Influência de doses de calcário com diferentes relações cálcio: magnésio na produção de matéria seca e na composição mineral da alfafa

Gomes, Fernando Teixeira; Borges, Arnaldo Chaer; Neves, Júlio César Lima; Fontes, Paulo Cézar Rezende

doi:10.1590/s0100-204x2002001200015

Cited by 5 publications

(4 citation statements)

References 11 publications

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“…However, liming does not correct the acidity of the subsoil, and this procedure is not always easy to perform and economically viable [20,21]. In the specific case of alfalfa, liming has been recommended only when it is possible to have soil pH increased to at least 6.0 [22,17].…”

Section: Introductionmentioning

confidence: 99%

Performance of tetraploid alfalfa genotypes as exposed to aluminum toxicity

Passos

Köpp²,

Lédo³

2012

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A study was carried out to evaluate the development of 12 tetraploid alfalfa cultivars exposed to Al toxicity in nutrient solution. Newly germinated seedlings of cultivars Alfa 200, Alto, Araucana, Costera, Crioula, Esmeralda, Falcon, F-708, Rio, Romagnola, Valley Plus, and Victoria, were exposed to either 0, 4, 8 or 12 mg·L-1 Al3+. Plants were analyzed regarding root length (RL) and dry matter (RDM), aerial part length (APL), and dry matter (APDM), hypocotyl length (HypL) and dry matter (HypDM), epicotyl length (EpiL) and dry matter (EpiDM), and petiole length (PetL), and dry matter (PetDM). Results indicated that, although all genotypes exhibited detectable sensitivity to such a stress, cvs. Crioula, Victoria and Alpha-200 were tolerant to 4 mg·L-1 Al3+ toxicity. It was also concluded that Al3+ levels up to the 4 mg·L-1 will be effective for screening tetraploid alfalfa genotypes regarding this type of stress, when evaluations are made in nutrient solution. Finally, RL is the most suitable variable for conducting such evaluations, but all variables related to dry matter in the aerial part are also recommended

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Section: Introductionmentioning

confidence: 99%

Performance of tetraploid alfalfa genotypes as exposed to aluminum toxicity

Passos

Köpp²,

Lédo³

2012

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“…agrotec., Lavras, v. 29, n. 4, p. 786-794, jul./ago., 2005 Diversos trabalhos (GOMES et al, 2002;HUNTER, 1948;MOREIRA et al, 1999;SIMSOM et al, 1979) mostram que a produção da alfafa não é alterada, em razão das variações nas relações Ca e Mg do calcário. Bull (1986), estudando o efeito da relação K/(Ca+Mg) na produção de matéria seca, observou uma diminuição significativa na absorção de Ca e Mg quando houve elevação nessa relação com o aumento da concentração de K na solução do solo.…”

Section: Introductionunclassified

Relação cálcio e magnésio na fertilidade de um latossolo vermelho escuro distrófico cultivado com alfafa

2005

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RESUMORealizou-se com este trabalho com o objetivo de verificar os efeitos da relação Ca e Mg na fertilidade de um Latossolo Vermelho Escuro distrófico, fase cerrado, cultivado com alfafa (Medicago sativa L.). O delineamento experimental utilizado foi o inteiramente casualizado em parcelas subdivididas, com seis tratamentos e quatro repetições. Os tratamentos consistiram de cinco relações Ca:Mg: 1:0; 1:1; 2:1; 3:1 e 4:1 (3,9 t ha -1 ) e mais um tratamento adicional com a mesma relação 3:1, porém, com o dobro da quantidade aplicada (7,8 t ha -1 ). As quatro coletas de solo realizadas durante a condução do experimento consistiram nas subparcelas. Os resultados mostraram que com o aumento da relação K/(Ca+Mg) ocorre diminuição do teor de Ca e Mg na matéria seca da parte aérea e da quantidade Ca e Mg trocável, que as saturações de K, Ca e Mg estão diretamente relacionadas com a produção de matéria seca total e o aumento da relação K/(Ca+Mg) diminui o índice de pH e aumenta a acidez potencial do solo. Termos para indexação: Medicago sativa, K/Ca+Mg, saturação de K, saturação de Ca, saturação de Mg, fertilidade do solo. ABSTRACTThe objective of this work was to verify the effect of the calcium and magnesium ratio in the fertility of a dystrophic Dark Red Latosol (Oxisol), phase savanna, cultivated with alfalfa (Medicago sativa L.). The used experimental design was a randomized split-plot with four replicates. The treatments consisted of five Ca:Mg ratios 1:0; 1:1; 2:1; 3:1 and 4:1 at a recommended dosage of 3.9 t ha -1 and an additional treatment with the same ratio of 3:1, however with the double of the applied amount (7.8 t ha -1). Four soil samples were collected during the experiment consisting in the subtreatments. The results showed that with an increase of the relationship K/(Ca+Mg) a reduction of the Ca and Mg content of the aerial dry matter and of the exchangeable Ca and Mg content happens. The saturations of K, Ca and Mg are directly related with the total dry matter production and the increase of the relationship K/(Ca+Mg) reduces the pH index and increases the potential acidity of the soil.

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“…An increase in the K concentration in the soil solution was expected through its addition because increased soil saturation (70%) would make more K available in the soil solution by base fertilization and exchange of K; however, the presence of a large quantity, especially of Ca, in the increasing ratios of cations resulted in a competition Archives of Agronomy and Soil Science 5 with K. Nevertheless, according to Epstein and Bloom (2005), K uptake by the plant is not necessarily worsened by such competition. Likewise, others studies have also found that a decrease in K contents resulted with increasing ratios of Ca:Mg, as in experiments with alfalfa in Oxisols (Gomes et al 2002;Moreira et al 2005), maize in Inceptisols (Pintro et al 2005;Medeiros et al 2008), and peanut in the nutrient solution (Zharare et al 2010). Another preponderant factor is the soil's own capacity for retaining cations like K in accordance with the clay content.…”

Section: Results and Discussion Soilmentioning

confidence: 83%