The distribution of phosphorus forms and fractions in Retisol under different soil liming management

Abstract

Investigations on phosphorus (P) distribution in a naturally acid and limed moraine loam, Bathypogleyic Dystric Glossic Retisol were conducted in a site of a long-term experiment at the Vėžaičiai Branch of Lithuanian Research Centre for Agriculture and Forestry in 2008 and 2011. The aim of the present study was to determine the distribution of different phosphorus forms and fractions in naturally acid soil limed for a long time (62 years). During this study different amounts (18.4 and 104.9 t ha -1 ) of lime materials were incorporated into the soil and affected the formation of two soil pH KCl levels -acidic (5.6) and near to neutral (6.7). Seven different organic and mineral phosphate fractions and plant-available phosphorus were determined in the soil. The long-term soil liming was found to have no significant effect on the total P content and its distribution, but caused the changes in the proportions between the different phosphorus forms. Major part of mineral (74.02-83.68%) and organic (88.9-93.8%) P was composed of Al and Fe phosphates. Soil liming using ×2.0 liming rates every 3-4 years influenced a significant increase of the phosphates (AlPO 4 and Al(Fe)PO 4 ) little-available to plants obtained by the second cycle of extraction. It was determined that when soil pH becomes near to neutral, water soluble and plant-available P increases compared to its value measured at native pH. Increase of soil pH KCl till 6.7 had a significant effect on the amount of little plant-available Ca phosphates and less soluble organic phosphorus fraction amount in soil. The relatively optimal amounts of phosphorus fractions available for plants were determined in the soil with a pH KCl of 5.6, achieved by liming with a 0.5 rate every 7 years.

Fractionation and availability of phosphorus in acid soils of Hagereselam, Southern Ethiopia under different rates of lime

“…It increased from 14.2 to 53.1 mg kg (Table 3). Similar results were reported by Hartono et al [8] and Jokubauskaite et al [10]. It is likely related to an increase in adsorption and precipitation of P with the addition of excess Ca derived from lime.…”

“…Analysis of the organic P fractional composition showed that the major portion of the total extractable organic P was extracted by NaOH solutions (Table 3). These phosphorus compounds are more readily mineralized because they are constituents of the newly incoming organic residues as well originating from cells of microorganisms [10]. Although not statistically significant, the organic P contained in both NaOH and HCl fractions decreased with addition of lime.…”

“…Therefore, liming of these acidic Ethiopian soils is anticipated to have a large positive impact on increasing P availability for crop production. Several reports have shown that liming results in increase in labile P [8,10]. Liming intensity also affects the distribution of phosphorus among the fractions in the soil.…”

“…Analysis of the Pi fraction (resin, NaHCO 3 -Pi, NaOH-Pi, and HCl-Pi) revealed that the major part of mineral phosphorus (66.6-89.7% of total mineral phosphorus) was composed of Al + Fe phosphates (extracted by NaOH-Pi) ( Table 2). These could be due to the presence of high Al and Fe oxides and hydrous oxides with large specific surface areas, which provide large number of adsorption sites [10,26]. As the amount of lime added increased, the concentration of Al + Fe-P decreased significantly from 182.3 to 113.7 mg kg −1 (Table 3) as the P associated with Al and Fe hydrous oxides is transformed and released by desorption reactions to increase plantavailable phosphorus pools in soil such as water soluble P [10] and NaHCO 3 -Pi and PO fractions.…”

Characteristics of municipal landfill leachate and its impact on surrounding agricultural land

“…The P concentration was observed slightly higher in site 2 than the other sites. The available P concentration was very low compared with total P concentration, might be due to the abundance of Fe in the soil that may fix the excess phosphorus (Jokubauskaitė et al 2015). The total K concentration shows almost similar result in soil of all sites.…”