Phosphorus fractions in sandy soils of vineyards in southern Brazil

Abstract

SUMMARYPhosphorus (P) applications to vineyards can cause P accumulation in the soil and maximize pollution risks. This study was carried out to quantify the accumulation of P fractions in sandy soils of vineyards in southern Brazil. Soil samples (layers 0-5, 6-10 and 11-20 cm) were collected from a native grassland area and two vineyards, after 14 years (vineyard 1) and 30 years (vineyard 2) of cultivation, in Santana do Livramento, southern Brazil, and subjected to chemical fractionation of P. Phosphorus application, especially to the 30-year-old vineyard 2, increased the inorganic P content down to a depth of 20 cm, mainly in the labile fractions extracted by anion-exchange resin and NaHCO 3 , in the moderately labile fraction extracted by 0.1 and 0.5 mol L -1 NaOH, and in the non-labile fraction extracted by 1 mol L -1 HCl, indicating the possibility of water eutrophication. Phosphorus application and grapevine cultivation time increased the P content

The Pear Tree Response to Phosphorus and Potassium Fertilization

“…The interaction between the oxygen of the phosphate and the cation of the functional group, especially the aluminol of the clay minerals, and the Fe-OH and Al-OH groups of the oxide surface, leads to the occurrence of binding with different degrees of energy (BARROW et al, 1998). However, over the years, continued applications of P on the soil surface may cause occupation of the adsorption sites, leading to a decrease in their adsorption energy, which may increase desorption and, consequently, migration in the profile of soils planted to fruit-bearing plants ( SCHMITT et al, 2013), increasing content of the nutrient in deeper layers, as observed in the 10-20 cm layer, where there was an increase in available P with the increase in the rate of phosphate fertilizer in all the crop seasons. The available P content, in general, increased in the 0-10, 10-20 and 0-20 cm layers along with the rate of phosphate fertilizer applied in all the crop seasons evaluated (Table 3).…”

“…The application of P sources in the soil promotes phosphate sorption in the functional groups of inorganic reactive particles of the soil, but as successive applications occur, the binding energy between the phosphate and the functional groups decreases, and there may also be P migration in the soil profile (SCHMITT et al, 2013). In the same way, but in a readier manner, K migration occurs, as long as the quantity added is greater than that used by the crops, because its adsorption to the functional groups of inorganic and organic reactive particles takes place with low binding energy, facilitating its migration in the soil profile (KAMINSKI et al, 2007).…”

‘Fuji’ Apple Tree Response to Phosphorus Fertilization

“…The P applied on the soil surface during maintenance fertilization can be adsorbed with high binding energy with the mineral fraction surface of the soil (SCHMITT et al, 2013;BRUNETTO et al, 2015). However, successive applications of P onto the soil surface may cause the occupation of adsorption surfaces, decreasing their adsorption energy, which can enhance desorption and therefore migration in the soil profile, increasing the P amount in deeper layers.…”

Uso da terra e atributos de solos do estado do Rio Grande do Sul

“…A olericultura convencional apresentou os maiores teores de P diferindo dos valores obtidos para viticultura e mata nativa. As características desses solos (originados de basalto, com textura média a argilosa) e o método de extração do P, indicam que este elemento foi adicionado sob formas orgânicas, mas permanece no solo após a mineralização (Novais & Smyth, 1999;Schmitt et al, 2013).…”