Movimentação de cátions e ânions em colunas de solo influenciada pela calagem e cobertura vegetal

• Autor(a) principal: Ribeiro, Bruno Neves
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5519
• topic: Cálcio; Magnésio; Acidez; Ácidos orgânicos; Calcium; Magnesium; Acidity; Organic acids; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO

The effect of limestone may be limited to the region of its application, due to the low mobility of the products of its dissolution in the soil. Such mobility can be favored by organic acids of low molecular mass, which are released during the mineralization of plant residues. The present work aimed to evaluate the contribution of residues of three forage plant species for the mobility of the products of the dissolution of the limestone applied on the surface. Columns of soil were mounted in PVC tubes with 20 cm of height, in which Brachiaria decumbens cv. Australiano, Melinis minultiflora (molasses grass) and Stylosanthes guianensis var. vulgaris cv. Mineirão were cultivated. After 90 days of growth, limestone was applied (CaCO3 + MgCO3 p.a. with Ca:Mg molar relation of 3:1) on soil surface, according to the following treatments: T1 live plants, in other words, in activity, T2 cut plants and the material of the dried and ground aerial part (< 1 mm) applied on the surface of the soil, T3 cut plants, maintaining only the roots in the soil, T4 application of the material of the aerial part and T5- without application of the plant material, both in non-cultivated columns of soil. Columns without the application of limestone and plant material were also included as the control treatment (T6). Percolations were carried out with water equivalent to a volume of soil pores, determining the concentrations of Ca, Mg, K, inorganic anions (Cl-, CO3 2-, F-, NO3- and SO4 2-,) and organic acids (acetic, butyric, citric, malonic, oxalic and tartaric) in the leachate solutions. In the end of the experiment, the soil columns were separated into segments of 0 - 2,5, 2,5 - 5, 5 - 10, 10 - 15, 15 - 20 cm, in which the contents of Ca2+, Mg2+ and K were determined. It was observed that a higher limestone solubilization occurred in the soil in which plants were maintained alive. There was a distribution of Ca up to 10 cm of depth, regardless of the application of the plant materials. The application of limestone regardless of the application of the plant material promoted more K movement. The application of limestone and plant material of the forage plant aerial parts favored the increase in the lixiviation of Ca, Mg and K and acetic acid.