso, em esquema fatorial 5 x 2 x 2 (5 genótipos, 2 regimes de irrigação e 2 níveis de adubação potássica), com cinco repetições. À exceção da eficiência fotoquímica, as demais características apresentaram alterações significativas no regime RI2, com redução nos valores de A, gs e E e aumento em ICC e EUAinst. O suprimento de potássio nas plantas do RI2 proporcionou maiores valores de A, gs, E e CRA. Dos genótipos avaliados, o G1 é o mais resistente e o G2 o mais sensível à deficiência hídrica. Conclui-se que a adubação potássica pode amenizar os efeitos negativos da deficiência hídrica nos estádios iniciais de crescimento de eucalipto.
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The objective of this study was to evaluate the growth, the morphological alterations and the mineral composition of brazilwood (Caesalpinia echinata) plants caused by mineral nutrients omission in a green house experiment. The experimental units were distributed in the green house according to a completely random design. The treatments, each repeated five times, were the following : check (natural soil), complete (N, P, K, Ca, Mg, S, B, Cu, Mn, and Zn) and a complete solution but for the omission of one of the nutrients in parenthesis. Each plot was represented by a plant growing in a 7 dm3 vase filled with Quartzarenic Neosol. The analyzed variables were the following: visual nutritional deficiency symptoms, plant height, stem diameter, shoot dry matter, stem, branches and leaves included, and leaf nutrients level. The omission of nitrogen limited plant growth in height and shoot biomass production. The first visual deficiency symptoms were those due to N omission followed by those caused by P, Ca, Mg, S, Cu, and Mn omissions. Later on the K and B deficiency symptoms became visible. The omission of a nutrient always caused its level in the leaves to be significantly lower than that found when it was not omitted.
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Intercropping could efficiently prevent soil nutrient losses caused by extensive agriculture. The present study aimed to assess the effect of green manure on the nutritional status of orange trees cultivar 'Pera' (Citrus sinensis (L.) Osbeck). The plants were grafted on 'Cravo' lime trees and were then planted in a 7x4m space. Four different treatments corresponding to the evaluated green manures were employed: jack bean (JB) (Canavalia ensiformis DC), lablab (LL) (Dolichos lablab L.), pigeon pea (PP) (Cajanus cajan L. Millsp), and Brachiaria (BQ) (Brachiaria brizantha Hochst ex A. Rich. Stapf) as control. The experimental design was in randomized blocks, in split-plot time, with six replicates, with four treatments (green manures) and two plants per evaluation. The nutritional status was assessed by using the DRIS method (Diagnosis and Recommendation Integrated System); the yield and the macro and micronutrient levels contained in green manures and in the control was also determined. The nutritional diagnosis indicated that, in the two years of experiment, plants treated with green manure showed better nutritional balance index compared to Brachiaria. This suggests that, over time, green manure can lead to better nutritional balance. Pigeon pea treatment showed the highest yields, compared to control, in the two evaluated crop cycles (2004/05 and 2005/06).
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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The increased use of herbicides, coupled with inadequate use of these molecules, also increased concerns about the risks of environmental contamination and its effects on humans and animals. The objective of this work evaluates the potential for leaching of herbicides in the crop of cane sugar, in contrasting soils. Used samples were used Psament (NR - sandy texture) and Oxisol Red (LR - clay texture). After application of herbicides ametryne (NR 1.60 kg ha(-1) and LR 2.40 kg ha(-1)), clomazone (NR 0.90 kg ha(-1) and LR 1.10 kg ha(-1)) and diuron (NR 1.60 kg ha(-1) and LR 3.20 kg ha(-1)), were irrigated blades of 0, 20, 40, 60, 80 and 100 mm of water in soil columns. Results indicate that ametryne in NR samples submitted to the handling layer of 5-10 cm when applied blades of 20 and 40 mm of water. It was evident that the clomazone, regardless of the soil, did not exceed 0-5 cm water depths of 0 to 20 mm of water and 5-10 cm deep in the blades above 40 mm of water. With blades up to 80 mm, the diuron leaching only in layers 0-5 cm deep in LR. Conclude that the potential of leaching of diuron and ametryne was influenced by soil texture together with the organic matter content, the same was not true for clomazone.
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Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA
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The objective of the study was to analyze the features of the relief through the variables: maximum altitude (HM); mean altitude (Hmd); minimum altitude (Hm); altitude range (H); average slope length (CVm); minimum length of run-off (Cd) and average steepness of circular samples (I) of the Capivara River Watershed – Botucatu (SP). A total of 4 circular samples were obtained per unit of soil (Quartzipsamment alfisol oxisol - RQ, Udox - LVA and Udorthent - RL). Multivariable analysis and aerial color photographs of 2000, Brazilian Chart and Soil Chart of Botucatu city-SP were used for data analyses. Soil differentiation was performed using the Student-t Test for analyzes of orthogonal contrasts among means of the three soils and analysis of groupings and major components. The grouping analysis of the variables of relief differentiated 75% of LVA and 100% of RL and RQ soil circular samples. The most efficient parameters of relief for differentiation of soils according to their order of importance were as follows: HM, Hm, Hmd and H.